CN112881027A

CN112881027A - Method, device and system for determining automobile braking energy recovery efficiency

Info

Publication number: CN112881027A
Application number: CN201911205899.XA
Authority: CN
Inventors: 朱晓军; 郭海
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2021-06-01
Anticipated expiration: 2039-11-29
Also published as: CN112881027B

Abstract

The embodiment of the invention provides a method, a device and a system for determining the recovery efficiency of automobile braking energy. The method for determining the recovery efficiency of the automobile braking energy comprises the following steps: acquiring first brake state information of a test vehicle, wherein the brake state information comprises the speed of the test vehicle in the brake process, the voltage of a motor controller in the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the brake time of the test vehicle; and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in the embodiment of the present invention, the braking energy recovery efficiency is determined according to the voltage and the current of the motor controller and by combining with other data, so that the accuracy of the braking energy recovery efficiency of the vehicle in the braking process can be more accurately determined, and the accuracy of the evaluation result is improved when the vehicle is evaluated according to the braking energy recovery efficiency.

Description

Method, device and system for determining automobile braking energy recovery efficiency

Technical Field

The invention relates to the technical field of automobiles, in particular to a method, a device and a system for determining the recovery efficiency of automobile braking energy.

Background

Compared with the traditional fuel vehicle, the pure electric vehicle or the hybrid electric vehicle has the greatest advantages of saving energy and recycling braking energy in the braking process, thereby improving the energy utilization rate. The recovery of the braking energy means that the vehicle releases the braking energy in the braking process of the vehicle, and the braking energy released by the vehicle is transferred to a power battery in the vehicle through a motor. Therefore, there is a need to determine the efficiency of recovery of braking energy during braking of a vehicle.

In the related art, there are mainly three methods for determining the braking energy recovery efficiency during braking of a vehicle, and the three methods include: simulation test, bench experiment test and field test.

The inventor finds in the research process that in the related art, when the recovery efficiency of the braking energy in the braking process of the vehicle is determined, the determined recovery efficiency of the vehicle in the braking process has a large deviation from the actual recovery efficiency of the vehicle, so that the accuracy of the determined recovery efficiency of the vehicle in the braking process is low, and finally, the evaluation result is influenced when the vehicle is evaluated according to the recovery efficiency of the braking energy.

Disclosure of Invention

The embodiment of the invention provides a method, a device and a system for determining the braking energy recovery efficiency of an automobile, which can improve the accuracy of determining the braking energy recovery efficiency of a tested vehicle in the braking process.

In a first aspect, a method for determining the recovery efficiency of automobile braking energy is provided, where the method for determining the recovery efficiency of automobile braking energy includes:

acquiring first braking state information of a test vehicle, wherein the first braking state information comprises the speed of the test vehicle in the braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle;

and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Optionally, the first braking state information further includes: the wheel speed of the test vehicle during braking and the moment of inertia of the wheels of the test vehicle.

Optionally, the determining, according to the first braking state information of the test vehicle, the braking energy recovery efficiency of the test vehicle in the braking process includes:

determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of a motor controller in the test vehicle and the current of the motor controller;

determining the braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle;

determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotational speed of the wheels;

according to the vehicle speed, determining resistance energy consumed by the resistance of the test vehicle in the braking process;

and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotation kinetic energy and the resistance energy.

Optionally, the determining, according to the voltage of the motor controller in the test vehicle and the current of the motor controller, the regenerative electric energy generated by the test vehicle during braking includes:

screening the current of the motor controller according to a preset condition to obtain screened current;

determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the screening current;

the determining the braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle comprises:

determining the initial speed of the test vehicle when the test vehicle starts to brake and the final speed of the test vehicle after the brake is finished according to the vehicle speed, the acceleration of the test vehicle and the brake time of the test vehicle;

determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the test vehicle starts to brake, the final speed of the test vehicle after the braking is finished and the mass of the test vehicle;

the determining the rotational kinetic energy of the wheel of the test vehicle in the braking process according to the rotational inertia of the wheel of the test vehicle and the wheel rotating speed comprises the following steps:

carrying out first filtering processing on the wheel rotating speed to obtain a filtered wheel rotating speed after first filtering;

determining the kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotating speed of the filtering wheels;

the determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the vehicle speed comprises the following steps:

carrying out second filtering processing on the vehicle speed to obtain a filtered vehicle speed after second filtering;

obtaining a sliding coefficient of the test vehicle in a braking process;

determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient;

optionally, the determining the feedback electric energy generated by the test vehicle during the braking process according to the voltage of the controller and the screening current comprises:

E_{go back to}＝∫UIdt

Wherein E is_{Go back to}Representing feedback electric energy generated by the test vehicle in the braking process, U representing the voltage of the motor controller, I representing the screening current, and t representing the braking time of the test vehicle;

the determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the test vehicle starts braking, the final speed of the test vehicle after braking is finished and the mass of the test vehicle comprises:

wherein E is_{System for making}Representing the braking kinetic energy of the test vehicle during braking, and m represents the mass of the test vehicle; v1 represents the initial speed of the test vehicle at the beginning of braking, v2 represents the final speed of the test vehicle after braking is finished;

determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the filtering wheel rotating speed, and the method comprises the following steps:

wherein E is_{Rotating shaft}Representing the rotational kinetic energy of the wheels of the test vehicle during braking, J representing the rotational inertia, and n representing the rotational speed of the filtered wheels;

the step of determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient comprises the following steps:

E_{resistance device}＝∫3.6×10⁶×v×(A+Bv+Cv²)dt

Wherein E is_{Resistance device}Representing resistance energy consumed by the resistance of the test vehicle during braking, and v representing the filtering vehicle speed; t represents the braking time of the test vehicle, and A, B and C respectively represent different slip coefficients of the test vehicle;

the determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotation kinetic energy and the resistance energy comprises the following steps:

or

And eta represents the braking energy recovery efficiency of the test vehicle in the braking process.

Optionally, before the obtaining the first braking state information of the test vehicle, the method for determining the automobile braking energy recovery efficiency further includes:

acquiring state information of the test vehicle under a preset working condition, wherein the preset working condition is information which needs to be predetermined before the test vehicle is braked;

and taking the state information of the test vehicle under the preset working condition as the braking state information of the test vehicle.

Optionally, after determining the braking energy recovery efficiency of the test vehicle in the braking process, the method for determining the braking energy recovery efficiency of the vehicle further includes:

evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process;

the evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process comprises the following steps:

acquiring preset braking energy recovery efficiency of the test vehicle;

and evaluating the performance of the test vehicle according to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process.

In a second aspect, an automobile braking energy recovery efficiency determination device is provided, which includes:

the system comprises a first acquisition module, a second acquisition module and a control module, wherein the first acquisition module is used for acquiring first braking state information of a test vehicle, and the braking state information comprises the speed of the test vehicle in the braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle;

and the determining module is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Optionally, the determining module includes:

the first determining unit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of a motor controller in the test vehicle and the current of the motor controller;

the second determining unit is used for determining the braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle;

the third determining unit is used for determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the vehicle speed;

the fourth determining unit is used for determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the vehicle speed;

and the fifth determining unit is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotating kinetic energy and the resistance energy.

