CN108556832A - A kind of smart electronics power-assisted braking arrangement and its working method - Google Patents

Abstract

The invention discloses an intelligent electronic power-assisted braking device and its working method, comprising a brake master cylinder assembly, an electronic booster assembly and a brake pedal assembly, wherein the electronic booster assembly includes an electronic control unit, a motor, a driving gear, a slave Moving gear, planetary roller screw mechanism, etc. The electronic control unit of the device collects the pressure signal of the brake master cylinder, the displacement signal and speed signal of the brake pedal, and the wheel speed signal of the wheel, and calculates the current output to the motor. The torque of the motor is decelerated and increased by the driving gear, driven gear, and planetary roller screw mechanism, and then converted into the translational thrust of the screw, which is superimposed with the thrust directly applied by the driver to the screw through the brake pedal to push the master cylinder. The pushrod and master cylinder piston generate brake pressure. Moreover, the electronic control unit enters different power-assisted braking modes according to the fault self-diagnosis results to ensure the driving safety of the vehicle. The invention has the advantages of compact structure, reliable operation and stable braking, and is suitable for application in many vehicle models.

Description

An intelligent electronic power-assisted braking device and its working method

technical field

The invention relates to the field of automobile braking, in particular to an intelligent electronic power-assisted braking device and a working method thereof.

Background technique

In recent years, the application of electric vehicles and hybrid vehicles has become more and more widespread. When they have no engine or are in pure electric mode and the engine is not working, the traditional vacuum brake booster will lose its vacuum source, and the braking ability of the vehicle will be affected. limit. In addition, the vacuum booster is prone to leakage, resulting in reduced braking efficiency, weak fault self-adjustment ability, and difficult to guarantee the safety of automobile braking. Moreover, the vacuum pump is always in working state when the automobile is running, and the energy consumption is high. Therefore, it is necessary to propose an intelligent booster device with wide applicability, high braking efficiency, energy saving and high braking safety.

At present, there have been many researches on automobile power-assisted braking technology. Among them, the ibooster product developed by Bosch has been widely used in many models. This type of product adopts two-stage transmission of worm gear and rack and pinion, and converts the torque output by the motor into the main braking force. The power boosting of the cylinder push rod has low efficiency of the transmission device, and the space required for the structure is large. A power-assisted braking device and braking method for pure electric vehicles proposed by Wang Wenjiang (Patent No. CN201710112898.5), which shares a power source with the steering system, and separates a branch from the high-pressure oil pump of the steering system to the brake fluid. In the system, energy consumption is reduced, and the pressure of the brake fluid is high and stable, which improves the ease of operation of the brake system and ensures the reliability of the brake system. However, the structural layout of the booster is complicated. Since the braking pressure comes from the steering system, when the steering system fails, it will directly affect the braking system, and the driving safety will be affected. Zhejiang Libang Hexin Intelligent Braking System Co., Ltd. has designed an electronic brake booster (patent number CN201610963311.7). The rotating driving motion is converted into translational output motion for manipulating the braking system, which effectively reduces the cost and increases the transmission torque, and the threaded screw has a self-locking function. During the process of maintaining the braking force, the motor Even if the power is cut off, the threaded screw can be fixed and continue to brake. However, the device cannot adjust the braking force according to the needs of the vehicle in real time, and has poor intelligence, weak self-adjustment ability for faults, and unstable braking ability. Miao Huibin designed a brake booster device and its braking method (Patent No. CN201710136939.4). This device omits the vacuum pump, uses the motor as the brake booster source, collects the braking information of the brake pedal through the sensor, and The electric signal is sent to the electronic control unit, and the electronic control unit generates a booster signal according to the braking information, and sends the booster signal to the motor, and brakes with the booster brake actuator through the transmission device, which does not rely on the vacuum source, shortens the braking distance, and improves Safety, strong braking force, long maintenance time, energy saving, safe and reliable. However, this device does not clearly point out the specific transmission mode of the transmission device, and only collecting the braking information of the pedal will make the judgment of the braking state inaccurate and the adjustment of the braking state not flexible enough.

