CN114670673B - Braking torque control system and method - Google Patents

Abstract

The invention provides a braking torque control system and a braking torque control method, comprising a braking torque input deflector rod, wherein the braking torque input deflector rod is connected with a vehicle controller VCU to send a braking demand torque command to the vehicle controller VCU, and the vehicle controller VCU sends a corresponding braking demand torque command to a motor controller MCU through a CAN bus to control a motor to generate a corresponding braking demand torque; in the downhill process of the vehicle, the braking torque input deflector rod is arranged to keep the braking feedback power stable, so that better feedback efficiency is obtained; through the synergistic effect of the brake torque input deflector rod, the accelerator pedal and the brake pedal, the operation of a driver on acceleration and braking can be reduced in the long downhill process; when the vehicle runs down a slope or turns, the deceleration and acceleration in the process of running down the slope can be realized through simple control of the brake pedal and the accelerator pedal.

Description

Braking torque control system and method

Technical field

The present invention relates to the technical field of vehicle control methods, and in particular to a braking torque control system and method.

Background technique

The working roads in the mining area are mainly uphill and downhill. For pure electric mine trucks, energy feedback when going downhill is the main energy-saving means. Therefore, the braking force and speed control of the mine cars during the downhill process are very important. The traditional control method is for the driver to judge the current speed of the mine car. When the speed is too high, he decelerates the mine car by pressing the brake pedal. When he judges that the speed is too low, he depresses the accelerator pedal to accelerate the mine car.

However, there are still some shortcomings in the above control process:

1) The working roads in the mining area are complex, with many slope changes and curves, and there are speed limits during the downhill process. The driver must constantly step on the brake pedal and accelerator pedal to control the vehicle speed. The work intensity is high and fatigue is easy.

2) Most of the working roads in the mining area are unpaved, and the vehicle is severely bumpy during driving. During the downhill process, the driver cannot stabilize the brake pedal opening, resulting in unstable energy feedback power and low feedback efficiency.

Therefore, there is an urgent need to provide a stable and effective braking torque control system and method to solve the above-mentioned defects and deficiencies in the prior art.

Contents of the invention

In order to solve the above-mentioned defects and deficiencies in the prior art, the present invention provides a braking torque control system and method.

The technical solution provided by the present invention is as follows: a braking torque control system, characterized in that: the system includes a braking torque input lever, and the braking torque input lever is connected to the vehicle controller VCU to provide control to the vehicle. The controller VCU sends a braking demand torque command, and the vehicle controller VCU sends a corresponding braking demand torque command to the motor controller MCU through the CAN bus to control the motor to generate the corresponding braking demand torque.

Further, the system also includes an accelerator pedal and a brake pedal, which can adjust the braking demand torque generated by the motor.

Furthermore, when the driver depresses the brake pedal, the braking demand torque gradually increases according to the depth of the pedal depression;

When the driver depresses the accelerator pedal, the braking demand torque gradually decreases according to the depth of depressing the pedal.

When the driver releases the brake pedal and accelerator pedal, the braking demand torque returns to the initial value.

Further, the braking torque input lever includes a total of N gears from 0 to N. The higher the gear, the greater the corresponding braking demand torque generated by the motor.

Further, the maximum adjustment value of the accelerator pedal and the brake pedal to the braking demand torque generated by the motor is lower than the difference in the corresponding braking demand torque generated by the motor between two adjacent gears.

Further, when the driver's brake pedal depression depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a higher gear to increase the braking demand torque;

When the driver's accelerator pedal depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a lower gear to reduce the braking demand torque.

Further, the braking demand torque Tb_veh is calculated as follows:

Tb_veh＝Tx+Tb+Tp

in,

Tx is the set braking torque in the corresponding gear of the braking torque input lever, x is the corresponding gear of the braking torque input lever, x=0,1,2,3,...N; T0=0; And satisfy T0<T1<T2<T3<T4<......TN;

Tb is the braking torque corresponding to the brake pedal, calculated as follows:

Tb=Mx(T)*α, where Mx(T) is the braking torque of the brake pedal corresponding to 1% of the opening in each gear; α is the brake pedal opening;

Tp is the driving torque corresponding to the accelerator pedal, calculated as follows:

Tp=-Nx(T)*β, where Nx(T) is the accelerator pedal driving torque corresponding to 1% opening in each gear; β is the accelerator pedal opening.

A braking torque control method is also proposed, including the following steps:

1) When the vehicle continues to go downhill, the driver selects the appropriate gear position of the braking torque input lever according to the slope. The vehicle enters the downhill constant torque braking mode, and the braking torque input lever turns to the vehicle controller VCU. Send the braking demand torque command, and the vehicle controller VCU sends the corresponding braking demand torque command to the motor controller MCU through the CAN bus to control the motor to generate the corresponding braking demand torque;

2) When going downhill on a sharp turning section, the driver adjusts the braking demand torque through the accelerator pedal or brake pedal:

When the driver depresses the brake pedal, the braking demand torque gradually increases according to the depth of pedal depression;

When the driver depresses the accelerator pedal, the braking demand torque gradually decreases according to the depth of depressing the pedal.

