CN101480946B - Wheel load-based type intelligent sensing wheel brake performance monitoring methods - Google Patents

Abstract

The invention discloses a method for monitoring wheel braking performance based on wheel-mounted intelligent sensing. By installing an intelligent sensing module on the hub equatorial plane of each wheel of a motor vehicle and installing an intelligent sensing unit on the vehicle body, the sensing signal is passed through the signal Adjustment, digitization, attitude algorithm, and braking algorithm calculate the main braking performance parameters of the wheels. The main braking performance parameters of the wheels monitored by this method include: wheel slip rate, wheel road adhesion coefficient, wheel braking force, wheel braking Dynamic deceleration, etc.; this method can monitor and actively evaluate the safety status of motor vehicles through multi-sensor data fusion and analysis of the above parameters, which is beneficial to avoid and reduce the occurrence of traffic accidents.

Description

A method for monitoring wheel braking performance based on wheel-loaded intelligent sensor

technical field

The invention relates to the field of monitoring the safe running state of motor vehicles, in particular to a monitoring method for monitoring the real-time status of the wheel braking performance of the motor vehicle in the form process.

Background technique

Motor vehicle operation safety status monitoring technology is the main means to ensure the safe driving of motor vehicles, and it is also the inevitable trend of the development of motor vehicle operation safety detection technology. Use motor vehicle operation safety status monitoring technology to dynamically monitor motor vehicle operation safety status and operating indicators, discover and prevent motor vehicle failures in a timely manner, develop a safety monitoring network system integrating monitoring, control, management and decision-making, and ensure the safe operation of motor vehicles It is of great significance; it is a major social public welfare technical work related to the safety of the country and people's lives and properties, it is an important technical support to ensure the safety of motor vehicles, and it is a very important technical guarantee for the safe operation of motor vehicles by government management departments ; It can not only improve the technical support ability of safe operation of motor vehicles and reduce traffic accidents, but also has great significance for promoting the development of motor vehicle industry and transportation.

Motor vehicle operation safety status monitoring mainly includes monitoring motor vehicle (body, wheel) motion attitude parameters, dynamic load parameters, and braking performance parameters. Braking performance is the most important technical index for evaluating motor vehicles and one of the basic items for vehicle safety testing. During the operation of a motor vehicle, there will be working conditions such as braking, acceleration, steering, and straight-line driving. The wheel braking performance parameters that reflect the safety status or trend of motor vehicle operation mainly include: wheel slip rate, wheel road surface adhesion coefficient, and wheel braking performance. Braking force, wheel braking deceleration. By monitoring the braking performance of the wheels, more direct, more real and richer information on the safe operation of motor vehicles can be obtained. By monitoring the braking performance of the wheels, the braking performance of the motor vehicle can be comprehensively evaluated: the braking force of the wheel braking performance and the difference between the braking force of the front and rear axles, the left and right wheels can measure the braking force of the wheel brake and the coefficient of adhesion on the road surface, and the balance of the braking force of the wheel brake. The parameters of the state; the wheel slip rate is a parameter that can measure the best braking state of the wheel anti-lock braking system, and the wheel braking deceleration is a parameter that can measure the braking force of the wheel brake, which is very important for preventing motor vehicle braking performance failures. have a decisive influence.

At present, the monitoring of wheel braking performance is mainly through the monitoring of a single index of wheel braking deceleration, and it has not yet been able to effectively monitor parameters such as wheel slip rate, wheel road adhesion coefficient, and wheel braking force, so that it cannot be fully evaluated. and predict the braking performance of motor vehicles (including the braking performance of anti-lock brake ABS of motor vehicles); the detection and evaluation of the braking performance of motor vehicles mainly relies on regular safety inspections, and the real-time monitoring of the braking performance of motor vehicles has not been carried out; at the same time , the monitoring of the wheel braking deceleration parameters is to directly use the wheel speed sensor to measure the wheel speed, and the parameters measured by the wheel speed sensor have not yet been evaluated.