To sum up, the automobile brake boosting device in the prior art has the disadvantages of complex structure and inflexible braking method.

Contents of the invention

The invention provides an intelligent electronic power-assisted braking device and a working method thereof, which can provide a braking device with compact structure, reliable braking boost and flexible braking method, and is suitable for application in traditional vehicles and new energy vehicles.

To achieve the above object, the present invention adopts the following technical solutions:

An intelligent electronic power-assisted braking device includes: a brake master cylinder assembly, an electronic booster assembly and a brake pedal assembly.

The electronic power assist component includes: an electronic control unit, a motor, an output shaft, a driving gear, a driven gear, and a planetary roller screw mechanism. The output shaft of the motor drives the driving gear, and the driving gear drives the driven gear.

The inner ring of the driven gear is rigidly connected with the inner ring gear, and the inner side of the inner ring gear meshes with the planetary roller screw mechanism.

The planetary roller screw mechanism includes an inner ring gear, a gear roller and a lead screw. The inner ring gear meshes with a planetary gear train composed of multiple gear rollers, and the planetary gear train composed of multiple gear rollers meshes with the lead screw. The rotation of the gear rollers is converted into translational motion of the lead screw. One end of the lead screw is connected to the brake pedal assembly, and the other end is connected to the brake master cylinder.

Further, the brake master cylinder assembly includes an oil cup, a brake master cylinder, a master cylinder piston, a master cylinder push rod and a pressure sensor. The screw rod, the master cylinder push rod, the master cylinder piston and the brake master cylinder are connected in sequence. The brake master cylinder is also equipped with an oil cup and a pressure sensor, and the pressure sensor is used to collect the pressure signal in the brake master cylinder.

Further, the brake pedal assembly includes: a brake pedal, a pedal stroke sensor and an angular velocity sensor. The screw rod is connected to the brake pedal, and a pedal stroke sensor and an angular velocity sensor are installed on the brake pedal to collect displacement signals and speed signals of the brake pedal.

A working method of an intelligent electronic power-assisted braking device, the flowchart of which is shown in Figure 2, comprising the following steps:

S1. The electronic control unit collects the pressure signal in the brake master cylinder through the pressure sensor, the displacement signal and speed signal of the brake pedal through the pedal stroke sensor and the angular velocity sensor, and the wheel speed signal of each wheel through the wheel speed sensor.

S2. The electronic control unit performs fault self-diagnosis according to the pressure signal, displacement signal, speed signal, and wheel speed signal.

S31. The fault self-diagnosis result shows that there is no fault, go to S311;

S311. The electronic control unit identifies the driver's braking intention and calculates the theoretical pressure value of the brake master cylinder according to the displacement signal and the speed signal;

S312. The electronic control unit calculates the input current of the motor according to the pressure signal, the theoretical value of the pressure signal of the brake master cylinder, and the wheel speed signal, and transmits the input current to the motor;

S313. The electronic control unit sends instructions to control the speed and torque of the motor, and the motor drives the planetary roller screw mechanism to provide braking compensation; the motor drives the driving gear to rotate through the output shaft, and the driving gear meshes with the driven gear to drive the driven gear and The ring gear rotates. The inner ring gear drives the gear roller to rotate, and the screw equivalent to the sun gear of the planetary reducer does not rotate in the circumferential direction, which can be regarded as fixed. Therefore, the torque of the motor is decelerated by the planetary roller screw mechanism and then increased by the gear roller. output. Since the planetary gear train composed of multiple gear rollers meshes with the lead screw, the rotation of the gear rollers can be converted into the translational motion of the lead screw, that is, the output torque of the gear roller 8 is converted into the thrust of the lead screw, which is consistent with the driver through The brake pedal is directly applied to the lead screw to superimpose the thrust, pushing the master cylinder push rod and the master cylinder piston to generate brake pressure.