When the driver releases the brake pedal and accelerator pedal, the braking demand torque returns to the initial value.

3) When the driver's brake pedal depression depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a higher gear to increase the braking demand torque;

When the driver's accelerator pedal depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a lower gear to reduce the braking demand torque.

The beneficial effects achieved by the present invention compared with the prior art are:

(1) The present invention provides a braking torque control system and method. During the downhill process of the vehicle, by setting the braking torque input lever, the power of the braking feedback is kept stable and better feedback efficiency is obtained.

(2) The present invention provides a braking torque control system and method. Through the synergistic effect of the braking torque input lever, the accelerator pedal and the brake pedal, the driver's response to acceleration and braking can be reduced during long downhill processes. operation.

(3) The present invention provides a braking torque control system and method. When encountering a slope change or turning when going downhill, deceleration and acceleration during the downhill process can be achieved through simple control of the brake pedal and accelerator pedal. .

Description of drawings

Figure 1 is a schematic diagram of the logical structure of the present invention.

Figure 2 is a schematic diagram of the braking torque input lever gear position of the present invention.

Figure 3 is a diagram showing the influence of the accelerator pedal and the brake pedal on the braking demand torque in the 2nd gear position of the braking torque input lever of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front end", "rear end", "both ends", "one end", and "the other end" The indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. They are not intended to indicate or imply that the device or element referred to must have a specific orientation or in a specific manner. orientation construction and operation and therefore should not be construed as limitations of the invention. In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise clearly stated and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection. , it can be a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, or it can be an internal connection between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood on a case-by-case basis.

[Example 1]

Figure 1 shows a braking torque control system provided in Embodiment 1 of the invention. The system includes a braking torque input lever. The braking torque input lever is connected to the vehicle controller VCU to provide control to the vehicle. The controller VCU sends a braking demand torque command, and the vehicle controller VCU sends a corresponding braking demand torque command to the motor controller MCU through the CAN bus to control the motor to generate the corresponding braking demand torque.

As shown in Figure 2, the braking torque input lever includes a total of N gears from 0 to N. The higher the gear, the greater the corresponding braking demand torque generated by the motor. The driver can select the appropriate braking torque input lever gear according to the slope, so that the vehicle enters the downhill constant torque braking mode in this gear. This torque will not be affected by vehicle bumps, brake pedal instability, etc. influence of factors. In this implementation, there are five gears: 0, 1, 2, 3, and 4. Those skilled in the art know that the gears can also be set to more or less gears according to actual needs. As shown in Figure 2, when the braking torque input lever is in the 0 position, it is a non-downhill constant torque braking mode.

There is a certain range of torque between each gear. During the downhill process, there are many sharp turns. It is necessary to slow down before entering the bend and accelerate after exiting the bend. Although the driver can adjust the brake through the brake torque input lever. However, the torque range of the brake lever is large, which may easily cause the driver to be unable to find the appropriate braking demand torque, and the braking torque change between adjacent gears is not gentle.

Therefore, as shown in Figure 3, the system also includes an accelerator pedal and a brake pedal. The accelerator pedal and brake pedal can adjust the braking demand torque generated by the motor, which is specifically expressed as:

When the driver depresses the brake pedal, the braking demand torque gradually increases according to the depth of pedal depression;

When the driver depresses the accelerator pedal, the braking demand torque gradually decreases according to the depth of depressing the pedal.

When the driver releases the brake pedal and accelerator pedal, the braking demand torque returns to the initial value.

As shown in Figure 3, the maximum adjustment value of the braking demand torque generated by the motor by the accelerator pedal and the brake pedal is lower than the difference in the corresponding braking demand torque generated by the motor between two adjacent gears. So on this basis:

When the driver's brake pedal depression depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the brake torque input lever to a higher gear to increase the braking demand torque;

When the driver's accelerator pedal depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a lower gear to reduce the braking demand torque.

Preferably, in this embodiment, the braking demand torque Tb_veh is calculated as follows:

Tb_veh＝Tx+Tb+Tp

in,

Tx is the set braking torque in the corresponding gear of the braking torque input lever, x is the corresponding gear of the braking torque input lever, x=0,1,2,3,...N; T0=0; And satisfy T0<T1<T2<T3<T4<......TN;

Tb is the braking torque corresponding to the brake pedal, calculated as follows:

Tb=Mx(T)*α, where Mx(T) is the braking torque of the brake pedal corresponding to every 1% opening in each gear; α is the brake pedal opening, and Mx(T) can be calibrated through experiments get;

Tp is the driving torque corresponding to the accelerator pedal, calculated as follows:

Tp=-Nx(T)*β, where Nx(T) is the accelerator pedal driving torque corresponding to every 1% opening in each gear; β is the accelerator pedal opening, and Nx(T) can be obtained through experimental calibration .

