Online monitoring device and method for end face runout of brake disc

Abstract

The invention relates to the field of vehicle chassis control systems, in particular to an online monitoring device and method for end face runout of a brake disc. Comprising the steps that firstly, the preset wheel speed of a wheel is set, the real-time wheel speed of the wheel is collected, then the real-time wheel speed is compared with the preset wheel speed, and if the real-time wheel speed is larger than the preset wheel speed, the second step is executed; secondly, the real-time clamping force of the friction plate on the brake disc and the instruction clamping force sent by a driver are collected, and the collected real-time clamping force is compared with the instruction clamping force; 3, collecting the times that the real-time clamping force is not equal to the instruction clamping force in unit time, and obtaining the error frequency; 4, the real-time wheel speed is compared with the error frequency, and whether the real-time wheel speed and the error frequency meet the multiple relation or not is judged; and 5, calculating the difference value between the real-time clamping force and the instruction clamping force, setting the difference value as a clamping force error, meanwhile, setting an error threshold value, comparing the clamping force error with the error threshold value, and if the clamping force error is greater than the error threshold value, triggering an alarm.

Description

Technical Field

[0001] The invention relates to the field of vehicle chassis control systems, and in particular to an online monitoring device and method for brake disc end face runout. Background Art

[0002] The brake disc is an important part of the automobile braking system. During the braking process, the friction between the brake disc and the friction pad is used to control the vehicle deceleration. If the thickness of the brake disc is different or the end face runout is too large, it will cause brake vibration and abnormal noise, seriously affecting the customer's driving experience and even causing safety risks.

[0003] The traditional method of detecting the end face runout of the brake disc is mainly to perform a one-time detection by equipment or manual methods during offline testing, and it is impossible to continuously monitor the brake disc runout caused by brake adhesion, debris intrusion, etc. during operation. In order to monitor the brake disc runout online, some car companies have made special improvements to the design of the brake disc and added sensors for monitoring, which will undoubtedly increase the cost and design difficulty. Therefore, the present invention has developed an online monitoring device and method for the end face runout of the brake disc. Summary of the invention

[0004] The purpose of the present invention is to provide an online monitoring device and method for brake disc end face runout, so as to solve the problem that the brake disc end face runout cannot be detected in real time in the prior art.

[0005] The technical solution of the present invention is: an online monitoring method for brake disc end face runout, comprising the following steps:

[0006] Step 1: Set the preset wheel speed of the wheel, collect the real-time wheel speed of the wheel, and then compare the real-time wheel speed with the preset wheel speed. If the real-time wheel speed is greater than the preset wheel speed, proceed to step 2.

[0007] Step 2: Collect the real-time clamping force of the friction plate on the brake disc and the command clamping force issued by the driver, and compare the collected real-time clamping force with the command clamping force. If they are not equal, proceed to step 3;

[0008] Step 3, collecting the number of times that the real-time clamping force is not equal to the command clamping force per unit time, and obtaining the error frequency;

[0009] Step 4: Compare the real-time wheel speed with the error frequency to determine whether the real-time wheel speed and the error frequency satisfy a multiple relationship, and the multiple is a fixed positive integer; if so, proceed to step 5;

[0010] Step 5: Calculate the difference between the real-time clamping force and the command clamping force and set it as the clamping force error. At the same time, set the error threshold, compare the clamping force error with the error threshold, and if the clamping force error is greater than the error threshold, trigger an alarm.

[0011] Preferably, the difference between the real-time clamping force and the command clamping force is set as an error value, and the clamping force error is subjected to fast Fourier decomposition to extract the main frequency and amplitude information of the harmonic component of the clamping force error.

[0012] Preferably, multiple real-time wheel speeds N1, N2...NC are collected in different time periods, and the error frequencies T1, T2...TC at the moments corresponding to N1, N2...NC are obtained; the corresponding N1 and T1, N2 and T2, NC and TC are compared in turn, and it is determined whether they satisfy the multiple relationship, and whether the multiple multiple relationships are the same and are any positive integers.

[0013] An online monitoring device for brake disc end face runout comprises a mechanical brake system and a control module system.

[0014] Preferably, the control module system includes a clamping force controller module, an end face runout calculation module, and an end face runout warning module;

[0015] The clamping force controller module includes a force sensor for real-time feedback of the clamping force;

[0016] The end face runout calculation module is used to judge the relationship between the error frequency and the wheel speed frequency to determine the magnitude of the clamping force jitter caused by the end face runout of the brake disc;

[0017] The end face runout warning module is used to determine whether the end face runout exceeds a threshold value, and if so, issue a vehicle warning.

