CN103754204B - Electromagnetic hydraulic brake system with active pedal movement controlling function - Google Patents

Abstract

An electronic hydraulic braking system with active pedal displacement control, comprising: a brake pedal; a pedal displacement sensor; a displacement sensor for obtaining the displacement of a second electronically controlled linear motion module; a brake master cylinder, which passes through an ABS/ESP module and Hydraulic coupling of vehicle wheel brakes; the first electronically controlled linear motion module is connected to the brake master cylinder, and the motor of this module can actively control the displacement of the pedal; the second electronically controlled linear motion module is connected to the brake master cylinder, and according to the pedal The signal of the displacement sensor adjusts the hydraulic braking force of the master cylinder. The transmission mechanism of this module adopts a self-locking screw-nut mechanism; the ABS/ESP module is used to adjust the hydraulic braking force of each wheel cylinder. The system has fast response, precise control, correctly reflects the driver's braking intention, realizes the active control of hydraulic pressure, gives the driver a comfortable braking feeling by controlling the pedal displacement, and can maximize the recovery of braking energy. It can also guarantee the reliability and security of the system.

Description

An electronic hydraulic braking system with active pedal displacement control

technical field

The invention belongs to the technical field of automobiles, and relates to automobile brake technology, in particular to an electronic hydraulic brake system with pedal displacement active control.

Background technique

Due to the depletion of oil and the destruction of the environment, the advantages of energy saving and environmental protection make electric vehicles the main direction of the future development of the automobile industry. In order to improve energy utilization, save resources, and protect the environment, the automobile industry of various countries is vigorously developing electric vehicles. Due to the limitations of motor and battery technology, the two problems of short driving range and high cost of electric vehicles hinder the development of electric vehicles. popularization and commercialization.

Compound braking is usually composed of a motor braking system and a hydraulic braking system. Since the electric vehicle is equipped with a high-power drive motor, when the vehicle decelerates and brakes, the motor can be used to drag the brakes. At the same time, due to the lag of the motor during braking, the power supply is reversed to generate a reverse electromotive force, which turns the motor into a generator to generate electricity, and converts the kinetic energy of the car into electrical energy and stores it in the battery, that is, regenerative braking or braking. energy recovery. These stored electric energy can greatly increase the driving range of the car, and change the shortcomings of short driving range and large battery size of electric vehicles. Today, when the battery technology is not perfect enough, it can greatly make up for the problems caused by the lack of battery technology.

The composite braking system is mainly divided into the accelerator pedal type and the brake pedal type, and the brake pedal type is further divided into a fully decoupled composite braking system and a non-decoupled composite braking system.

The accelerator pedal composite braking system uses the accelerator pedal as the source of the braking intervention signal of the drive motor. This system has minor changes to the original braking system and is easy to control. However, it does not conform to the driver's traditional brake pedal feeling and can be recycled. The energy is also less.

The non-decoupled compound braking system generally loads a certain idle stroke on the original brake booster parts. During this idle stroke, the drive motor provides regenerative braking force. After overcoming this idle stroke, the hydraulic brake intervenes. Regenerative braking provides the total braking force together. This compound braking system retains the mechanical connection between the pedal and the hydraulic system, which has high reliability and safety, but its recyclable braking energy is less, which is different from the traditional brake pedal feel. There are deviations.

The fully decoupled composite braking system belongs to the electronic hydraulic braking system. The HAS hev system of Bosch Company and the SCB system of TRW Company belong to the fully decoupled type. There is no mechanical connection between the brake pedal and the hydraulic system. The accumulator cooperates with the motor and the pump to actively control the braking input force of the hydraulic system. It recovers a lot of braking energy and has a fast braking response. It can accurately identify the driver's braking intention and simulate the feeling of the pedal. The device technology is immature, and there are still hidden dangers in reliability and safety. In addition, the addition of multiple solenoid valves also increases the difficulty of control and the risk of failure.

In the electronic hydraulic braking system, the motor and mechanical structure are used to replace the high-pressure accumulator, pump, hydraulic pipeline and solenoid valve, and the active control and adjustment of the hydraulic pressure can also be realized. The signal is transmitted through the control circuit, and the mechanical structure is driven by the motor. Push the master cylinder, there is no hydraulic pipeline between the brake pedal and the master cylinder, and there are no problems such as hydraulic pipeline leakage, high-pressure accumulator safety hazard, solenoid valve failure, etc. Its structure is simple, and there is no need to modify the master cylinder, which reduces costs , and the reliability and safety of the mechanical connection is higher than that of the fully decoupled type. It is directly controlled by the ECU, and it is easy to realize ABS, TCS, ESP, ACC and other functions. This form of composite braking system has a bright future and is an important development direction of the future braking system.