Optionally, the first determining unit includes:

the screening subunit is used for screening the current of the motor controller according to preset conditions to obtain screened current;

the first determining subunit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the screening current;

the second determination unit includes:

the second determining subunit is used for determining the initial speed of the test vehicle when the test vehicle starts to brake and the final speed of the test vehicle after the brake is finished according to the vehicle speed, the acceleration of the test vehicle and the brake time of the test vehicle;

the third determining subunit is used for determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the test vehicle starts to brake, the final speed of the test vehicle after the brake is finished and the mass of the test vehicle;

the third determination unit includes:

the first filtering subunit is used for performing first filtering processing on the wheel rotating speed to obtain a filtered wheel rotating speed after the first filtering;

the fourth determining subunit is used for determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotating speed of the filtered wheels;

the fourth determination unit includes:

the second filtering subunit is used for performing second filtering processing on the vehicle speed to obtain a filtered vehicle speed after the second filtering;

the obtaining subunit is used for obtaining the sliding coefficient of the test vehicle in the braking process;

and the fifth determining subunit is used for determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient.

Optionally, the first determining subunit is further configured to:

E_{go back to}＝∫UIdt

the third determining subunit is further configured to:

wherein E is_{System for making}Representing the braking kinetic energy of the test vehicle during braking, and m represents the mass of the test vehicle; v1 denotes the test vehicle at the beginning of brakingV2 represents the final speed of the test vehicle after braking is finished;

the fourth determining subunit is further configured to:

the fifth determining subunit is further configured to:

E_{resistance device}＝∫3.6×10⁶×v×(A+Bv+Cv²)dt

the fifth determination unit is configured to:

or

Optionally, the device for determining the braking energy recovery efficiency of the automobile further includes:

the second acquisition module is used for acquiring the state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information which needs to be predetermined before the test vehicle is braked;

the evaluation module is used for evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process;

the evaluation module is configured to:

acquiring preset braking energy recovery efficiency of the test vehicle;

In a third aspect, an apparatus for determining the recovery efficiency of automobile braking energy is provided, where the apparatus includes:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of any of the above methods of the first aspect.

In a fourth aspect, a computer-readable storage medium is provided, having instructions stored thereon, which when executed by a processor, implement the steps of the method of any of the first aspect above.

In a fifth aspect, an automobile braking energy recovery efficiency determination system is provided, and the automobile braking energy recovery efficiency determination system comprises an upper computer, a data acquisition unit and a test vehicle;

the data collector is used for collecting first braking state information of the test vehicle, the upper computer is electrically connected with the data collector and is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the state information collected by the data collector.

The technical scheme provided by the invention at least has the following beneficial effects:

in the embodiment of the invention, by acquiring the braking state information of the test vehicle, the braking state information can comprise the speed of the test vehicle in the braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the quality of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle, and the braking energy recovery efficiency of the test vehicle in the braking process is determined according to the braking state information of the test vehicle. In the embodiment of the invention, the accuracy of the braking energy recovery efficiency of the test vehicle in the braking process can be more accurately determined by acquiring the voltage and the current of the motor controller of the test vehicle in the braking process and determining the braking energy recovery efficiency by combining other data, and the accuracy of the evaluation result is improved when the vehicle is evaluated according to the braking energy recovery efficiency.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

FIG. 1 is a schematic diagram of an embodiment of the present invention for testing the power output path of a power battery in a vehicle;

FIG. 2 is a flowchart of a method for determining the recovery efficiency of braking energy of an automobile according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a NEDC cycle provided by an embodiment of the present invention;

FIG. 4 is a test plot taken when the test vehicle is traveling according to the NEDC cycle of FIG. 3;

FIG. 5 is a schematic diagram of an apparatus for determining braking energy recovery efficiency of an automobile according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of an apparatus for determining braking energy recovery efficiency of an automobile according to an embodiment of the present invention;

FIG. 7 is a schematic diagram of a system for determining the recovery efficiency of braking energy of an automobile according to an embodiment of the present invention.

Reference numerals:

1: an upper computer; 2: a data acquisition unit; 3: testing the vehicle; 4: a vehicle diagnostic interface.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Before explaining the method for determining the automobile braking energy recovery efficiency provided by the embodiment of the invention, an application scenario of the embodiment of the invention is specifically explained: in the related technology, when the automobile braking energy recovery efficiency is determined, the state information of the test vehicle in the braking process is firstly acquired, and then the braking energy recovery efficiency of the test vehicle in the braking process is determined according to the state information of the test vehicle in the braking process. The state information comprises the speed of the test vehicle in the braking process, the voltage at two ends of a power battery in the test vehicle, the current at two ends of the power battery, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle.

As shown in fig. 1, the electric power in the power battery in the test vehicle can be output through three paths, the first: the electric power of the power battery is transmitted to the electric accessories in the test vehicle via the DC/DC converter. A second bar: the electric power of the power battery is transmitted to the motor through the motor controller so that the motor drives the test vehicle. And a third: the electric power of the power battery is transmitted to the vehicle-mounted air conditioner through the A/C converter. The DC/DC converter is a converter for converting a fixed DC voltage into a variable DC voltage. DC is Direct Current, namely Direct Current, and A/C is Air Conditioning, namely Air Conditioning.

During the braking process of the test vehicle, since the power battery supplies power to the electric accessories and the vehicle-mounted air conditioner in addition to the motor, acquiring the voltage and current across the power battery to determine the braking energy recovery efficiency may not be accurate. In addition, during braking of the test vehicle, kinetic energy of the wheels of the test vehicle due to rotation may also be converted into electrical energy to be stored in the power battery, and in the related art, the portion of energy is not considered, and thus, the braking energy recovery efficiency determined according to the related art may be inaccurate. The method for determining the automobile braking energy recovery efficiency provided by the embodiment of the invention is applied to the scene.

Fig. 2 is a flowchart of a method for determining the braking energy recovery efficiency of an automobile according to an embodiment of the present invention. As shown in fig. 1, the method comprises the steps of:

step 101: first braking state information of the test vehicle is acquired.

The first braking state information comprises the speed of the test vehicle in the braking process, the voltage of a motor controller of the test vehicle, the current of the motor controller, the mass of the test vehicle, the acceleration of the test vehicle and the braking time of the test vehicle.

It should be noted that, since the acceleration of the test vehicle during braking of the test vehicle is obtained, the value of the acceleration may be a negative value.

In addition, the braking state information of the test vehicle may be stored in advance by the operator, or may be obtained in real time when the test vehicle is tested, and the embodiment of the present invention is not limited herein.

It should be noted that, in the embodiment of the present invention, the power battery is connected to the motor controller, and the motor controller is connected to the motor. In the braking process of the test vehicle, the motor can generate electric power, and the electric power is transmitted to the power battery through the motor controller, so that the voltage of the motor controller and the current of the motor controller are obtained, and the electric energy input into the power battery by the test vehicle in the braking process can be accurately determined.

The motor controlled by the motor controller is a motor for driving the test vehicle to move, namely the motor controller controls a driving motor in the test vehicle. When the test vehicle is a pure electric vehicle, the test vehicle comprises a driving motor, and the motor controlled by the motor controller is the driving motor at the moment. When the test vehicle is a hybrid vehicle, the test vehicle includes a drive motor and a generator, and at this time, the motor controlled by the motor controller is the drive motor and the generator. The Generator may be a BSG (Belt Driven Starter Generator) motor.