S32. The fault self-diagnosis result shows that the pressure sensor is faulty, and proceeds to S321;

S321. The electronic control unit calculates a theoretical value of vehicle deceleration according to the displacement signal and the speed signal;

S322. The electronic control unit calculates the input current of the motor according to the wheel speed signal and the theoretical value of vehicle deceleration;

S323. The electronic control unit sends instructions to control the speed and torque of the motor. The motor drives the planetary roller screw mechanism to provide braking compensation, and the thrust of the screw is output through the output shaft, driving gear, driven gear and planetary roller screw mechanism. , superimposed with the thrust directly applied by the driver to the lead screw through the brake pedal, pushing the master cylinder push rod and the master cylinder piston to generate brake pressure.

S33. The fault self-diagnosis result shows that there is a fault in the pedal stroke sensor or the angular velocity sensor, go to S331;

S331. The electronic control unit estimates the theoretical pressure value of the brake master cylinder according to the data collected by the non-faulty pedal stroke sensor or the angular velocity sensor;

S332. The electronic control unit calculates the input current of the motor according to the pressure signal, the theoretical value of the pressure signal of the brake master cylinder, and the wheel speed signal;

S333. The electronic control unit sends instructions to control the speed and torque of the motor; the motor drives the planetary roller screw mechanism to provide braking compensation, and the thrust of the screw is output through the output shaft, driving gear, driven gear and planetary roller screw mechanism , superimposed with the thrust directly applied by the driver to the lead screw through the brake pedal, pushing the master cylinder push rod and the master cylinder piston to generate brake pressure.

S34. The fault self-diagnosis result shows other faults, and the electronic control unit cuts off the power supply of the motor and stops working.

The beneficial effects of the present invention are:

The electronic booster assembly of the present invention adopts two-stage transmission, which increases the rotation ratio. Compared with the ordinary reducer, the size of the reducer is reduced under the same braking force, and the first-stage driven gear and the planetary The rigid connection of the inner ring gear of the roller screw mechanism further reduces the radial size of the reducer, making the structure of the electronic booster assembly compact; moreover, the working method of the device in the present invention adopts the idea of fault-tolerant processing, even if When the sensor fails, it can still effectively provide braking boost, the braking force is reliable and the braking method is flexible; in summary, the present invention has compact structure, reliable braking boost, and flexible braking method, and can be widely applied to traditional fuel vehicles and new vehicles. energy car.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Fig. 1 is a schematic structural view of an intelligent electronic power-assisted braking device in an embodiment;

Fig. 2 is a flowchart of the working method in the embodiment.

Among them, 1-oil cup, 2-brake master cylinder, 3-master cylinder piston, 4-master cylinder push rod, 5-return spring, 6-planetary roller screw mechanism, 7-internal gear, 8- Gear roller, 9-driven gear, 10-lead screw, 11-brake pedal, 12-pressure sensor, 13-electronic control unit, 14-motor, 15-output shaft, 16-driving gear, 17-electronic power assist Device housing, 18-pedal stroke sensor, 19-angular velocity sensor.

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with specific embodiments.

An embodiment of the present invention provides an intelligent electronic power-assisted braking device, as shown in FIG. 1 , comprising: a brake master cylinder assembly, an electronic booster assembly, and a brake pedal assembly, which are connected in sequence.

The brake master cylinder assembly includes: an oil cup 1 , a brake master cylinder 2 , a master cylinder piston 3 , a master cylinder push rod 4 and a pressure sensor 12 . The screw rod 10, the master cylinder push rod 4, the master cylinder piston 3 and the brake master cylinder 2 are sequentially connected, and the brake master cylinder 2 is also equipped with an oil cup 1 and a pressure sensor 12.