When the motor of the main cylinder hydraulic pressure drive module adopts a self-locking transmission mechanism, the force fluctuates during self-locking, and a good control effect cannot be achieved through force control. Therefore, an electronic hydraulic system with active control of pedal displacement has been developed. The braking system, by simulating the ideal pedal force/pedal displacement relationship diagram, gives the driver an excellent pedal feel and can maximize the recovery of braking energy.

Contents of the invention

The purpose of the present invention is to provide an electronic hydraulic braking system with pedal displacement active control, the purpose is to recover more braking energy, improve the system response time, accurately identify the driver's braking intention, and realize the balance between hydraulic pressure and pedal displacement. Active control gives the driver a good braking feeling, and the mechanical connection between the brake pedal and the master cylinder ensures safety and reliability.

The purpose of the present invention can be achieved through the following technical solutions: an electronic hydraulic braking system with pedal displacement active control, comprising: a brake pedal; a pedal displacement sensor for obtaining the displacement of the brake pedal when the driver depresses it; The displacement sensor of the displacement of the second linear motion module; the brake master cylinder, which is hydraulically coupled with the wheel brake of the vehicle through the ABS/ESP module; The main cylinder is connected with the second electronically controlled linear motion module to adjust the hydraulic braking force of the master cylinder. The motor of this module can actively control the pedal displacement to simulate the feeling of the brake pedal; the second electronically controlled linear motion module, It is connected to the brake master cylinder through a connecting rod, and adjusts the hydraulic braking force of the master cylinder according to the signal of the pedal displacement sensor; ABS/ESP module, the brake master cylinder is connected to the brake master cylinder through the first and second hydraulic lines The anti-lock braking system/electronic stability control system module adjusts the hydraulic braking force of each wheel cylinder; the electronic control unit ECU receives the signals measured by the pedal displacement sensor and the hydraulic pressure sensor, and calculates the The magnitude of the hydraulic braking force and the respective motion displacements of the first and second electronically controlled linear motion modules.

Preferably, the first electronically controlled linear motion module includes an electronic control unit ECU, a motor and a linear motion mechanism, and the motor receives an adjustment torque signal sent by the electronic control unit ECU to control the linear motion mechanism.

Preferably, the second electronically controlled linear motion module includes an electronic control unit ECU, a motor and a linear motion mechanism, and the motor receives an adjustment torque signal sent by the electronic control unit ECU to control the linear motion mechanism.

Preferably, the pedal displacement sensor, the hydraulic pressure sensor, the displacement sensor, and the motors in the first and second electronically controlled linear motion modules are connected to the electronic control unit ECU through control lines to transmit signals.

Preferably, the first electronically controlled linear motion module includes a rotary motor and a transmission mechanism that converts rotary motion into linear motion, and the transmission mechanism includes a worm gear mechanism, a rack and pinion mechanism, a screw-nut mechanism or a ball screw mechanism.

Preferably, the second electronically controlled linear motion module includes a rotary motor and a transmission mechanism that converts rotary motion into linear motion. The transmission mechanism adopts a screw-nut mechanism with self-locking. When it is zero, the friction force received is not a stable value, so when the second electronically controlled linear motion module adopts this mechanism, it cannot be controlled by force, but can only be controlled by displacement. Therefore, in the second electronically controlled linear motion module A displacement sensor is added to the motion module to measure the motion displacement of the module, and cooperates with the first electronically controlled linear motion module to actively control the pedal displacement.

Compared with the existing composite braking technology, the electronic hydraulic braking system with pedal displacement active control of the present invention has the following advantages:

1. The linear motion mechanism is controlled by double-motor coordination, and the response speed is very fast. The hydraulic braking force is controlled in real time and actively adjusted, which can correctly reflect the driver's braking intention.

2. Adjust the magnitude of the hydraulic braking force according to the changing regenerative braking force of the electric vehicle drive motor to provide the total braking force, thereby maximizing the recovery of braking energy.

3. The pedal displacement is controlled by the motor of the first electronically controlled linear motion module, which ensures a good brake pedal feeling for the driver.

4. The mechanical connection between the brake pedal and the brake master cylinder reduces the risk of system failure. At the same time, the driver's pedal force is also part of the hydraulic braking force, so there is no waste of pedal force. When the first electronically controlled linear motion module or the second electronically controlled linear motion module fails, the brake pedal can still provide the required hydraulic braking force through a mechanical connection with the unfailed electronically controlled linear motion module; when the two electronically controlled linear motion modules When the linear motion module fails at the same time, the driver slams on the brake pedal, and the system can also provide a certain braking force, ensuring the reliability and safety of the vehicle braking system.