In addition, during the test of the test vehicle, the acceleration of the test vehicle may be determined according to the braking depth of the brake pedal in the test vehicle. The braking depth of the brake pedal refers to the distance between the current position of the brake pedal and the initial position of the brake pedal. The initial position of the brake pedal is a position at which the brake pedal is not depressed, and the current position of the brake pedal is a position at which the brake pedal is depressed.

Specifically, the acceleration of the test vehicle may be determined from the correspondence between the braking depth and the acceleration of the brake pedal. The correspondence between the braking depth and the acceleration of the brake pedal may be: when the braking depth of the brake pedal is in a first range, the first range corresponds to one acceleration value, and when the braking depth of the brake pedal is in a second range, the second range corresponds to another acceleration value.

For example, table 1 shows a corresponding relationship between the braking depth and the acceleration of a brake pedal according to an embodiment of the present invention. As shown in Table 1, when the braking depth of the brake pedal is between 0.5 and 0.8cm, the corresponding acceleration value is-0.85 m/s². When the braking depth of the brake pedal is between 0.8 and 1cm, the corresponding acceleration value is-1 m/s²。

TABLE 1

Brake depth range (cm) of brake pedal	Testing acceleration (m/s) of a vehicle²)
		0.5-0.8	-0.85
0.8-1	-1

In addition, in the embodiment of the present invention, the mass of the test vehicle refers to the sum of the prepared mass of the test vehicle and 100 kilograms, that is, the mass of the test vehicle is equal to the prepared mass of the test vehicle plus 100 kilograms. The quality of the test vehicle is the weight of the test vehicle after being completely equipped (such as complete installation of spare tires, tools and the like) according to factory technical conditions and filled with various kinds of oil and water.

In addition, in order to facilitate the comparison between the method for determining the recovery efficiency of the automobile braking energy provided by the embodiment of the present invention, before step 101, the method for determining the recovery efficiency of the automobile braking energy may further include: the method comprises the steps of obtaining state information of a test vehicle under a preset working condition, wherein the preset working condition refers to information which needs to be determined in advance in the braking process of the test vehicle. And taking the state information of the test vehicle under the preset working condition as the braking state information of the test vehicle. The state information may include, among other things, a speed of the test vehicle during braking, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle, and a braking time of the test vehicle.

The embodiment of obtaining the state information of the test vehicle under the preset working condition may be: the test vehicle runs according to a preset working condition, and the state information of the test vehicle is collected in real time in the running process.

Furthermore, the test vehicle can run in a standard test site according to a preset working condition, and the state information of the test vehicle is collected in real time in the running process.

Of course, the acquired state information of the test vehicle can be stored after the test vehicle runs according to the preset working condition, and the stored state information can be directly acquired when the automobile braking energy recovery efficiency needs to be determined.

It should be noted that the preset condition may be defined according to a standard test cycle specified by an industry standard or a national standard. For example, the predetermined operating conditions may be in accordance with NEDC (New european Driving Cycle, NEDC, New european vehicle legislation Cycle). It can also be according to WLTC (Worldwide Light-duty Test Cycle). Of course, the preset operating condition may also be according to other operating conditions, and the embodiment of the present invention is not limited herein.

For example, fig. 3 is a schematic diagram of a NEDC cycle provided by an embodiment of the present invention. As shown in fig. 3, the preset conditions are defined by cycling through NEDC. Among these, NEDC was consistent with the test cycle specified in GB 18352.5. In fig. 3, the cycle can be divided into two major parts, a first part being (r) and a second part being (r). Wherein, the first is urban circulation, the second is suburban circulation, and the third is urban circulation subunit. As shown in fig. 3, during the entire cycle, the vehicle undergoes acceleration, uniform velocity, deceleration, re-acceleration, re-uniform velocity, and re-deceleration, thus continuing the cycle. In addition, as can be seen from fig. 3, in the NEDC cycle, there are 8 braking processes of the vehicle, that is, there are 8 deceleration processes of the vehicle, which are: (1) the vehicle speed is 15 km/h-0 km/h, and the acceleration is-0.83 m/s². (2) The vehicle speed is 32 km/h-0 km/h, and the acceleration is-0.81 m/s². (3) The vehicle speed is 50 km/h-35 km/h, and the acceleration is-0.52 m/s². (4) The vehicle speed is 35 km/h-0 km/h, and the acceleration is-0.97 m/s². (5) The vehicle speed is 70 km/h-50 km/h, and the acceleration is-0.69 m/s². (6) The vehicle speed is 120 km/h-80 km/h, and the acceleration is-0.69 m/s². (7) The vehicle speed is 80 km/h-50 km/h, and the acceleration is-1.04 m/s². (8) The vehicle speed is 50 km/h-0 km/h, and the acceleration is-1.39 m/s²。

Because the braking process is more, the 8 braking processes can be combined and simplified according to the continuity and the acceleration in the braking process, and the following 3 braking processes are obtained: (1) the vehicle speed is 30 km/h-10km/h and an acceleration of-0.8 m/s². (2) The vehicle speed is 80 km/h-10 km/h, and the acceleration is-1.2 m/s². (3) The vehicle speed is 120 km/h-10 km/h, and the acceleration is-0.7 m/s². That is, the preset operating condition may be the 3 braking processes described above.

In the embodiment of the present invention, the acceleration may also be referred to as a braking strength.

In addition, since the SOC (state of charge) of the power battery of the test vehicle may affect the braking energy recovery efficiency, in the embodiment of the present invention, under the condition that the test vehicle is according to the preset working condition, it may be determined that the power battery is in different SOC states, and the first braking state information of the test vehicle may be acquired. The SOC of the power battery refers to a state of charge, which may be referred to as a remaining capacity, and indicates the capability of the power battery to continue operating.

In addition, during the test, in order to complete the whole test process, in some embodiments, the test vehicle can also be tested according to different gears. For example, the test vehicle may be in a driving gear, i.e., a forward gear, during braking, when braking is performed. The test vehicle can also be in neutral during braking, and braking is carried out at the moment.

For example, 3 vehicle speeds and 3 accelerations after simplified combination in FIG. 3, i.e., a vehicle speed of 30km/h to 10km/h, an acceleration of-0.8 m/s²(ii) a The vehicle speed is 80 km/h-10 km/h, and the acceleration is-1.2 m/s²(ii) a The vehicle speed is 120 km/h-10 km/h, and the acceleration is-0.7 m/s². The gears of the test vehicle during braking may be forward and neutral. The SOC of the power cell in the test vehicle may be 90%, 60% and 30%, respectively.

At this time, when the power battery in the test vehicle is 90%, the test vehicle can run according to the following 6 conditions:

(1) the SOC of a power battery of a test vehicle is 90 +/-5 percent, the test vehicle is accelerated to (30 +/-2) km/h, after the test vehicle stably runs for 5s, the test vehicle is put into neutral, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (0.8 +/-0.05) m/s²Until the speed of the test vehicle is zero.

(2) The SOC of a power battery of a test vehicle is 90% +/-5%, the test vehicle is accelerated to 30 +/-2 km/h, after the test vehicle runs for 5s stably, a forward gear is engaged, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (0.8 +/-0.05) m/s²Until the speed of the test vehicle is zero.

(3) The SOC of a power battery of a test vehicle is 90 +/-5 percent, the test vehicle is accelerated to 80 +/-2 km/h, after the test vehicle stably runs for 5s, the neutral position is firstly hung, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (1.2 +/-0.05) m/s²Until the speed of the test vehicle is zero.