The electronic power assist assembly includes: an electronic control unit 13 , a motor 14 , an output shaft 15 , a driving gear 16 , a casing 17 , a driven gear 9 , a planetary roller screw mechanism 6 , and a return spring 5 . The screw rod 10 is inserted into the shell 17, runs through the planetary roller screw mechanism 6, and is connected with the other end of the master cylinder push rod 4, and the return spring 5 is installed under the handle of the master cylinder push rod 4, and the other end of the return spring 5 and the shell 17, used to return the push rod 4 of the master cylinder, and push the screw mandrel 10, thereby resetting the brake pedal 11.

The output shaft 15 of the motor 14 drives the driving gear 16 , and the driving gear 16 drives the driven gear 9 . The inner ring of the driven gear 9 is rigidly connected to the ring gear 7, and the inner side of the ring gear 7 meshes with the planetary roller screw mechanism 6. The planetary roller screw mechanism 6 includes an inner ring gear 7, a gear roller 8 and a lead screw 10, the inner ring gear 7 meshes with a planetary gear train composed of a plurality of gear rollers 8, and the planetary gear composed of a plurality of gear rollers 8 The system meshes with the lead screw 10 to convert the rotation of the gear roller 8 into the translation of the lead screw 10. One end of the lead screw 10 is connected to the brake pedal assembly, and the other end is connected to the brake master cylinder 2 .

The brake pedal assembly includes: a brake pedal 11, a pedal stroke sensor 18 and an angular velocity sensor 19, the screw mandrel 10 is connected to the brake pedal 11, and the pedal stroke sensor 18 and the angular velocity sensor 19 are installed on the brake pedal 11.

When the driver steps on the brake, the brake pedal 11 pushes the screw mandrel 10 , and the screw mandrel 10 further pushes the master cylinder push rod 4 . The pedal stroke sensor 18 and the angular velocity sensor 19 collect the motion parameters of the brake pedal 11, and the electronic control unit 13 calculates the brake booster value that needs to be supplemented in combination with the motion parameters, the pressure parameters of the master brake cylinder 2 and the wheel speed of the vehicle, thereby The motor 14 is controlled to perform braking force compensation. The motor 14 drives the planetary roller screw mechanism 6, and the braking force compensation is applied to the active push rod 4 through two-stage transmission. After the braking is completed, the master cylinder push rod 4 returns under the elastic force of the return spring 5, thereby pushing the brake pedal 11 to reset.

The present invention also provides a working method of an intelligent electronic power-assisted braking device, comprising the following steps:

S1. When the driver depresses the brake pedal 11, the electronic control unit 13 collects the pressure signal in the brake master cylinder 2 through the pressure sensor 12, and collects the displacement signal and the displacement signal of the brake pedal 11 through the pedal travel sensor 18 and the angular velocity sensor 19. The speed signal collects the wheel speed signal of each wheel through the wheel speed sensor.

S2. The electronic control unit 13 performs fault self-diagnosis according to the pressure signal, displacement signal, speed signal, and wheel speed signal.

S31. The fault self-diagnosis result shows that there is no fault, go to S311;

S311. The electronic control unit 13 identifies the driver's braking intention and calculates the theoretical pressure value of the brake master cylinder 2 according to the displacement signal and the speed signal;

S312. The electronic control unit 13 calculates the input current of the motor 14 according to the pressure signal, the theoretical value of the pressure signal of the brake master cylinder 2, and the wheel speed signal;