Contents of the invention

In order to solve the above-mentioned problems and defects, the present invention provides a method for monitoring wheel braking performance based on wheel-mounted intelligent sensors.

The present invention is achieved through the following technical solutions:

A wheel-mounted intelligent sensor-based wheel braking performance monitoring method involved in the present invention includes:

Perceive the three-dimensional acceleration of the wheel and the body through the intelligent sensing module;

Obtaining a three-dimensional acceleration value according to the three-dimensional acceleration signal output by the intelligent sensing module;

Using at least one acceleration parameter in the three-dimensional acceleration of the wheel to obtain the vertical acceleration and forward speed of the wheel through an attitude algorithm, and using at least one acceleration parameter in the three-dimensional acceleration of the vehicle body to obtain the longitudinal velocity of the vehicle body through an attitude algorithm;

Obtaining the wheel slip rate by calculating the slip rate according to at least one parameter among the longitudinal speed of the vehicle body and the forward speed of the wheel;

Obtain the wheel road surface adhesion coefficient through the wheel vertical acceleration parameter through the adhesion coefficient;

The wheel braking force is obtained by calculating at least one parameter of the wheel road surface adhesion system and the wheel dynamic load parameter and calculating the wheel braking force.

The method also includes:

The three-dimensional acceleration signal of the wheel is converted from analog to digital, and then the three-dimensional acceleration value of the installation point of the wheel intelligent sensor module is obtained through temperature compensation processing and interpolation decoupling processing, and the wheel speed is calculated;

The wheel braking deceleration is calculated according to the wheel speed parameters.

Fusion and analysis of wheel braking performance parameters: wheel slip rate, wheel road surface adhesion coefficient, wheel braking force and wheel braking deceleration to judge the working status of the intelligent sensing module and obtain the change trend of wheel braking performance .

The three-dimensional acceleration of the wheel includes tangential acceleration, lateral acceleration and centripetal acceleration; the three-dimensional acceleration of the vehicle body includes longitudinal acceleration, lateral acceleration and vertical acceleration.

The intelligent sensing module is arranged on the surface of the equatorial plane of the wheel hub.

The beneficial effects of the technical solution provided by the invention are:

1. By applying MEMS gyro-less strapdown micro-inertial measurement technology to measure wheel braking performance, real-time monitoring of motor vehicle wheel braking performance at different operating speeds is realized;

2. The braking force of the wheel and the difference between the braking force of the front and rear axles and the left and right wheels in the wheel braking performance parameters can measure the braking force of the wheel brake and the road adhesion coefficient, the balance state of the braking force of the wheel brake, and the wheel slip rate can measure the anti-lock braking of the vehicle The best braking state of the braking system, the deceleration of the wheel braking measures the braking force of the wheel brakes, and the overall evaluation of the braking performance of the motor vehicle is realized through the monitoring and analysis of the above braking performance parameters of the wheels;

3. Analyze and compare the wheel braking performance data with its historical data through the analysis and prediction program, obtain the trend of wheel braking performance, increase the prediction function of wheel braking performance, form a complete and relatively independent measurement platform, and be able to provide The unified data interface mode is available for relevant government management departments to apply.

Description of drawings

Fig. 1 is the flow chart of the wheel braking performance monitoring method based on the wheel-mounted intelligent sensor of the present invention;

Fig. 2 shows the installation diagram of the wheel-mounted intelligent sensor wheel braking performance measurement module involved in the present invention in a side view of the wheel;

Fig. 3 is a schematic view showing the installation of the wheel-mounted intelligent sensor wheel braking performance measurement module involved in the present invention in a top view of the wheel;

Fig. 4 shows the installation diagram of the wheel-mounted intelligent sensor wheel braking performance measurement module involved in the present invention with a front view of the wheel;

5 is an overall layout diagram of the wheel-mounted intelligent sensor wheel braking performance monitoring system involved in the present invention;

6 is a schematic diagram of the hardware structure of the wheel-mounted intelligent sensor wheel braking performance monitoring system of the present invention;

Fig. 7 respectively shows the curves of centripetal, tangential and lateral acceleration at a specified point of a tire monitored by the intelligent sensing module of Fig. 1 .