(4) The SOC of a power battery of a test vehicle is 90% +/-5%, the test vehicle is accelerated to 80 +/-2 km/h, after the test vehicle runs for 5s stably, a forward gear is engaged, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (1.2 +/-0.05) m/s²Until the speed of the test vehicle is zero.

(5) The SOC of a power battery of a test vehicle is 90 +/-5 percent, the test vehicle is accelerated to 120 +/-2 km/h, after the test vehicle stably runs for 5s, the neutral position is firstly hung, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (0.7 +/-0.05) m/s²Until the speed of the test vehicle is zero.

(6) The SOC of a power battery of a test vehicle is 90% +/-5%, the test vehicle is accelerated to 120 +/-2 km/h, after the test vehicle runs for 5s stably, a forward gear is engaged, then a brake pedal is stepped on, and the acceleration of the whole vehicle is controlled to be- (0.7 +/-0.05) m/s²Until the speed of the test vehicle is zero.

And (3) driving the power battery in the test vehicle according to the condition 6, and acquiring first braking state information of the test vehicle during the driving process of the test vehicle.

When the SOC of the power battery of the test vehicle is 90%, the test vehicle can obtain 6 pieces of state information of the test vehicle by running in the above 6 cases.

In addition, during the test of the test vehicle, the preset working condition can also be other working conditions, for example, the SOC of the power battery of the test vehicle is 20%, 40%, 60% and 80%, respectively. The vehicle speed may be 40km/h to 20km/h, and the acceleration is-0.85 m/s²(ii) a The vehicle speed is 90 km/h-20 km/h, and the acceleration is-1.4 m/s²(ii) a The vehicle speed is 130 km/h-20 km/h, and the acceleration is-0.6 m/s². The gear of the test vehicle during braking may be neutral. The embodiments of the present invention are not limited herein.

Step 102: and determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

In some embodiments, the first braking state information may further include a wheel rotation speed of the test vehicle during braking and a rotational inertia of a wheel of the test vehicle

It should be noted that before the test vehicle is tested, the rotational inertia of the wheel of the test vehicle may be obtained through a rotational inertia experiment. The moment of inertia of the wheel of the test vehicle can also be obtained by calculation, which can be specifically expressed as follows:

in the above formula, J is the moment of inertia of the wheel of the test vehicle, R₁For testing the internal diameter of the wheels of vehicles, R₂To test the outer diameter of the wheel of a vehicle.

At this time, the implementation manner of step 102 may be: determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller, wherein the feedback electric energy is the electric energy input to a power battery in the vehicle to be tested in the braking process of the vehicle to be tested; determining the braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, wherein the braking kinetic energy refers to the energy generated by the test vehicle in the braking process; determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the speed of the wheels of the test vehicle; determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the vehicle speed; and determining the recovery efficiency of the braking energy of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotation kinetic energy and the resistance energy.

The implementation mode of determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller and the current of the motor controller in the test vehicle can be as follows: screening the current of the motor controller according to a preset condition to obtain screened current; and determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage and the screening current of the motor controller in the test vehicle.

It should be noted that, during the braking process of the test vehicle, the brake system in the test vehicle charges the power battery, and the power battery also supplies power to the motor, the electrical accessories and the like in the test vehicle, and since the motor controller is connected with the power battery, when the brake system charges the power battery, the current flows to the power battery through the motor controller, and when the power battery supplies power to the motor, the electrical accessories and the like in the test vehicle, the current also flows through the motor controller. Since the direction of current is opposite when the power battery is charged and when the power battery supplies power to the outside, and the brake system in the test vehicle charges the power battery in the braking process of the test vehicle, in order to accurately determine the recovery efficiency, the current when the brake system charges the power battery in the braking process needs to be determined, and the current when the power battery supplies power to the outside does not need to be determined. However, since the direction of the current for charging the power battery is opposite to the direction of the current for supplying power to the power battery, and the current passes through the motor controller, the current of the motor controller needs to be screened.

The current direction for charging the power battery is opposite to the current direction for supplying power to the power battery, when the current direction for supplying power to the power battery is specified to be a positive direction, the current direction for charging the power battery is a negative direction, and in the braking process, the current value of the motor controller with the positive current direction is represented as a positive value, and the current value with the negative current direction is represented as a negative value. In this case, in order to determine the current for charging the power battery, the preset condition may be that the current value is smaller than zero, that is, the current value of the motor controller greater than zero is rejected, and only the current value of the motor controller smaller than zero is obtained.

For example, fig. 4 is a test graph obtained when the test vehicle runs in accordance with the NEDC cycle in fig. 3. As shown in fig. 4, the test curve of the current of the motor controller is divided into 4 parts, namely, a 1 st part, a 2 nd part, a 3 rd part and a 4 th part, wherein the current value of the 1 st part, the current value of the 2 nd part and the current value of the 4 th part are all larger than zero, and the current value of the 3 rd part is smaller than zero. And according to the preset condition that the current value is less than zero, eliminating the current value of the 1 st part, the current value of the 2 nd part and the current value of the 4 th part, and only keeping the current value of the 3 rd part. Also, as shown in fig. 4, the voltage of the motor controller is also continuously varied.

When the current direction for supplying power to the outside by the power battery is specified to be a negative direction, the current direction for charging the power battery is a positive direction, and at this time, during braking, the current value of the motor controller with the positive current direction is represented as a positive value, and the current value with the negative current direction is represented as a negative value. In this case, in order to determine the current for charging the power battery, the preset condition may be that the current value is greater than 0, that is, the current value of the motor controller smaller than 0 is eliminated, and only the current value of the motor controller greater than 0 is obtained.

The implementation mode of determining the feedback electric energy generated by the test vehicle in the braking process can be shown as the following formula according to the voltage of the motor controller in the test vehicle and the current after screening:

E_{go back to}＝∫UIdt

In the above formula, U represents the voltage of the motor controller during braking of the test vehicle; i represents the screening current of the tested vehicle in the braking process after the motor controller screens according to the preset conditions; e_{Go back to}Represents the regenerative electric energy generated by the test vehicle during the braking process, and t represents the braking time of the test vehicle.

In addition, according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, the implementation mode of determining the braking kinetic energy of the test vehicle in the braking process can be as follows: determining the initial speed of the test vehicle when the test vehicle starts to brake and the final speed of the test vehicle after the brake is finished according to the vehicle speed, the acceleration of the test vehicle and the brake time of the test vehicle; and determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the test vehicle starts to brake, the final speed of the test vehicle after the braking is finished and the mass of the test vehicle.

The implementation mode of determining the initial speed of the test vehicle when the test vehicle starts braking and the final speed of the test vehicle after braking is finished according to the vehicle speed, the acceleration of the test vehicle and the braking time of the test vehicle can be as follows: taking an initial speed value in the vehicle speed as an initial speed of the test vehicle when the test vehicle starts to brake; and determining the final speed of the test vehicle after the braking is finished according to the initial speed of the test vehicle when the braking is started, the acceleration of the test vehicle and the braking time of the test vehicle.

In some embodiments, the determination of the final speed of the test vehicle after the braking is finished may be performed according to the initial speed of the test vehicle when the braking is started, the acceleration of the test vehicle, and the braking time of the test vehicle as follows:

v₂＝v₁+at

in the above formula, v₁Representing the initial velocity of the test vehicle at the onset of braking, a representing the acceleration of the test vehicle, v₂Represents the final speed of the test vehicle after the braking is finished, and t represents the braking time.