Description of drawings

FIG. 1 is a schematic diagram of an electronic hydraulic braking system with pedal displacement actively controlled according to an exemplary embodiment of the present invention.

The label in the accompanying drawing indicates:

1—Motor; 2—Stator of motor; 3—Rotor of motor; 4—First electronically controlled linear motion module; 5—Screw of ball screw; 6—Nut of ball screw; 7—Connecting rod; 8—Motor 9—motor; 10—second electronically controlled linear motion module; 11—motor stator; 12—lead screw-nut screw; 13—lead screw-nut nut; 14—pedal displacement sensor; 15—system Moving pedal; 16, 17, 18, 19, 20—control circuit; 21—hydraulic pressure sensor; 22—first piston of master cylinder; 23—fluid storage tank; 24—second piston of master cylinder; 25—brake master cylinder 26—the first working chamber of the master cylinder; 27—the second working chamber of the master cylinder; 28, 29—hydraulic pipeline; 30—ABS/ESP module; 31—electronic control unit; 32,33—linear motion mechanism; Motion detector

detailed description

As shown in Figure 1, the electronic hydraulic braking system with pedal displacement active control mainly includes a brake pedal 15, a first electronically controlled linear motion module 4, a second electronically controlled linear motion module 10, a brake master cylinder 25, a pedal displacement Sensor 14, hydraulic pressure sensor 21, displacement sensor 34

In this exemplary embodiment, the first electronically controlled linear motion module 4 includes an electronic control unit 31 , a motor 1 , and a linear motion mechanism 32 . The motor 1 is connected to the electronic control unit 31 through the control circuit 19 , and the linear motion mechanism 32 is controlled according to the motor torque signal transmitted by the electronic control unit 31 . The second electronically controlled linear motion module 10 includes an electronic control unit 31, a motor 9, and a linear motion mechanism 33. What is shown in FIG. 1 is a preferred embodiment of the first and second electronically controlled linear motion modules. The motor and the linear motion mechanism 32 are ball screw mechanisms, and the linear motion mechanism 33 is a screw-nut mechanism with self-locking. Its function is to lock the linear motion mechanism 33 when the second electronically controlled linear motion module fails, so that it Can't exercise. Brake master cylinder 25 comprises first piston 22, first working chamber 26, second piston 24, second working chamber 27, first working chamber 26 and second working chamber 27 are separated by second piston 24, and both There is a compensation hole to connect the liquid reservoir. The first working chamber 26 and the second working chamber 27 are connected to the ABS/ESP module 30 through a hydraulic pipeline 28 and a hydraulic pipeline 29 respectively. The ABS/ESP module is then connected to the four wheel side brakes through hydraulic lines. A motion regulating mechanism (not shown) is arranged between the linear motion mechanism 32 and the connecting rod 7, and its effect is to ensure that the linear motion mechanism drives the pedal push rod to perform linear motion, and the connecting rod 7 is connected with the first piston 22 to push The first piston 22 then pushes the second piston 24 to generate a desired hydraulic braking force.

The specific working process of the electro-hydraulic braking system with pedal displacement active control of the present invention is as follows: the driver depresses the brake pedal 15, the displacement sensor 14 obtains the pedal displacement, receives the driver's braking intention, and passes the collected signal through the control The line 17 is transmitted to the electronic control unit 31, and the electronic control unit 31 obtains the braking force of the driving motor during this braking, and subtracts the braking force of the driving motor from the total braking force demand to obtain the hydraulic pressure required for this braking. The magnitude of the braking force Fh, the corresponding displacement Sh of the master cylinder piston is obtained through the PV characteristic diagram of the braking system, and the displacement S2 required by the second electronically controlled linear motion module 10 (S ₂ =S _h L ₁ /L, L=L ₁ +L ₂ ), and then drive the motor 9 through the control circuit 18 to push the first piston 22 connected to the connecting rod 7 to move linearly. When the first piston 22 blocks the first compensation hole, the first working chamber starts to build up pressure, and then the Push the second piston 24 to move linearly, when the second piston 24 blocks the second compensation hole, the second working chamber starts to build up pressure, and the brake fluid flows to the ABS/ESP module 30 through the hydraulic pipeline 28 and the hydraulic pipeline 29, and then flows to each Wheel cylinders generate braking force. The hydraulic sensor 21 measures the pressure value of the hydraulic pipeline 28 and transmits the signal to the electronic control unit 31. The electronic control unit 31 calculates the actual hydraulic braking force provided to obtain the corresponding pedal displacement SP, and the first electronically controlled linear motion The displacement S1 required by the module 4 (S ₁ =S ₂ ·L ₂ /L ₁ −S _p ), the electronic control unit 31 drives the motor 1 through the control circuit 19 .