S313, the electronic control unit 13 sends an instruction to control the rotational speed and torque of the motor 14, and the motor 14 drives the planetary roller screw mechanism 6 to provide braking compensation. The motor 14 drives the driving gear 16 to rotate through the output shaft 15, and the driving gear 16 meshes with the driven gear 9 to drive the driven gear 9 and the inner ring gear 7 to rotate. The inner ring gear 7 drives the gear roller 8 to rotate, but the lead screw 10 equivalent to the sun gear of the planetary reducer does not rotate in the circumferential direction, which can be regarded as fixed, so the torque of the motor 14 is decelerated and increased by the planetary roller screw mechanism 6 Output by gear roller 8 afterward. Since the planetary gear train composed of multiple gear rollers 8 meshes with the lead screw 10, the rotation of the gear roller 8 can be converted into the translation of the lead screw 10, that is, the output torque of the gear roller 8 is converted into the thrust of the lead screw 10 , superimposed with the thrust directly applied by the driver to the lead screw 10 via the brake pedal 11, pushing the master cylinder push rod 4 and the master cylinder piston 3 to generate brake pressure.

S32. The fault self-diagnosis result shows that the pressure sensor is faulty, and proceeds to S321;

S321. The electronic control unit 13 calculates a theoretical value of vehicle deceleration according to the displacement signal and the speed signal;

S322. The electronic control unit 13 calculates the input current of the motor 14 according to the wheel speed signal and the theoretical value of vehicle deceleration;

S323, the electronic control unit 13 sends instructions to control the speed and torque of the motor 14, and the motor 14 drives the planetary roller screw mechanism 6 to provide braking compensation, through the output shaft 15, the driving gear 16, the driven gear 9 and the planetary roller wire The thrust of the lead screw 10 output by the lever mechanism 6 is superimposed with the thrust directly applied to the lead screw 10 by the driver through the brake pedal 11, and pushes the master cylinder push rod 4 and the master cylinder piston 3 to generate brake pressure.

S33. The fault self-diagnosis result shows that the pedal stroke sensor 18 or the angular velocity sensor 19 is faulty, and proceeds to S331;

S331. The electronic control unit 13 estimates the theoretical pressure value of the brake master cylinder 2 according to the data collected by the non-faulty pedal sensor 18 or the angular velocity sensor 19;

S332. The electronic control unit 13 calculates the input current of the motor 14 according to the pressure signal, the theoretical value of the pressure signal of the brake master cylinder 2, and the wheel speed signal;

S333, the electronic control unit 13 sends instructions to control the speed and torque of the motor 14, and the motor 14 drives the planetary roller screw mechanism 6 to provide braking compensation, through the output shaft 15, the driving gear 16, the driven gear 9 and the planetary roller wire The thrust of the lead screw 10 output by the lever mechanism 6 is superimposed with the thrust directly applied to the lead screw 10 by the driver through the brake pedal 11, and pushes the master cylinder push rod 4 and the master cylinder piston 3 to generate brake pressure.

S34. The fault self-diagnosis result shows other faults, and the electronic control unit 13 cuts off the power supply of the motor 14 to stop working. The planetary roller screw mechanism 6 is in a state of free movement and will not increase the motion load of the lead screw 10 . Now only rely on the driver to directly apply the thrust on the leading screw 10 through the brake pedal 11 to promote the master cylinder push rod 4 and the master cylinder piston 3 to generate part of the braking pressure and ensure the safety of the vehicle.

The beneficial effects of the present invention are:

(1) Compact structure, easy to arrange: the present invention adopts two-stage transmission, increases the transmission ratio, can appropriately reduce the size of the motor, the first-stage driven gear is rigidly connected with the inner ring gear of the planetary roller screw mechanism, and the diameter Small size, easy to arrange;

(2) Energy saving: The electronic power-assisted braking device of the present invention does not require a vacuum booster or an electronic power-assisted pump, and only provides power assist during braking, and can maximize the efficiency of braking energy recovery of electric vehicles;

(3) High reliability: the present invention uses a fault-tolerant processing method to ensure that the brake booster can be effectively provided when the sensor fails, and the mechanical structure can still provide braking force to ensure the safety of the car when the motor and other systems fail;

(4) Wide range of applications: the invention can be installed on traditional fuel vehicles and various new energy vehicles, and can also be installed on unmanned vehicles to realize the autonomous braking function.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (4)

