阅读说明：本技术 制动系统abs路感补偿与行程模拟耦合控制装置及方法 (ABS road feel compensation and stroke simulation coupling control device and method for brake system ) 是由 王高升 肖培杰 张鸣 于 2021-10-08 设计创作，主要内容包括：本发明公开了一种制动系统ABS路感补偿与行程模拟耦合控制装置及方法,装置包括车轮、EMB系统、CAN总线、ABS路感和行程模拟耦合控制器、第一高速开关阀、第二高速开关阀、油泵、油箱、制动踏板、输入推杆、力传感器及制动主缸；所述车轮与EMB系统相连,EMB系统与CAN总线电连接,CAN总线与ABS路感和行程模拟耦合控制器电连接；所述ABS路感和行程模拟耦合控制器分别与第一高速开关阀、第二高速开关阀及电机电连接。本发明结构简单,成本低,利用ABS路感和行程模拟耦合控制器对第一高速开关阀、第二高速开关阀和电机进行干预,可以在实现踏板行程模拟的前提下,同时兼顾ABS路感,明显提升线控制动系统的制动品质。(The invention discloses a device and a method for controlling ABS road feel compensation and stroke simulation coupling of a braking system, wherein the device comprises wheels, an EMB system, a CAN bus, an ABS road feel and stroke simulation coupling controller, a first high-speed switch valve, a second high-speed switch valve, an oil pump, an oil tank, a brake pedal, an input push rod, a force sensor and a brake master cylinder; the wheels are connected with an EMB system, the EMB system is electrically connected with a CAN bus, and the CAN bus is electrically connected with an ABS road sensing and stroke simulation coupling controller; the ABS road sensing and stroke analog coupling controller is respectively and electrically connected with the first high-speed switch valve, the second high-speed switch valve and the motor. The invention has simple structure and low cost, and can intervene the first high-speed switch valve, the second high-speed switch valve and the motor by utilizing the ABS road feel and stroke simulation coupling controller, thereby taking the ABS road feel into consideration on the premise of realizing pedal stroke simulation and obviously improving the braking quality of the brake-by-wire system.)

1. The utility model provides a braking system ABS road feel compensation and stroke simulation coupling control device which characterized in that: the device comprises wheels, an EMB system, a CAN bus, an ABS road feel and stroke simulation coupling controller, a first high-speed switch valve, a second high-speed switch valve, an oil pump, an oil tank, a brake pedal, an input push rod, a force sensor and a brake master cylinder; the wheels are connected with an EMB system, the EMB system is electrically connected with a CAN bus, and the CAN bus is electrically connected with an ABS road sensing and stroke simulation coupling controller; the ABS road sensing and stroke analog coupling controller is respectively electrically connected with the first high-speed switch valve, the second high-speed switch valve and the motor; the brake pedal is connected with one end of an input push rod, and the other end of the input push rod extends into the brake master cylinder and is connected with the force sensor; a first piston and a second piston are arranged in the brake master cylinder, the second piston is connected with the rodless cavity end of the brake master cylinder through a second spring, and the first piston is connected with the second piston through a first spring; the first piston is connected with the force sensor; the second piston divides a rodless cavity of the brake master cylinder into a first oil cavity and a second oil cavity, and the first oil cavity is positioned between the first piston and the second piston;

the oil pump is connected with the motor, the inlet of the oil pump is connected with the oil tank through an oil inlet pipe, the outlet of the oil pump is connected with the inlet of the one-way valve through a pipeline, the outlet of the one-way valve is connected with the first oil liquid cavity and the second oil liquid cavity through two branch pipes respectively, a first high-speed switch valve is arranged on the branch pipe connected with the second oil liquid cavity, the outlet of the one-way valve is connected with the oil inlet pipe through another branch pipe, and a second high-speed switch valve is arranged on the other branch pipe.

2. The ABS road feel compensation and stroke analog coupling control device of claim 1, wherein: the brake master cylinder is internally provided with a second limiting rod and a first limiting rod, and the first limiting rod is positioned in a rod cavity of the brake master cylinder and used for limiting the first piston; the second limiting rod is located in the first oil liquid cavity and limits the second piston.