In some embodiments, the implementation of determining the braking kinetic energy of the test vehicle during braking may be as follows according to the initial speed of the test vehicle at the beginning of braking, the final speed of the test vehicle after the end of braking, and the mass of the test vehicle:

in the above formula, E_{System for making}Representing the braking kinetic energy of the test vehicle during the braking process; m represents the mass of the test vehicle, which may be a testAdding 100kg of the servicing mass of the vehicle; v. of₁Representing the initial speed of the test vehicle at the beginning of braking; v. of₂Indicating the final speed of the test vehicle after braking has ended.

In addition, according to the moment of inertia of the wheel of the test vehicle and the wheel rotation speed, the implementation mode of determining the rotational kinetic energy of the wheel of the test vehicle in the braking process can be as follows: carrying out first filtering processing on the wheel rotating speed to obtain a filtered wheel rotating speed after the first filtering; and determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia of the wheels of the test vehicle and the rotating speed of the filtering wheels.

In the process of testing vehicle braking, when the wheel rotating speed of the test vehicle is obtained, deviation occurs in the obtained test of the test vehicle due to signal interference or the influence of sampling frequency, in order to avoid the situation, first filtering processing is carried out on the wheel rotating speed of the test vehicle in the braking process, and the filtered wheel rotating speed after the first filtering is obtained. The first filtering process may be to digitally filter the wheel rotation speed of the test vehicle during braking. Of course, the first filtering process may also perform other filtering processes on the wheel rotation speed, such as kalman filtering, and the first filtering process is not limited in the embodiment of the present invention.

The implementation manner of determining the kinetic energy of the wheel of the test vehicle in the braking process according to the rotational inertia of the wheel of the test vehicle and the wheel rotating speed after the first filtering can be shown as follows:

in the above formula, E_{Rotating shaft}Representing the rotational kinetic energy of the wheels of the test vehicle during braking, J representing the rotational inertia of the wheels of the test vehicle, and n representing the filtered wheel speed after the first filtering.

According to the vehicle speed, the implementation mode of determining the resistance energy consumed by the resistance of the test vehicle in the braking process can be as follows: carrying out second filtering processing on the vehicle speed to obtain a filtered vehicle speed after second filtering; obtaining a sliding coefficient of a test vehicle in a braking process; and determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient.

In the process of testing vehicle braking, when the vehicle speed of the test vehicle is obtained, deviation occurs in the obtained test of the test vehicle due to signal interference or the influence of sampling frequency, and in order to avoid the deviation, second filtering processing is carried out on the vehicle speed of the test vehicle in the braking process, so that the filtered vehicle speed after the second filtering is obtained. The second filtering process may be to digitally filter the vehicle speed of the test vehicle during braking. Of course, the second filtering process may also perform other filtering processes on the vehicle speed, such as kalman filtering, and the second filtering process is not limited in the embodiment of the present invention.

In some embodiments, the implementation of determining the energy consumed by the resistance of the test vehicle during braking according to the filtered vehicle speed and the filtered slip coefficient may be as follows:

E_{resistance device}＝∫3.6×10⁶×v×(A+Bv+Cv²)dt

In the above formula, E_{Resistance device}Resistance energy representing resistance consumption of the test vehicle during braking; v represents the filtered vehicle speed after the second filtering; t represents the braking time of the test vehicle, and A, B and C represent different slip coefficients of the test vehicle, respectively.

In addition, according to the feedback electric energy, the braking kinetic energy, the rotational kinetic energy and the resistance energy, the implementation mode for determining the braking energy recovery efficiency of the test vehicle in the braking process can be shown as the following formula:

in the above formula, η represents the braking energy recovery efficiency of the test vehicle in the braking process; e_{Go back to}Representing the regenerative electric energy generated during the braking of the test vehicle; e_{System for making}Representing the braking kinetic energy of the test vehicle during the braking process; e_{Rotating shaft}Representing the kinetic energy of the wheels of the test vehicle during braking; e_{Resistance device}Indicating test vehicleThe energy consumed by the resistance of the vehicle during braking.

Wherein, the above formula can also be expressed as:

in the above formula, U represents the voltage of the motor controller during the test vehicle braking process; i represents the current of the motor controller after the braking process of the test vehicle is screened according to preset conditions; t represents the braking time of the test vehicle; m represents the mass of the test vehicle, which may be the prepared mass of the test vehicle plus 100 kilograms; v. of₁Representing the initial speed of the test vehicle at the beginning of braking; v. of₂Representing the final speed of the test vehicle after the braking is finished; j denotes the moment of inertia of the wheel of the test vehicle and n denotes the wheel speed of the test vehicle during braking.

It should be noted that, when the braking energy recovery efficiency of the test vehicle in the braking process is determined according to the above formula, if the test vehicle includes a plurality of motors, and each motor is connected with one motor controller, a plurality of voltages and a plurality of currents at two ends of the plurality of motor controllers are obtained, at this time, the voltages and the currents at two ends of each motor controller can be brought into the above formula to determine one braking energy recovery efficiency, and then each braking energy recovery efficiency is added to obtain a total braking energy recovery efficiency, and the total braking energy recovery efficiency is used as the braking energy recovery efficiency of the test vehicle in the braking process.

For example, the test vehicle includes a first motor, a second motor and a third motor, the first motor is connected to the first motor controller, the second motor is connected to the second motor controller, and the third motor is connected to the third motor controller, so that the voltage and current of the first motor controller, the voltage and current of the second motor, and the voltage and current of the third motor can be obtained And adding the second recovery efficiency and the third recovery efficiency to obtain a sum which is used as the braking energy recovery efficiency of the test vehicle in the braking process.

In addition, for evaluating the test vehicle, in some embodiments, after determining the braking energy recovery efficiency of the test vehicle during braking, the method for determining the braking energy recovery efficiency of the automobile may further include: and evaluating the performance of the test vehicle according to the braking energy recovery efficiency of the test vehicle in the braking process.

According to the braking energy recovery efficiency of the test vehicle in the braking process, the implementation mode of evaluating the performance of the test vehicle can be as follows: and acquiring the preset braking energy recovery efficiency of the test vehicle, and evaluating the performance of the test vehicle according to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process.

According to the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process, the implementation mode of evaluating the performance of the test vehicle can be as follows: the method comprises the steps of comparing preset braking energy recovery efficiency with braking energy recovery efficiency of a test vehicle in a braking process, when the difference between the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process is smaller than or equal to a numerical threshold, indicating that the performance of the test vehicle is good, and when the difference between the preset braking energy recovery efficiency and the braking energy recovery efficiency of the test vehicle in the braking process is larger than the numerical threshold, indicating that the performance of the test vehicle is poor, and detecting the test vehicle.

For example, the preset braking energy recovery efficiency of the test vehicle is 20%, and the numerical threshold is 1%. When the braking energy recovery efficiency of the test vehicle in the braking process is 18%, the difference between the preset braking energy recovery efficiency of the test vehicle of 20% and the braking energy recovery efficiency of the test vehicle of 18% in the braking process is 2% and more than 1%, which indicates that the performance of the test vehicle is poor and the test vehicle needs to be detected. When the braking energy recovery efficiency of the test vehicle in the braking process is 19%, the difference value between the preset braking energy recovery efficiency of the test vehicle of 20% and the braking energy recovery efficiency of the test vehicle of 19% in the braking process is 2% and is equal to 1%, which indicates that the performance of the test vehicle is good and the test vehicle does not need to be detected.