1. a kind of smart electronics power-assisted braking arrangement, which is characterized in that including master cylinder component, electronics power-assisted device assembly and system Dynamic pedal assembly,

The electronics power-assisted component includes：Electronic control unit（13）, motor（14）, output shaft（15）, driving gear（16）, from Moving gear（9）, planet roller screw mechanism（6）；

Motor（14）Output shaft（15）Drive driving gear（16）, driving gear（16）Drive driven gear（9）；

Driven gear（9）Inner ring and ring gear（7）Rigid connection, ring gear（7）Inside and planet roller screw mechanism（6）It nibbles It closes；

Planet roller screw mechanism（6）Including ring gear（7）, gear roller（8）And leading screw（10）, ring gear（7）With multiple teeth Take turns roller（8）The planetary gear train of composition engages, multiple gear rollers（8）The planetary gear train and leading screw of composition（10）Engagement, by tooth Take turns roller（8）Rotation be converted into leading screw（10）Translation；

Leading screw（10）One end connects the brake pedal component, and the other end connects master cylinder（2）.

2. the apparatus according to claim 1, which is characterized in that the master cylinder component includes lubricating cup（1）, master cylinder （2）, master cylinder piston（3）, master cylinder push rod（4）And pressure sensor（12）,

Lead screw（10）, master cylinder push rod（4）, master cylinder piston（3）And master cylinder（2）It is sequentially connected, master cylinder（2）Also install Lubricating cup（1）And pressure sensor（12）.

3. the apparatus according to claim 1, which is characterized in that the brake pedal component includes：Brake pedal（11）, step on Plate stroke sensor（18）And angular-rate sensor（19）, lead screw（10）And brake pedal（11）Connection, brake pedal（11）On Pedal travel sensor is installed（18）And angular-rate sensor（19）.

4. a kind of working method of smart electronics power-assisted braking arrangement, which is characterized in that comprise the steps of：

S1, electronic control unit（13）Pass through pressure sensor（12）Acquire master cylinder（2）Interior pressure signal, passes through pedal Stroke sensor（18）And angular-rate sensor（19）Acquire brake pedal（11）Displacement signal and speed signal, pass through wheel speed Sensor acquires the wheel speed signal of each wheel；

S2, electronic control unit（13）According to the pressure signal, displacement signal, speed signal, wheel speed signal, failure is carried out certainly Diagnosis；

S31, fault self-diagnosis result show fault-free, until S311；

S311, electronic control unit（13）According to institute's displacement signal and speed signal, identification operator brake is intended to and calculates Master cylinder（2）Pressure theory value；

S312, electronic control unit（13）According to the pressure signal, master cylinder（2）Pressure signal theoretical value, the wheel Fast signal calculates motor（14）Input current；

S313, electronic control unit（13）Send instruction control motor（14）Rotating speed and torque；

S32, fault self-diagnosis result show pressure sensor（12）There are failures, until S321；

S321, electronic control unit（13）According to institute's displacement signal and speed signal, vehicle deceleration theoretical value is calculated；

S322, electronic control unit（13）According to the wheel speed signal and vehicle deceleration theoretical value, motor is calculated（14）It is defeated Enter electric current；

S323, electronic control unit（13）Send instruction control motor（14）Rotating speed and torque；

S33, fault self-diagnosis result show pedal travel sensor（18）Or angular-rate sensor（19）There are failures, until S331；

S331, electronic control unit（13）According to the pedal travel sensor of non-faulting（18）Or angular-rate sensor（19）Acquisition Data estimation master cylinder（2）Pressure theory value；

S332, electronic control unit（13）According to the pressure signal, master cylinder（2）Pressure signal theoretical value, the wheel Fast signal calculates motor（14）Input current；

S333, electronic control unit（13）Send instruction control motor（14）Rotating speed and torque；

S34, fault self-diagnosis result show other failures, electronic control unit（13）Cut off motor（14）Power supply is stopped.