3. A brake system ABS road feel compensation and travel simulation coupled control method using the brake system ABS road feel compensation and travel simulation coupled control apparatus of claim 1 or 2, comprising the steps of:

1) before braking, the oil pump runs to control the first high-speed switch valveThe electricity and the second high-speed switch valve are powered off; so that the second oil piston cavity and the third oil piston cavity maintain the initial pressure P₁After pressure maintaining, controlling the first high-speed switch valve to be powered off, the second high-speed switch valve to be powered off, and stopping the motor from running;

2) the method comprises the steps that a brake pedal is stepped on, an ABS road feel and stroke simulation coupling controller inquires a target pedal stroke at the moment according to a force sensor value, a target pedal force and a pedal stroke Map, then the volume discharge amount of a first oil liquid cavity is calculated, and a second high-speed switch valve is controlled to be powered on, a motor does not operate and a first high-speed switch valve is controlled to be powered off until the volume discharge amount of the first oil liquid cavity is reached, and the second high-speed switch valve is controlled to be powered off, the motor does not operate and the first high-speed switch valve is controlled to be powered off;

3) the ABS road feel and stroke analog coupling controller receives a wheel slip rate signal from the CAN bus in real time, if the wheel slip rate signal is greater than the highest slip rate value, the ABS road feel adjusting time is calculated, and the first high-speed switch valve and the second high-speed switch valve are alternately powered on or powered off and the motor is controlled to run according to the ABS road feel adjusting time value so as to reduce or increase the volume of the second oil liquid cavity; if the wheel slip rate signal is less than the highest slip rate value, returning to the step 2);

4) and when the brake pedal is released, the ABS road feel and stroke simulation coupling controller inquires corresponding target pedal stroke according to the force sensor value and the target pedal force and pedal stroke Map, calculates the volume increment of the first oil liquid cavity, and then controls the motor to run and the first high-speed switch valve and the second high-speed switch valve to be powered off until the volume increment of the first oil liquid cavity is reached, and controls the motor to stop running and the first high-speed switch valve and the second high-speed switch valve to be powered off.

4. The ABS road feel compensation and stroke analog coupling control method of claim 3, wherein in step 2), when the volume of the second oil chamber is decreased or increased, the second oil chamber is determined according to the odd or even number of the adjustment times, and when the adjustment times are odd, the first high-speed switch valve and the second high-speed switch valve are energized to control the motor not to operate; when the adjusting times is even, the first high-speed switch valve is controlled to be powered on, the second high-speed switch valve is controlled to be powered off, and the motor runs.

5. The ABS road feel compensation and stroke analog coupling control method for a brake system according to claim 3, wherein in step 2) and step 4), the volume discharge amount Δ Q of the first oil chamber₁And delta Δ Q₂The calculation formula of (a) is as follows:

in the formula: d represents the diameter of the second oil piston chamber; x is the number of_i、x_i-1Representing the target pedal stroke at the present time and the previous time, respectively.

6. The ABS road feel compensation and stroke analog coupling control method according to claim 3, wherein in step 2), the ABS road feel adjustment time t is calculated by the following formula:

t＝t₁-t₂

in the formula: t is t₁The time when the lowest slip value appears at the current moment in the wheel slip rate signal is taken as the time; t is t₂The time at which the highest slip value occurs at the next instant in the wheel slip rate signal.

Technical Field

The invention relates to a device and a method for controlling ABS road feel compensation and stroke analog coupling of a braking system.

Background

The modern new development of automobiles, namely electromotion, intellectualization, networking and sharing, puts forward a lot of new requirements on automobile braking systems, the traditional braking systems are difficult to meet, and the novel wire control braking systems come up at the right moment. The brake-by-wire system is an advanced electrically-controlled novel automobile brake system. The device consists of a built-in pedal displacement sensor, a pedal feeling simulator, a motor, a speed reduction transmission mechanism, a brake master cylinder, a shell, a controller and the like. The traditional vacuum booster braking system is a purely mechanical braking system which realizes boosting by depending on vacuum, and the line control electronic hydraulic braking system takes a motor as a power source, gets rid of vacuum dependence, and introduces an electric control unit and various sensors, so that the braking system realizes electric control. Compared with the traditional vacuum power-assisted brake system, the brake-by-wire electronic hydraulic brake system has many advantages.

At present, a brake-by-wire system can be divided into an electronic hydraulic brake system (EHB) and an electronic mechanical brake system (EMB), and most EHB systems and all EMB systems need to be provided with pedal travel simulation devices for brake pedals to obtain corresponding brake pedal feeling, so that different driving styles are met. Often, when satisfying this type of demand, the producer can neglect the ABS road feel that carries back the driver when emergency braking of the whole car of traditional vacuum booster unit. Most of the existing novel brake-by-wire systems are not provided with and integrated with corresponding ABS brake pedal feeling feedback.