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the implementation of the present invention will be further described in detail below in conjunction with the accompanying drawings:

This embodiment provides a method for monitoring wheel braking performance based on wheel-mounted intelligent sensors.

Referring to Figure 1, the method comprises the following steps:

In step 101, the intelligent sensing unit perceives the three-dimensional acceleration of the wheels and the vehicle body.

The three-dimensional acceleration of the wheel includes: tangential acceleration, lateral acceleration and centripetal acceleration; the three-dimensional acceleration of the body includes: longitudinal acceleration, lateral acceleration and vertical acceleration.

Step 102 performs filtering, digital conversion and temperature compensation on the three-dimensional acceleration signals of the wheels and the vehicle body.

The tangential acceleration, lateral acceleration and centripetal acceleration output by the wheel intelligent sensor unit and the analog signals in the four channels of tire internal temperature are conditioned, A/D converted into digital signals, and then obtained through temperature compensation processing and interpolation decoupling processing. More accurate three-dimensional acceleration parameters at the installation point of the wheel intelligent sensing unit on the surface of the wheel hub (step 103).

Step 104 calculates and obtains the relative acceleration of the wheels and the vehicle body through an attitude algorithm or a braking algorithm according to the three-dimensional acceleration parameters.

The relevant acceleration obtained includes wheel vertical acceleration, wheel forward speed, vehicle body longitudinal speed, wheel slip rate, wheel road surface adhesion coefficient, wheel braking force and wheel braking deceleration, and the wheel vertical acceleration and wheel forward speed are based on the cut At least one parameter in the acceleration, lateral acceleration and centripetal acceleration is obtained through the attitude algorithm; the longitudinal velocity of the vehicle body is obtained through the attitude algorithm according to at least one parameter in the longitudinal acceleration, the lateral acceleration and the vertical acceleration; The wheel slip rate is obtained by calculating the slip rate according to at least one parameter of the vehicle body longitudinal speed and the wheel forward speed parameters; the wheel road surface adhesion coefficient is obtained by calculating the adhesion coefficient according to the wheel vertical acceleration parameters; using the adhesion coefficient parameter and at least one parameter among the wheel dynamic load parameters to obtain the wheel braking force through calculation of the wheel braking force.

Step 105 Braking performance parameters.

Step 106 fused and analyzed the braking performance data to obtain the changing trend of the braking performance of the wheels.

Braking performance data include wheel slip rate, wheel road adhesion coefficient, wheel braking force and wheel braking deceleration, etc.

Step 107 analyzes and predicts the change trend of the obtained wheel braking performance.

Step 108 judges the working condition of the intelligent sensing unit according to the fusion of the braking performance parameters of each wheel and the vehicle body.

See Figure 2, Figure 3, and Figure 4: The wheel braking performance intelligent sensing module is installed on the surface of the equatorial surface of the wheel hub. The installation requirements of the wheel intelligent sensing module: the three sensitive axes of the acceleration sensor, X axis, Y axis, The Z axis points to the tangential direction of the hub, the lateral direction of the hub, and the axis of the hub respectively; the coordinate system Oxyz is an orthogonal right-handed coordinate system.

See Fig. 5: It is the overall layout diagram of the system adopted by the wheel-mounted intelligent sensor wheel braking performance monitoring method according to the present invention, including the wheel 1, the wheel intelligent sensor module 2, and the central control module 3 in the vehicle. Wherein the wheel intelligent sensing module is installed on the equatorial surface of the hub of each wheel, and the in-vehicle central control module 3 is installed in the vehicle; the two-way communication is realized between the wheel intelligent sensing module 2 and the in-vehicle central control module 3 through radio frequency.