In addition, according to the braking energy recovery efficiency of the test vehicle in the braking process, the implementation mode of evaluating the performance of the test vehicle can also be as follows: the method comprises the steps of obtaining the braking energy recovery efficiency of a plurality of test vehicles in the braking process, comparing the braking energy recovery efficiency of the plurality of test vehicles in the braking process, and obtaining the best performance of the test vehicle corresponding to the maximum braking energy recovery efficiency in a plurality of braking energy recovery efficiency values.

It should be noted that when the braking energy recovery efficiency of a plurality of test vehicles in the braking process is obtained, the plurality of test vehicles can all run and brake under the same preset working condition. For example, 3 test vehicles are obtained to run and brake under the same preset working condition, which may be: the SOC of the power battery is 60 percent, and the acceleration is-0.8 m/s². The 3 test vehicles are respectively a test vehicle A, a test vehicle B and a test vehicle C, the braking energy recovery efficiency of the test vehicle A is 35%, the braking energy recovery efficiency of the test vehicle B is 40%, and the braking energy recovery efficiency of the test vehicle C is 30%. After comparison, the test vehicle B had the greatest efficiency in recovering braking energy, indicating that the test vehicle B performed the best of the 3 test vehicles.

In the embodiment of the invention, by acquiring the braking state information of the test vehicle, the braking state information may include the speed of the test vehicle during braking, the rotational speed of the wheel, the voltage of a motor controller in the test vehicle, the current of the motor controller, the rotational inertia of the wheel of the test vehicle, the mass of the test vehicle, the acceleration of the test vehicle, and the braking time of the test vehicle. And determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in the embodiment of the present inventionIn (1),by obtaining the voltage and current of the motor controller of the test vehicle during braking,the accuracy of the braking energy recovery efficiency of the tested vehicle in the braking process can be more accurately determined according to the voltage and the current of the motor controller and other data, and therefore the accuracy of the evaluation result is improved when the vehicle is evaluated according to the braking energy recovery efficiency.

Fig. 5 is a schematic diagram of an apparatus for determining braking energy recovery efficiency of an automobile according to an embodiment of the present invention. As shown in fig. 5, the vehicle braking energy recovery efficiency determination apparatus 500 includes:

the first obtaining module 501 is configured to obtain first braking state information of the test vehicle, where the braking state information includes a vehicle speed of the test vehicle in a braking process, a voltage of a motor controller of the test vehicle, a current of the motor controller, a mass of the test vehicle, an acceleration of the test vehicle, and a braking time of the test vehicle;

the determining module 502 is configured to determine the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle.

Optionally, the first braking state information further includes: the wheel speed of the vehicle during braking is tested and the moment of inertia of the wheels of the vehicle is tested.

Optionally, the determining module 502 comprises:

the first determining unit is used for determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller, wherein the feedback electric energy is the electric energy input to a power battery in the vehicle to be tested in the braking process of the vehicle to be tested;

the second determining unit is used for determining the braking kinetic energy of the test vehicle in the braking process according to the vehicle speed, the acceleration of the test vehicle, the mass of the test vehicle and the braking time of the test vehicle, wherein the braking kinetic energy refers to the energy generated by the test vehicle in the braking process;

the third determining unit is used for determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the vehicle speed of the wheels of the test vehicle;

and the fifth determining unit is used for determining the braking energy recovery efficiency of the test vehicle in the braking process according to the feedback electric energy, the braking kinetic energy, the rotation kinetic energy and the resistance energy.

Optionally, the first determining unit includes:

the first determining subunit is used for determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage and the screening current of the motor controller in the test vehicle.

A second determination unit comprising:

the third determining subunit is used for determining the braking kinetic energy of the test vehicle in the braking process according to the initial speed of the test vehicle when the test vehicle starts to brake, the final speed of the test vehicle after the braking is finished and the mass of the test vehicle;

a third determination unit including:

a fourth determination unit including:

and the fifth determining subunit is used for determining the resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient.

Optionally, the first determining subunit is further configured to:

E_{go back to}＝∫UIdt

Wherein E is_{Go back to}Representing the feedback electric energy generated by the test vehicle in the braking process, U representing the voltage of the motor controller, I representing the screening current, and t representing the braking time of the test vehicle;

the third determining subunit is further configured to:

wherein E is_{System for making}The braking kinetic energy of the test vehicle in the braking process is represented, and m represents the mass of the test vehicle; v1 represents the initial speed of the test vehicle when the braking is started, and v2 represents the final speed of the test vehicle after the braking is finished;

the fourth determining subunit is further configured to:

wherein E is_{Rotating shaft}Representing the rotational kinetic energy of the wheels of the test vehicle in the braking process, J representing the rotational inertia, and n representing the rotational speed of the filtering wheels;

the fifth determining subunit is further configured to:

E_{resistance device}＝∫3.6×10⁶×v×(A+Bv+Cv²)dt

Wherein E is_{Resistance device}Representing resistance energy consumed by resistance of the test vehicle in the braking process, and v represents filtering vehicle speed; t represents the braking time of the test vehicle, and A, B and C respectively represent different slip coefficients of the test vehicle;

the fifth determination unit is configured to:

or

Optionally, the apparatus 500 for determining the braking energy recovery efficiency of an automobile further includes:

the third acquisition module is used for acquiring the state information of the test vehicle under a preset working condition, wherein the preset working condition refers to information which needs to be predetermined before the test vehicle is braked;

the evaluation module is used for:

acquiring preset braking energy recovery efficiency of a test vehicle;

In the embodiment of the invention, by acquiring the braking state information of the test vehicle, the braking state information may include the speed of the test vehicle during braking, the rotational speed of the wheel, the voltage of a motor controller in the test vehicle, the current of the motor controller, the rotational inertia of the wheel of the test vehicle, the mass of the test vehicle, the acceleration of the test vehicle, and the braking time of the test vehicle. And determining the braking energy recovery efficiency of the test vehicle in the braking process according to the braking state information of the test vehicle. That is, in the embodiment of the present invention, the accuracy of the braking energy recovery efficiency of the test vehicle in the braking process can be more accurately determined by acquiring the voltage and the current of the motor controller of the test vehicle in the braking process, and determining the braking energy recovery efficiency by combining other data, so as to improve the accuracy of the evaluation result when the vehicle is evaluated according to the braking energy recovery efficiency.

It should be noted that: when the device for determining the recovery efficiency of the automobile braking energy provided by the embodiment determines the recovery efficiency of the automobile braking energy, only the division of the functional modules is taken as an example, and in practical application, the function distribution can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules so as to complete all or part of the functions described above. In addition, the embodiment of the device for determining the recovery efficiency of the automobile braking energy and the embodiment of the method for determining the recovery efficiency of the automobile braking energy provided by the embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment and is not described herein again.