Disclosure of Invention

In order to solve the technical problems, the invention provides a brake system ABS road feel compensation and stroke simulation coupling control device and method which are simple in structure, low in cost and capable of achieving both ABS road feel and pedal stroke simulation.

The technical scheme adopted by the invention is as follows: the utility model provides a braking system ABS road feel compensation and stroke simulation coupling control device which characterized in that: the device comprises wheels, an EMB system, a CAN bus, an ABS road feel and stroke simulation coupling controller, a first high-speed switch valve, a second high-speed switch valve, an oil pump, an oil tank, a brake pedal, an input push rod, a force sensor and a brake master cylinder; the wheels are connected with an EMB system, the EMB system is electrically connected with a CAN bus, and the CAN bus is electrically connected with an ABS road sensing and stroke simulation coupling controller; the ABS road sensing and stroke analog coupling controller is respectively electrically connected with the first high-speed switch valve, the second high-speed switch valve and the motor; the brake pedal is connected with one end of an input push rod, and the other end of the input push rod extends into the brake master cylinder and is connected with the force sensor; a first piston and a second piston are arranged in the brake master cylinder, the second piston is connected with the rodless cavity end of the brake master cylinder through a second spring, and the first piston is connected with the second piston through a first spring; the first piston is connected with the force sensor; the second piston divides a rodless cavity of the brake master cylinder into a first oil cavity and a second oil cavity, and the first oil cavity is positioned between the first piston and the second piston;

the oil pump is connected with the motor, the inlet of the oil pump is connected with the oil tank through an oil inlet pipe, the outlet of the oil pump is connected with the inlet of the one-way valve through a pipeline, the outlet of the one-way valve is connected with the first oil liquid cavity and the second oil liquid cavity through two branch pipes respectively, a first high-speed switch valve is arranged on the branch pipe connected with the second oil liquid cavity, the outlet of the one-way valve is connected with the oil inlet pipe through another branch pipe, and a second high-speed switch valve is arranged on the other branch pipe.

In the ABS road feel compensation and stroke analog coupling control device for the braking system, a second limit rod and a first limit rod are arranged in the brake master cylinder, and the first limit rod is located in the rod cavity of the brake master cylinder to limit the first piston; the second limiting rod is located in the first oil liquid cavity and limits the second piston.

A method for controlling the ABS road feel compensation and the travel simulation coupling of a braking system by using the ABS road feel compensation and travel simulation coupling control device of the braking system comprises the following steps:

1) before braking, the oil pump runs to control the first high-speed switch valve to be powered on and the second high-speed switch valve to be powered off; so that the second oil piston cavity and the third oil piston cavity maintain the initial pressure P₁After pressure maintaining, controlling the first high-speed switch valve to be powered off, the second high-speed switch valve to be powered off, and stopping the motor from running;

2) the method comprises the steps that a brake pedal is stepped on, an ABS road feel and stroke simulation coupling controller inquires a target pedal stroke at the moment according to a force sensor value, a target pedal force and a pedal stroke Map, then the volume discharge amount of a first oil liquid cavity is calculated, and a second high-speed switch valve is controlled to be powered on, a motor does not operate and a first high-speed switch valve is controlled to be powered off until the volume discharge amount of the first oil liquid cavity is reached, and the second high-speed switch valve is controlled to be powered off, the motor does not operate and the first high-speed switch valve is controlled to be powered off;

3) the ABS road feel and stroke analog coupling controller receives a wheel slip rate signal from the CAN bus in real time, if the wheel slip rate signal is greater than the highest slip rate value, the ABS road feel adjusting time is calculated, and the first high-speed switch valve and the second high-speed switch valve are alternately powered on or powered off and the motor is controlled to run according to the ABS road feel adjusting time value so as to reduce or increase the volume of the second oil liquid cavity; if the wheel slip rate signal is less than the highest slip rate value, returning to the step 2);

4) and when the brake pedal is released, the ABS road feel and stroke simulation coupling controller inquires corresponding target pedal stroke according to the force sensor value and the target pedal force and pedal stroke Map, calculates the volume increment of the first oil liquid cavity, and then controls the motor to run and the first high-speed switch valve and the second high-speed switch valve to be powered off until the volume increment of the first oil liquid cavity is reached, and controls the motor to stop running and the first high-speed switch valve and the second high-speed switch valve to be powered off.