[Example 2]

Embodiment 2 of the present invention also provides a braking torque control method, which includes the following steps:

1) When the vehicle continues to go downhill, the driver selects the appropriate gear position of the braking torque input lever according to the slope. The vehicle enters the downhill constant torque braking mode, and the braking torque input lever turns to the vehicle controller VCU. Send the braking demand torque command, and the vehicle controller VCU sends the corresponding braking demand torque command to the motor controller MCU through the CAN bus to control the motor to generate the corresponding braking demand torque;

2) When going downhill on a sharp turning section, the driver adjusts the braking demand torque through the accelerator pedal or brake pedal:

When the driver depresses the brake pedal, the braking demand torque gradually increases according to the depth of pedal depression;

When the driver depresses the accelerator pedal, the braking demand torque gradually decreases according to the depth of depressing the pedal.

When the driver releases the brake pedal and accelerator pedal, the braking demand torque returns to the initial value.

3) When the driver's brake pedal depression depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a higher gear to increase the braking demand torque;

When the driver's accelerator pedal depth reaches the maximum value and the braking torque still cannot meet the requirements, the driver is prompted to adjust the braking torque input lever to a lower gear to reduce the braking demand torque.

When the vehicle is going downhill, by setting the brake torque input lever, the power of the brake feedback is kept stable and better feedback efficiency is obtained; through the synergy of the brake torque input lever, the accelerator pedal and the brake pedal, During the long downhill process, it can reduce the driver's acceleration and braking operations; during the downhill process, when encountering slope changes or turns, deceleration during the downhill process can be achieved through simple control of the brake pedal and accelerator pedal. and acceleration.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as further limiting the scope of the claimed application.

Claims (3)

1. A brake torque control system, characterized by: the system comprises a braking torque input deflector rod, wherein the braking torque input deflector rod is connected with a vehicle control unit VCU to send a braking demand torque instruction to the vehicle control unit VCU, and the vehicle control unit VCU sends a corresponding braking demand torque instruction to a motor controller MCU through a CAN bus to control a motor to generate a corresponding braking demand torque;

the system further includes an accelerator pedal and a brake pedal capable of adjusting a braking demand torque generated by the motor;

when a driver presses a brake pedal, the brake demand torque is gradually increased according to the pedal pressing depth;

when the driver depresses the accelerator pedal, the brake demand torque gradually decreases according to the pedal depression depth,

when the driver releases the brake pedal and the accelerator pedal, the brake demand torque returns to the initial value;

the braking torque input deflector rod comprises 0 to N gears, wherein the higher the gears are, the larger the corresponding braking demand torque generated by the motor is;

the maximum adjustment value of the braking demand torque generated by the motor by the accelerator pedal and the brake pedal is lower than the difference value of the corresponding braking demand torque generated by the motor between two adjacent gears;

when the stepping depth of the brake pedal of the driver reaches the maximum value and the brake torque still cannot meet the requirement, prompting the driver to adjust the brake torque input deflector rod to a higher first gear so as to increase the brake required torque;

when the depth of depression of the accelerator pedal reaches the maximum value and the braking torque still cannot meet the requirement, the driver is prompted to adjust the braking torque input deflector rod to a lower first gear so as to reduce the braking required torque.

2. A brake torque control system as claimed in claim 1, wherein: the brake demand torque tb_veh is calculated as follows:

Tb_veh＝Tx+Tb+Tp

wherein,

tx is a set detent torque at a corresponding gear of the detent torque input lever, x is a corresponding gear of the detent torque input lever, x=0, 1,2,3, … … N; t0=0; and satisfies T0< T1< T2< T3< T4< … … TN;

tb is the corresponding braking torque of the brake pedal, and is calculated as follows:

tb=mx (T) ×α, where Mx (T) is a brake pedal braking torque corresponding to each 1% opening degree in each gear; alpha is the opening degree of a brake pedal;

tp is the driving torque corresponding to the accelerator pedal, calculated as follows:

tp= -Nx (T) ×β, where Nx (T) is an accelerator pedal driving torque corresponding to each 1% opening in each gear; beta is the opening of the oil accelerator pedal.

3. A control method of a brake torque control system according to any one of claims 1 to 2, characterized in that: the method comprises the following steps:

1) When the vehicle continuously descends, a driver selects a proper corresponding gear of a braking torque input deflector rod according to the gradient, the vehicle enters a descending constant torque braking mode, the braking torque input deflector rod sends a braking demand torque command to a whole vehicle controller VCU, and the whole vehicle controller VCU sends the corresponding braking demand torque command to a motor controller MCU through a CAN bus so as to control a motor to generate corresponding braking demand torque;

2) During a sharp turn during downhill descent, the driver adjusts the braking demand torque via an accelerator pedal or a brake pedal:

when a driver presses a brake pedal, the brake demand torque is gradually increased according to the pedal pressing depth;

when the driver depresses the accelerator pedal, the brake demand torque gradually decreases according to the pedal depression depth,

when the driver releases the brake pedal and the accelerator pedal, the brake demand torque returns to the initial value;

3) When the stepping depth of the brake pedal of the driver reaches the maximum value and the brake torque still cannot meet the requirement, prompting the driver to adjust the brake torque input deflector rod to a higher first gear so as to increase the brake required torque;

when the depth of depression of the accelerator pedal reaches the maximum value and the braking torque still cannot meet the requirement, the driver is prompted to adjust the braking torque input deflector rod to a lower first gear so as to reduce the braking required torque.