Fig. 6 is a schematic diagram of an apparatus for determining braking energy recovery efficiency of an automobile according to an embodiment of the present invention. The automobile braking energy recovery efficiency determination apparatus 600 may be: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III, motion video Experts compression standard Audio Layer 3), an MP4 player (Moving Picture Experts Group Audio Layer IV, motion video Experts compression standard Audio Layer 4), a notebook computer, or a desktop computer. The automobile braking energy recovery efficiency determination apparatus 600 may also be referred to as a user device, a portable automobile braking energy recovery efficiency determination apparatus, a laptop automobile braking energy recovery efficiency determination apparatus, a desktop automobile braking energy recovery efficiency determination apparatus, or other names.

Generally, the braking energy recovery efficiency determining apparatus 600 for an automobile includes: a processor 601 and a memory 602.

The processor 601 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and so on. The processor 601 may be implemented in at least one hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 601 may also include a main processor and a coprocessor, where the main processor is a processor for Processing data in an awake state, and is also called a Central Processing Unit (CPU); a coprocessor is a low power processor for processing data in a standby state. In some embodiments, the processor 601 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the display screen. In some embodiments, processor 601 may also include an AI (Artificial Intelligence) processor for processing computational operations related to machine learning.

The memory 602 may include one or more computer-readable storage media, which may be non-transitory. The memory 602 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In some embodiments, a non-transitory computer readable storage medium in the memory 602 is configured to store at least one instruction for execution by the processor 601 to implement the method for determining the recovery efficiency of vehicle braking energy provided by the method embodiments of the present application.

In some embodiments, the apparatus 600 for determining the braking energy recovery efficiency of the vehicle may further include: a peripheral interface 603 and at least one peripheral. The processor 601, memory 602, and peripheral interface 603 may be connected by buses or signal lines. Various peripheral devices may be connected to the peripheral interface 603 via a bus, signal line, or circuit board. Specifically, the peripheral device includes: at least one of a radio frequency circuit 604, a touch screen display 605, a camera assembly 606, an audio circuit 607, a positioning component 608, and a power supply 609.

The peripheral interface 603 may be used to connect at least one peripheral related to I/O (Input/Output) to the processor 601 and the memory 602. In some embodiments, the processor 601, memory 602, and peripheral interface 603 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 601, the memory 602, and the peripheral interface 603 may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

The Radio Frequency circuit 604 is used for receiving and transmitting RF (Radio Frequency) signals, also called electromagnetic signals. The radio frequency circuitry 604 communicates with communication networks and other communication devices via electromagnetic signals. The rf circuit 604 converts an electrical signal into an electromagnetic signal to transmit, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 604 comprises: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and so forth. The radio frequency circuit 604 may communicate with other vehicle braking energy recovery efficiency determination devices via at least one wireless communication protocol. The wireless communication protocols include, but are not limited to: metropolitan area networks, various generation mobile communication networks (2G, 3G, 4G, and 5G), Wireless local area networks, and/or WiFi (Wireless Fidelity) networks. In some embodiments, the rf circuit 604 may further include NFC (Near Field Communication) related circuits, which are not limited in this application.

The display 605 is used to display a UI (User Interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display screen 605 is a touch display screen, the display screen 605 also has the ability to capture touch signals on or over the surface of the display screen 605. The touch signal may be input to the processor 601 as a control signal for processing. At this point, the display 605 may also be used to provide virtual buttons and/or a virtual keyboard, also referred to as soft buttons and/or a soft keyboard. In some embodiments, the display 605 may be one, and is provided as a front panel of the vehicle braking energy recovery efficiency determination apparatus 600; in other embodiments, the number of the display screens 605 may be at least two, and the at least two display screens are respectively disposed on different surfaces of the braking energy recovery efficiency determining apparatus 600 or are in a folding design; in still other embodiments, the display 605 may be a flexible display disposed on a curved surface or a folded surface of the vehicle braking energy recovery efficiency determining apparatus 600. Even more, the display 605 may be arranged in a non-rectangular irregular pattern, i.e., a shaped screen. The Display 605 may be made of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), and the like.

The camera assembly 606 is used to capture images or video. Optionally, camera assembly 606 includes a front camera and a rear camera. Generally, the front camera is disposed on a front panel of the vehicle braking energy recovery efficiency determination device, and the rear camera is disposed on a rear surface of the vehicle braking energy recovery efficiency determination device. In some embodiments, the number of the rear cameras is at least two, and each rear camera is any one of a main camera, a depth-of-field camera, a wide-angle camera and a telephoto camera, so that the main camera and the depth-of-field camera are fused to realize a background blurring function, and the main camera and the wide-angle camera are fused to realize panoramic shooting and VR (Virtual Reality) shooting functions or other fusion shooting functions. In some embodiments, camera assembly 606 may also include a flash. The flash lamp can be a monochrome temperature flash lamp or a bicolor temperature flash lamp. The double-color-temperature flash lamp is a combination of a warm-light flash lamp and a cold-light flash lamp, and can be used for light compensation at different color temperatures.

Audio circuitry 607 may include a microphone and a speaker. The microphone is used for collecting sound waves of a user and the environment, converting the sound waves into electric signals, and inputting the electric signals to the processor 601 for processing or inputting the electric signals to the radio frequency circuit 604 to realize voice communication. For the purpose of stereo sound collection or noise reduction, a plurality of microphones may be respectively disposed at different positions of the automobile braking energy recovery efficiency determination apparatus 600. The microphone may also be an array microphone or an omni-directional pick-up microphone. The speaker is used to convert electrical signals from the processor 601 or the radio frequency circuit 604 into sound waves. The loudspeaker can be a traditional film loudspeaker or a piezoelectric ceramic loudspeaker. When the speaker is a piezoelectric ceramic speaker, the speaker can be used for purposes such as converting an electric signal into a sound wave audible to a human being, or converting an electric signal into a sound wave inaudible to a human being to measure a distance. In some embodiments, audio circuitry 607 may also include a headphone jack.

The positioning component 608 is used for positioning the current geographic Location of the vehicle braking energy recovery efficiency determining apparatus 600 to implement navigation or LBS (Location Based Service). The Positioning component 608 can be a Positioning component based on the united states GPS (Global Positioning System), the chinese beidou System, the russian graves System, or the european union's galileo System.

The power supply 609 is used for supplying power to each component in the automobile braking energy recovery efficiency determination device 600. The power supply 609 may be ac, dc, disposable or rechargeable. When the power supply 609 includes a rechargeable battery, the rechargeable battery may support wired or wireless charging. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, the vehicle braking energy recovery efficiency determination apparatus 600 further includes one or more sensors 610. The one or more sensors 610 include, but are not limited to: acceleration sensor 611, gyro sensor 612, pressure sensor 613, fingerprint sensor 614, optical sensor 615, and proximity sensor 616.

The acceleration sensor 611 may detect the magnitude of acceleration on three coordinate axes of the coordinate system established by the vehicle braking energy recovery efficiency determining apparatus 600. For example, the acceleration sensor 611 may be used to detect components of the gravitational acceleration in three coordinate axes. The processor 601 may control the touch screen display 605 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 611. The acceleration sensor 611 may also be used for acquisition of motion data of a game or a user.

The gyroscope sensor 612 may detect a body direction and a rotation angle of the automobile braking energy recovery efficiency determination apparatus 600, and the gyroscope sensor 612 and the acceleration sensor 611 may cooperate to acquire a 3D action of the user on the automobile braking energy recovery efficiency determination apparatus 600. The processor 601 may implement the following functions according to the data collected by the gyro sensor 612: motion sensing (such as changing the UI according to a user's tilting operation), image stabilization at the time of photographing, game control, and inertial navigation.