According to a preferred embodiment of the present invention, a motion regulating mechanism is provided between the linear motion mechanism 32 and the connecting rod 7 to ensure the linear motion of the linear motion mechanism 32 .

According to a preferred embodiment of the present invention, the first electronically controlled linear motion module 4 includes a rotary motor 1 and a transmission mechanism that converts rotary motion into linear motion. The transmission mechanism includes a ball screw mechanism, and the nut of the ball screw is fixedly connected to the On the rotor of the rotary motor 1, the nut is driven to rotate by the motor rotation, and the nut transmits force to the screw through the ball, thereby driving the screw to move in a straight line.

According to a preferred embodiment of the present invention, the above-mentioned transmission mechanism may also be a worm gear, a rack and pinion mechanism or a lead screw-nut mechanism.

According to a preferred embodiment of the present invention, the second electronically controlled linear motion module 10 includes a transmission mechanism for the rotary motor 9 to convert rotary motion into linear motion, and the transmission mechanism adopts a screw-nut mechanism with self-locking function. The nut is fixedly connected on the rotor of the rotary motor 9, and the rotation of the motor drives the nut to rotate, and the nut drives the leading screw to do linear motion.

Preferably, the present invention provides a fault diagnosis system, which can transmit fault information to the electronic control unit 31 when a certain braking component fails.

Preferably, the present invention also provides a fault alarm system. When the fault diagnosis system diagnoses a fault in the pedal displacement active control motor hydraulic brake system, the alarm device is activated to provide an alarm to the driver at the first time.

According to national regulations, the braking system must take into account the occurrence of failure and the failure of some braking components, and it must also be able to transmit the force of the driver's pedaling to the braking system for a certain intensity of braking. The electro-hydraulic brake system with pedal displacement active control of the present invention is also designed with a failure protection scheme.

Motor 1 cannot provide torque at the start of braking or during braking, or the linear motion mechanism 32 is damaged so that motion cannot be transmitted. The fault diagnosis system diagnoses the fault information and transmits it to the electronic control unit 31. The second electronically controlled linear motion module of the electronic control unit 31 Motor 9 torque adjustment in 10 (the required master cylinder piston displacement Sh is determined by the pedal displacement, the displacement of the second electronically controlled linear motion module S ₂ =S _h L ₁ /L,), drives the linear motion mechanism 33, and the second motor The force generated by the linear motion control module and the pedal force provided by the driver together drive the first piston 22 to perform desired linear motion through the connecting rod 7 .

The motor 9 cannot provide torque at the start of braking or during braking, or the linear motion mechanism 33 is damaged so that the motion cannot be transmitted. The fault diagnosis system diagnoses the fault information and transmits it to the electronic control unit 31. The electronic control unit 31 controls the first electronically controlled linear motion. Motor 1 in module 4 performs torque adjustment (the required master cylinder piston Sh is determined by the pedal displacement, and the first electronically controlled linear motion module adjusts the displacement S=S _h L ₂ /LS _p ), at this time the second electronically controlled linear motion module The linear motion mechanism is in a locked state, and the motor 1 drives the linear motion mechanism 32 to move, and then the connecting rod 7 drives the piston to perform desired linear motion.

When the first and second electronically controlled linear motion modules fail simultaneously at the start of braking or during braking, the second electronically controlled linear motion module is in a locked state. At this time, the driver slams on the brake pedal and directly pushes the main cylinder, although there is no booster at this time, it cannot provide enough braking force, and a certain degree of braking force is still of great help to the safety of the driver during emergency braking.

There are some problems in the braking system of traditional cars equipped with vacuum boosters. The vacuum booster cannot provide boost when it exceeds the boost range, resulting in an unassisted pedal stroke during emergency braking. Due to the limitation of the layout space in the car, the vacuum The limited size of the booster makes it difficult to achieve better braking performance. When the electronic hydraulic braking system with pedal displacement active control of the present invention is applied to a traditional automobile, it can fully utilize the advantages of the dual motors in a wide range of speed regulation, high control precision, good dynamics, and fast response time, and make up for this defect.