In the ABS road feel compensation and stroke analog coupling control method for the brake system, in the step 2), when the volume of the second oil cavity is reduced or increased, the judgment is carried out according to the odd and even of the adjusting times, and when the adjusting times are odd, the first high-speed switch valve and the second high-speed switch valve are electrified to control the motor not to run; when the adjusting times is even, the first high-speed switch valve is controlled to be powered on, the second high-speed switch valve is controlled to be powered off, and the motor runs.

In the above ABS road feel compensation and stroke analog coupling control method for the braking system, in the step 2) and the step 4), the volume discharge amount Δ Q of the first oil chamber is₁And delta Δ Q₂The calculation formula of (a) is as follows:

wherein d represents the diameter of the second oil piston chamber; x is the number of_i、x_i-1Representing the target pedal travel at the current time and the previous time, respectively

In the above ABS road feel compensation and stroke analog coupling control method for the braking system, in step 2), the calculation formula of the ABS road feel adjusting time t is:

t＝t₁-t₂

in the formula, t₁The time when the lowest slip value appears at the current moment in the wheel slip rate signal is taken as the time; t is t₂The time at which the highest slip value occurs at the next instant in the wheel slip rate signal.

Compared with the prior art, the invention has the beneficial effects that: the ABS road feel compensation and stroke simulation coupling control device of the braking system has the advantages of simple structure and low cost. According to the invention, the ABS road feel and stroke simulation coupling controller is used for acquiring the wheel slip value signal from the CAN bus, calculating the ABS road feel adjusting time, and controlling the on-off of the first high-speed switch valve, the on-off of the second high-speed switch valve and whether the motor runs or not on line, so that the brake pedal feel fed back to a driver when the ABS function is triggered is provided, the driver CAN sense the brake pedal feel, and the brake safety is improved. The invention realizes the pedal travel simulation and gives consideration to the ABS road feeling, can obviously improve the brake quality of the brake-by-wire system, ensures that a driver can sense the brake state of the brake system all the time, and further ensures the driving safety.

Drawings

Fig. 1 is a schematic structural diagram of an ABS road feel compensation and stroke analog coupling control device of a braking system according to the present invention.

FIG. 2 is a flow chart of the ABS road feel compensation and travel simulation coupling control method of the braking system of the present invention.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

As shown in fig. 1, the ABS road feel compensation and stroke simulation coupling control device of the braking system of the present invention includes a wheel 1, an EMB system 2, a CAN bus 3, an ABS road feel and stroke simulation coupling controller 4, a first high-speed switch valve 5, a check valve 6, a second high-speed switch valve 7, an oil pump 8, a motor 9, an oil tank 10, a brake pedal 11, an input push rod 12, a force sensor 14, a brake master cylinder, a rod chamber 13, a first oil chamber 16, a first spring 15, a second oil chamber 18, a first limit rod 20, a second limit rod 19, and a second spring 17. The vehicle wheel 1 is connected with the EMB system 2, the EMB system 2 is connected with the CAN bus 3 through a signal line, the CAN bus 3 is connected with the ABS road sensing and stroke simulation coupling controller 4 through a signal line, and time signal interaction among the EMB system 2, the CAN bus 3, the ABS road sensing and stroke simulation coupling controller 4 is achieved.

The ABS road sensing and stroke analog coupling controller 4 is respectively connected with the first high-speed switch valve 5, the second high-speed switch valve 7 and the motor 9 to control the same. The brake pedal 11 is connected with one end of an input push rod 12, and the other end of the input push rod 12 extends into the brake master cylinder to be connected with a force sensor 14. A first piston and a second piston are arranged in the brake master cylinder, the second piston is connected with the rodless cavity end of the brake master cylinder through a second spring 17, and the first piston is connected with the second piston through a first spring 15; the first piston is connected to a force sensor 14. The second piston divides the rodless chamber of the master cylinder into a first oil chamber 16 and a second oil chamber 18, with the first oil chamber 16 being located between the first piston and the second piston.