Referring to Fig. 6, the hardware system based on the wheel-mounted wheel braking performance monitoring method involved in the present invention includes a wheel intelligent sensor module 2 installed in each wheel and a car central control module 3 installed in the car; (1 ) The wheel intelligent sensing module 2 includes a first gyro-free inertial measurement unit 2a, a conditioning unit 2b, a wireless microcontroller 2c and a first power supply 2d; the first gyro-free inertial measurement unit 2a includes a three-axis acceleration sensor 21a and a temperature sensor 22a The three-axis acceleration sensor 21a and the temperature sensor 22a output analog signals, and the first gyro-free inertial measurement unit 2a is electrically connected with the conditioning unit 2b; the conditioning unit 2b is used to filter and regulate the input acceleration and temperature signals, and the conditioning The unit 2b is connected with the wireless single-chip microcomputer 2c, and the signal is an analog signal; the self-test signal of the wireless single-chip microcomputer 2c is connected with the three-axis acceleration sensor, and is used to check whether the three-axis acceleration sensor 21a is working normally; the wireless single-chip microcomputer 2c integrates a wireless transceiver circuit and The single-chip microcomputer is used for sensing and collecting, calculating and realizing the two-way communication function with the central control module 2 in the vehicle; the first power supply 2d is to provide a DC power supply for the first gyro-free inertial measurement unit 2a, the conditioning unit 2b and the wireless single-chip microcomputer 2c; Among them, the three-axis acceleration sensor 21a of the first gyro-free inertial measurement unit 2a is composed of a two-axis acceleration sensor ADXL323 and a single-axis acceleration sensor ADXL193, and the wireless single-chip microcomputer 2c adopts CC2510F32; (2) the central control module 3 in the car includes Wireless single-chip microcomputer 3a, vehicle body intelligent inertial measurement unit 3b, second power supply 3c, ARM processor 3d and human-computer interaction unit 3e; the wireless single-chip microcomputer 3a realizes the communication function with the wheel intelligent sensor module, and interacts with the ARM processor 3d through digital signals Connect; the second non-gyroscope inertial measurement unit 3b is connected with the ARM processor 3d, and the signal is a digital signal; the second power supply 3c is a wireless single-chip microcomputer 3a, a vehicle body intelligent inertial measurement unit 3b, an ARM processor 3d and a human-computer interaction unit 3e DC power supply is provided; the human-computer interaction unit 3e is composed of a liquid crystal screen 31e, a touch screen 32e, a buzzer 33e, and a CAN interface 34e; the liquid crystal screen 31e is used to output and display the output display information of the ARM processor 3d, including wheel dynamic load parameters, status and other parameters; the touch screen 32e is used to set parameters and query data; the buzzer 33e is used to send an alarm driven by the ARM processor 3d when a failure occurs; the CAN interface 34e is used to provide other CAN devices to access the interface of the central control module 3d in the car; Among them, the wireless single-chip microcomputer 3a (2c) adopts CC2510F32.