The electronic hydraulic brake system with pedal displacement active control of the present invention can also be applied to new energy vehicles, with the goal of maximizing the braking energy recovery of the drive motor, and the output torque of the dual motors is adjusted through the electronic control unit, so that the regenerative Dynamic and hydraulic brakes together form the total braking force.

The above description of the embodiments is for those of ordinary skill in the art to understand and apply the present invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments, and apply the general principles described here to other embodiments without creative efforts. Therefore, the present invention is not limited to the embodiments herein. Improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should fall within the protection scope of the present invention.

Claims (9)

1. a kind of EHB of pedal displacement active control it is characterised in that：Including：

Brake pedal；

For obtaining the pedal displacement sensor of driver's brake pedal displacement；

For obtaining the displacement transducer of the second automatically controlled Linear Moving Module displacement；

Master cylinder, it is coupled with each wheel cylinder hydraulic pressure through ABS/ESP module；

First automatically controlled Linear Moving Module, it passes through motion adjustment mechanism and rod hinge connection, thus being connected, this mould with master cylinder The motor of block can active control pedal displacement to the good brake feel of driver；

Second automatically controlled Linear Moving Module, it is connected with master cylinder by connecting rod, and the letter according to pedal displacement sensor Number adjust master cylinder hydraulic braking force size；

ABS/ESP module, for adjusting the hydraulic braking force of each wheel cylinder；

ECU ECU, receives the signal that each sensor records, and calculates the size of required hydraulic braking force in this time braking And first, second respective displacement of automatically controlled Linear Moving Module.

2. pedal displacement active control according to claim 1 EHB it is characterised in that：

Described first, second automatically controlled Linear Moving Module includes ECU ECU, motor and straight-line motion mechanism, described motor Receive the Torque-adjusting signal control straight-line motion mechanism that ECU ECU sends.

3. pedal displacement active control according to claim 2 EHB it is characterised in that：

, by integrated installation on brake pedal, hydraulic coupling transducer arrangements are in the brake piping of master cylinder for described pedal displacement sensor On, displacement transducer is installed on the straight-line motion mechanism of the second automatically controlled Linear Moving Module, sensor, motor and ECU ECU is connected by control circuit and transmits signal.

4. pedal displacement active control according to claim 3 EHB it is characterised in that：

Described first automatically controlled Linear Moving Module includes electric rotating machine and converts rotational motion to the drive mechanism moving along a straight line, Drive mechanism includes worm-and-wheel gear, pinion and rack, guilde screw or ball-screw；This module being capable of active control The pedal displacement of driver, to operator brake sensation.

5. pedal displacement active control according to claim 4 EHB it is characterised in that：

Described second automatically controlled Linear Moving Module includes electric rotating machine and converts rotational motion to the drive mechanism moving along a straight line, Drive mechanism is using the guilde screw mechanism with auto-lock function.

6. pedal displacement active control according to claim 5 EHB it is characterised in that：

Described first automatically controlled Linear Moving Module, it passes through motion adjustment mechanism and rod hinge connection, the second automatically controlled linear motion mould Block and rod hinge connection, connecting rod is connected with the first piston of master cylinder, by the first automatically controlled Linear Moving Module and the second electricity The collaborative work of control Linear Moving Module carries out dynamic regulation to the hydraulic braking force of master cylinder, drives master cylinder piston to produce desired Linear motion.

7. pedal displacement active control according to claim 6 EHB it is characterised in that：

First working chamber of master cylinder and the second working chamber are connected with ABS/ESP module by fluid pressure line respectively；Connecting rod and first Piston is connected, and promotes first piston, and the first working chamber promotes second piston to produce desired linear motion, brake fluid warp after building pressure Cross fluid pressure line and flow to ABS/ESP module, then can adjust the brake force that each wheel cylinder produces.

8. pedal displacement active control according to claim 7 EHB it is characterised in that：

The EHB of described pedal displacement active control provides fault diagnosis system, when certain brake component lost efficacy When breaking down, fault message can be passed to ECU；

The EHB of described pedal displacement active control provides failure warning system, when fault diagnosis system diagnosis When going out system malfunctions, alarm activation, the very first time provides to driver and reports to the police.

9. pedal displacement active control according to claim 8 EHB it is characterised in that：

When the first or second automatically controlled Linear Moving Module lost efficacy, ECU can be by the control algolithm pair under failure mode The motor of another automatically controlled Linear Moving Module carries out torque adjusting it is ensured that certain hydraulic braking force；When first, second is automatically controlled straight When line motion module lost efficacy simultaneously, system enters manual machine on-position, and hydraulic coupling is all provided by the pedal force of driver.