The oil pump 8 is connected with the motor 9, the inlet of the oil pump 8 is connected with the oil tank 10 through an oil inlet pipe, the outlet of the oil pump 8 is connected with the inlet of the check valve 6 through a pipeline, the outlet of the check valve 6 is connected with the first oil liquid cavity 16 and the second oil liquid cavity 18 through two branch pipes respectively, a first high-speed switch valve is arranged on a branch pipe connected with the second oil liquid cavity 18, the outlet of the check valve 6 is connected with the oil inlet pipe through another branch pipe, and a second high-speed switch valve 7 is arranged on the other branch pipe. The first stopper rod 20 is located in a rod chamber of the master cylinder to restrict the first piston. The second stopper rod 19 is located in the first oil chamber and limits the second piston.

As shown in fig. 2, the control method for ABS road feel compensation and stroke analog coupling of the braking system of the present invention includes the following steps:

1) before braking, electricityThe oil pump 8 is driven by the machine 9 to operate, the first high-speed switch valve 5 is powered on, and the second high-speed switch valve 7 is powered off, so that the second oil piston cavity 16 and the third oil piston cavity 18 keep the initial pressure P₁After pressure maintaining, the first high-speed switch valve 5 is powered off, the second high-speed switch valve 7 is powered off, and the motor 9 stops running.

Initial pressure P₁The calculation formula of (2) is as follows:

in the formula: d represents the diameter of the second oil piston chamber 16; i represents a lever ratio of the brake pedal 11; f_maxRepresenting the maximum pedal force of the braking system at maximum deceleration in comfort, economy and sport modes.

2) When the brake pedal is stepped on, the ABS road feeling and stroke simulation coupling controller 4 inquires the target pedal stroke at the moment according to the force sensor value, the target pedal force and the pedal stroke Map, then calculates the volume discharge amount of the first oil liquid cavity 16, and controls the second high-speed switch valve 7 to be electrified, the motor 9 to be not operated and the first high-speed switch valve 5 to be powered off until the volume discharge amount of the first oil liquid cavity 16 is reached, and controls the second high-speed switch valve 7 to be powered off, the motor 9 to be not operated and the first high-speed switch valve 5 to be powered off.

The Map of the target pedal force and pedal stroke Map is related to the current braking mode of the automobile, and is divided into a comfort mode, an economy mode, a sport mode and the like, but the Map of the target pedal force and pedal stroke Map in each mode is fixed. Target pedal travel X_tBoth of which may be expressed as a functional expression of the target pedal force F, i.e., X_tλ f (f), λ represents a mapping proportionality coefficient between the target pedal force and the pedal stroke in the braking mode.

3) The ABS road feel and stroke simulation coupling controller 4 receives wheel slip rate signals from the CAN bus 3 in real time, if the wheel slip rate signals are larger than the highest slip rate value, ABS road feel adjusting time is calculated, the first high-speed switch valve and the second high-speed switch valve are alternately powered on or powered off according to the ABS road feel adjusting time value, and the motor is controlled to run, so that the volume of the second oil liquid cavity is reduced or increased until the wheel slip rate signals are smaller than the highest slip rate value. And if the wheel slip rate signal is less than the highest slip rate value, returning to the step 2).

When the volume of the second oil liquid cavity is reduced or increased, the judgment is carried out according to the odd number and the even number of the adjusting times, and when the adjusting times are odd numbers, the first high-speed switch valve and the second high-speed switch valve are electrified to control the motor not to run; when the adjusting times is even, the first high-speed switch valve is controlled to be powered on, the second high-speed switch valve is controlled to be powered off, and the motor runs.

The calculation formula of the ABS road feel adjusting time t is as follows:

t＝t₁-t₂

in the formula, t₁The time when the lowest slip value appears at the current moment in the wheel slip rate signal is taken as the time; t is t₂The time at which the highest slip value occurs at the next instant in the wheel slip rate signal.

4) And when the brake pedal is released, the ABS road feel and stroke simulation coupling controller inquires corresponding target pedal stroke according to the force sensor value and the target pedal force and pedal stroke Map, calculates the volume increment of the first oil liquid cavity, and then controls the motor to run and the first high-speed switch valve and the second high-speed switch valve to be powered off until the volume increment of the first oil liquid cavity is reached, and controls the motor to stop running and the first high-speed switch valve and the second high-speed switch valve to be powered off.

In step 2) and step 4), the volume discharge amount Δ Q of the first oil chamber 16₁And delta Δ Q₂The calculation formula of (a) is as follows:

in the formula x_i、x_i-1Representing the target pedal stroke at the present time and the previous time, respectively.