Its working process is: the tangential acceleration, lateral acceleration, centripetal acceleration, and temperature analog signals output by the gyro-less strapdown micro-inertial measurement unit 2a are conditioned by the conditioning unit 2b, and then converted into digital by the ADC peripheral of the wireless single-chip microcomputer 2c. The signal is provided to the CPU access of the wireless single-chip microcomputer 2c in an interrupt trigger mode; the wireless single-chip microcomputer 2c can self-check the acceleration sensor by driving the self-test signal when necessary; the microprocessor in the wireless single-chip microcomputer 7 carries out digital filtering and compensation for the signal Calculate the three-dimensional acceleration in the wheel motion attitude; including: tangential acceleration, lateral acceleration, and centripetal acceleration, which characterize the state of any instantaneous three-dimensional acceleration of the wheel, and the centripetal of a specified point of a tire monitored by the intelligent sensor module , tangential and lateral acceleration curves (referring to Fig. 7); the wireless single-chip microcomputer 3a that data transmission is exported to the central processing module 2 in the car by the wireless transceiver circuit inside the wireless single-chip 2c, simultaneously by the wireless transceiver 2c inside the wireless single-chip The circuit can also receive the commands sent by the central processing module 2 in the car through the wireless single-chip microcomputer 9; the tasks of the central processing module 3 in the car: 1. receive the body posture information from the intelligent inertial measurement unit 3b of the vehicle body; The data of the wheel intelligent sensing module 2 sends commands to the wheel intelligent sensing module 1 through the wireless single-chip microcomputer 9 when necessary; the microprocessor in the wireless single-chip microcomputer 3a is to the three-dimensional acceleration in the received wheel motion attitude, including: tangential acceleration , lateral acceleration, and centripetal acceleration to calculate the signal speed to obtain the forward speed and lateral speed of the wheel, which characterizes the state of any instantaneous speed of the wheel; Acceleration and speed data, the braking performance parameters of the wheel are obtained through attitude calculation and braking calculation, which include: wheel slip rate, wheel road surface adhesion coefficient, wheel braking force, wheel braking deceleration; ④ For the above wheel braking Dynamic performance data for active safety evaluation and trend prediction; ⑤ data fusion and analysis of wheel braking performance data and vehicle body braking performance data in order to judge whether the wheel intelligent sensor module 2 is working normally, and predict the wheel braking performance Change trend; ⑥ output and display wheel braking performance information, evaluation level, trend prediction information, etc. by controlling the LCD screen 31e; ⑦ process the interruption triggered by the touch screen 32e and perform operations such as parameter setting and historical query; ⑧ use digital signals when abnormalities occur Drive the buzzer 33e to make a buzzer warning; 9. Establish an electronic data table for storing relevant braking performance data and historical data for other CAN bus external devices to access through the CAN interface 34e.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention.

Claims (3)

1. A method for monitoring wheel braking performance based on wheel-loaded intelligent sensors, characterized in that the method comprises: Perceive the three-dimensional acceleration of the wheel and the body through the intelligent sensing module; Obtaining a three-dimensional acceleration value according to the three-dimensional acceleration signal output by the intelligent sensing module; Use the three-dimensional acceleration of the wheel to obtain the vertical acceleration and forward speed of the wheel through the attitude algorithm, and use the three-dimensional acceleration of the vehicle body to obtain the longitudinal velocity of the vehicle body through the attitude algorithm; Calculate the wheel slip rate according to the longitudinal speed of the vehicle body and the forward speed of the wheel; Obtain the wheel-road adhesion coefficient through the vertical acceleration of the wheel; The wheel braking force is obtained by calculating the wheel-road adhesion coefficient and wheel dynamic load; The three-dimensional acceleration signal of the wheel is converted from analog to digital, and then the three-dimensional acceleration value of the installation point of the wheel intelligent sensor module is obtained through temperature compensation processing and interpolation decoupling processing, and the wheel speed is calculated; Calculate the wheel braking deceleration according to the wheel speed parameters; Fusion and analysis of wheel braking performance parameters: wheel slip rate, wheel road surface adhesion coefficient, wheel braking force and wheel braking deceleration to judge the working status of the intelligent sensing module and obtain the change trend of wheel braking performance . 2. The method for monitoring wheel braking performance based on wheel-mounted intelligent sensors according to claim 1, wherein the three-dimensional acceleration of the wheel comprises tangential acceleration, lateral acceleration and centripetal acceleration; the three-dimensional acceleration of the vehicle body Including longitudinal acceleration, lateral acceleration and vertical acceleration. 3 . The method for monitoring wheel braking performance based on wheel-mounted intelligent sensing according to claim 1 , wherein the intelligent sensing module is arranged on the surface of the equatorial plane of the wheel hub. 4 .

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