The pressure sensor 613 may be disposed on a side frame of the vehicle braking energy recovery efficiency determining apparatus 600 and/or on a lower layer of the touch display screen 605. When the pressure sensor 613 is disposed on the side frame of the vehicle braking energy recovery efficiency determination apparatus 600, a holding signal of a user to the vehicle braking energy recovery efficiency determination apparatus 600 may be detected, and the processor 601 performs left-right hand recognition or quick operation according to the holding signal acquired by the pressure sensor 613. When the pressure sensor 613 is disposed at the lower layer of the touch display screen 605, the processor 601 controls the operability control on the UI interface according to the pressure operation of the user on the touch display screen 605. The operability control comprises at least one of a button control, a scroll bar control, an icon control and a menu control.

The fingerprint sensor 614 is used for collecting a fingerprint of a user, and the processor 601 identifies the identity of the user according to the fingerprint collected by the fingerprint sensor 614, or the fingerprint sensor 614 identifies the identity of the user according to the collected fingerprint. Upon identifying that the user's identity is a trusted identity, the processor 601 authorizes the user to perform relevant sensitive operations including unlocking the screen, viewing encrypted information, downloading software, paying, and changing settings, etc. The fingerprint sensor 614 may be disposed on the front, back, or side of the vehicle braking energy recovery efficiency determining apparatus 600. When a physical button or a manufacturer Logo is provided on the automobile braking energy recovery efficiency determination device 600, the fingerprint sensor 614 may be integrated with the physical button or the manufacturer Logo.

The optical sensor 615 is used to collect the ambient light intensity. In one embodiment, processor 601 may control the display brightness of touch display 605 based on the ambient light intensity collected by optical sensor 615. Specifically, when the ambient light intensity is high, the display brightness of the touch display screen 605 is increased; when the ambient light intensity is low, the display brightness of the touch display screen 605 is turned down. In another embodiment, the processor 601 may also dynamically adjust the shooting parameters of the camera assembly 606 according to the ambient light intensity collected by the optical sensor 615.

The proximity sensor 616, also called a distance sensor, is generally provided on the front panel of the vehicle braking energy recovery efficiency determining apparatus 600. The proximity sensor 616 is used to capture the distance between the user and the front face of the vehicle braking energy recovery efficiency determination apparatus 600. In one embodiment, when the proximity sensor 616 detects that the distance between the user and the front surface of the automobile braking energy recovery efficiency determination apparatus 600 gradually decreases, the processor 601 controls the touch display screen 605 to switch from the bright screen state to the dark screen state; when the proximity sensor 616 detects that the distance between the user and the front surface of the automobile braking energy recovery efficiency determination device 600 is gradually increased, the processor 601 controls the touch display screen 605 to switch from the screen-off state to the screen-on state.

Those skilled in the art will appreciate that the configuration shown in FIG. 6 does not constitute a limitation of the vehicle braking energy recovery efficiency determining apparatus 600, and may include more or fewer components than shown, or some components may be combined, or a different arrangement of components may be employed.

An embodiment of the present application further provides a non-transitory computer-readable storage medium, where when an instruction in the storage medium is executed by a processor of an automobile braking energy recovery efficiency determination device, the automobile braking energy recovery efficiency determination device can execute the method for determining the automobile braking energy recovery efficiency provided in the embodiment shown in fig. 1.

The embodiment of the present application further provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the method for determining the braking energy recovery efficiency of an automobile provided in the embodiment shown in fig. 1.

FIG. 7 is a schematic diagram of a system for determining the recovery efficiency of braking energy of an automobile according to an embodiment of the present invention. As shown in fig. 7, the system includes an upper computer 1, a data collector 2, and a test vehicle 3.

The data acquisition unit 2 is used for acquiring first braking state information of the test vehicle 3, the upper computer 1 is electrically connected with the data acquisition unit 2, and the upper computer 1 is used for determining the braking energy recovery efficiency of the test vehicle 3 in the braking process according to the first braking state information acquired by the data acquisition unit 2.

The data acquisition unit 2 may be a general data acquisition device, such as Vbox, RT3000, Canoe, or other special data acquisition devices. The upper computer 1 can be a mobile phone, a notebook computer, a desktop computer and the like.

In addition, as shown in fig. 7, a vehicle diagnosis interface 4 is configured on the test vehicle 3, and the data collector 2 may be connected to the vehicle diagnosis interface 4 to collect first braking state information of the test vehicle 3 during braking. And the data acquisition unit 2 is also connected with the upper computer 1, and sends the acquired first braking state information to the upper computer 1, and the upper computer 1 determines the braking energy recovery efficiency of the test vehicle 3 in the braking process according to the first braking state information.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.

While preferred embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or vehicle braking energy recovery efficiency determining apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or vehicle braking energy recovery efficiency determining apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the process, method, article, or vehicle braking energy recovery efficiency determining apparatus that comprises the element.

The technical solutions provided by the present invention are described in detail above, and the principle and the implementation of the present invention are explained in this document by applying specific examples, and the descriptions of the above examples are only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A method for determining the recovery efficiency of automobile braking energy is characterized by comprising the following steps:

2. The automotive braking energy recovery efficiency determination method of claim 1, wherein the first braking state information further includes: the wheel speed of the test vehicle during braking and the moment of inertia of the wheels of the test vehicle.

3. The method for determining automobile braking energy recovery efficiency according to claim 2, wherein the determining the braking energy recovery efficiency of the test vehicle in the braking process according to the first braking state information of the test vehicle comprises:

4. The method for determining automobile braking energy recovery efficiency according to claim 3, wherein the determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage of the motor controller in the test vehicle and the current of the motor controller comprises:

determining feedback electric energy generated by the test vehicle in the braking process according to the voltage of the controller and the screening current;

determining the rotational kinetic energy of the wheels of the test vehicle in the braking process according to the rotational inertia and the rotating speed of the filtering wheels;

obtaining a sliding coefficient of the test vehicle in a braking process;

and determining resistance energy consumed by the resistance of the test vehicle in the braking process according to the filtering vehicle speed and the sliding coefficient.

5. The method for determining automobile braking energy recovery efficiency according to claim 4, wherein the determining the feedback electric energy generated by the test vehicle in the braking process according to the voltage of the controller and the screening current comprises:

E_{go back to}＝∫UIdt

E_{resistance device}＝∫3.6×10⁶×v×(A+Bv+Cv²)dt

or

6. The automotive braking energy recovery efficiency determination method of claim 1, wherein, prior to the obtaining the first braking state information of the test vehicle, the automotive braking energy recovery efficiency determination method further comprises:

and taking the state information of the test vehicle under the preset working condition as the first braking state information of the test vehicle.

7. The automobile braking energy recovery efficiency determination method of claim 1, wherein after determining the braking energy recovery efficiency of the test vehicle during braking, the automobile braking energy recovery efficiency determination method further comprises:

acquiring preset braking energy recovery efficiency of the test vehicle;

8. An automobile braking energy recovery efficiency determining device, characterized by comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of any one of the method of claim 1 to claim 7.

9. A computer readable storage medium having stored thereon instructions which, when executed by a processor, carry out the steps of the method of any one of claims 1 to 7.

10. The automobile braking energy recovery efficiency determining system is characterized by comprising an upper computer, a data acquisition unit and a test vehicle;