[0018] Preferably, the mechanical brake system comprises: a motor, a motor output shaft, a force sensor, a lead screw, a lead screw nut, a friction plate and a brake disc;

[0019] The motor can provide rotational motion, drive the motor shaft and the lead screw to rotate, and then push the lead screw nut and the friction plate to move linearly, squeeze the brake disc, and generate braking force; the force sensor is fixed on the housing and contacts the lead screw stroke through the needle bearing, so as to be used for detecting the clamping force between the brake disc and the friction plate.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] The present application realizes real-time and accurate monitoring of the clamping force of the friction plate through a force sensor. By comparing the difference between the command clamping force and the real-time clamping force, the unevenness of the end face of the brake disc is reflected, thereby realizing online monitoring and efficient early warning of the end face runout of the brake disc, effectively avoiding a series of safety hazards and equipment failures caused by the end face runout of the brake disc, and greatly improving the safety and stability of the braking system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0023] Figure 1 It is a flow chart of an online monitoring method for brake disc end face runout according to the present invention;

[0024] Figure 2 This is a structural diagram of an online monitoring device for brake disc end face runout according to the present invention;

[0025] Among them: 1. Motor, 2. Force sensor, 3. Screw, 4. Screw nut, 5. Friction plate, 6. Brake disc. DETAILED DESCRIPTION

[0026] The present invention is further described in detail below in conjunction with specific embodiments:

[0027] like Figure 2 As shown, an online monitoring device for the end face runout of a brake disc comprises a mechanical brake system and a control module system, wherein the mechanical brake system comprises: a motor 1, a force sensor 2, a screw 3, a screw nut, a friction plate 5 and a brake disc 6. The motor 1 can provide a rotational motion, drive the motor 1 shaft and the screw 3 to rotate, and then push the screw nut 4 and the friction plate 5 to move linearly, squeeze the brake disc 6, and generate a braking force. The force sensor 2 is fixed on the housing, and contacts the screw 3 through a needle bearing, so as to realize the detection of the real-time clamping force between the brake disc 6 and the friction plate 5.

[0028] The control module system includes a clamping force controller module, an end face runout calculation module and an end face runout warning module.

[0029] The clamping force controller module includes a force sensor 2 , which is disposed between the friction plate 5 and the execution end of the motor 1 driving the friction plate 5 to operate, and is used for real-time feedback of the clamping force of the friction plate 5 on the brake disc 6 .

[0030] The end face runout calculation module is used to judge the relationship between the error frequency and the wheel speed frequency, so as to determine the magnitude of the clamping force jitter caused by the end face runout of the brake disc 6 .

[0031] The end face runout warning module is used to determine whether the end face runout exceeds a threshold value. If it exceeds the threshold value, a vehicle warning is issued.

[0032] The present application also provides an online monitoring method for brake disc end face runout, such as Figure 1 As shown, the following steps are included:

[0033] Step 1: Set the preset wheel speed of the wheel, collect the real-time wheel speed of the wheel, and then compare the real-time wheel speed with the preset wheel speed. If the real-time wheel speed is greater than the preset wheel speed, proceed to step 2.

[0034] Step 2: Collect the real-time clamping force of the friction plate 5 on the brake disc 6 and the command clamping force issued by the driver, and compare the collected real-time clamping force with the command clamping force. If they are not equal, proceed to step 3.

[0035] The command clamping force is the driving force applied by the motor 1 to the friction plate 5. When the real-time clamping force is not equal to the command clamping force, it proves that the driving force of the motor 1 on the friction plate 5 is not equal to the clamping force of the friction plate 5 on the brake disc 6, that is, it proves that the friction plate 5 has a jumping phenomenon. However, it cannot be determined whether the jumping phenomenon is caused by the uneven end surface of the brake disc 6. There may be other factors that cause the friction plate 5 to jump.

[0036] Step 3: Collect the number of times that the real-time clamping force is not equal to the command clamping force per unit time, and obtain the error frequency.

[0037] Step 4: Compare the real-time wheel speed with the error frequency to determine whether the error frequency and the real-time wheel speed satisfy a multiple relationship, and the multiple is a fixed positive integer. If satisfied, proceed to step 5. Specifically, collect multiple real-time wheel speeds N1, N2...NC in different time periods, and obtain T1, T2...TC of the error frequency at the corresponding N1, N2...NC moments respectively; compare the corresponding N1 with T1, N2 with T2, NC with TC in turn, and determine whether they satisfy a multiple relationship, and whether the multiple multiple relationships are the same and are any positive integers. If satisfied, it means that every time the wheel rotates one circle, the clamping force of the friction plate 5 will be abnormal for a fixed number of times, which is consistent with the situation that there is a defect on the end face of the brake disc 6 causing the clamping force of the friction plate 5 to be abnormal.

[0038] Step 5: Calculate the difference between the real-time clamping force and the command clamping force and set it as the clamping force error. At the same time, set the error threshold, compare the clamping force error with the error threshold, and if the clamping force error is greater than the error threshold, trigger an alarm.

[0039] Because the brake disc 6 cannot be kept absolutely flat in an ideal state during use, it is set that an early warning is issued only when the clamping force error exceeds the error threshold.

[0040] By performing fast Fourier decomposition on the clamping force error and extracting the main frequency and amplitude information of the harmonic component of the clamping force error, the number and degree of defects on the end surface of the brake disc 6 can be obtained.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention.

Claims

1. An online monitoring method for brake disc end face runout, characterized in that: The steps include: Step 1: Set the preset wheel speed of the wheel, collect the real-time wheel speed of the wheel, and then compare the real-time wheel speed with the preset wheel speed. If the real-time wheel speed is greater than the preset wheel speed, proceed to step 2. Step 2: Collect the real-time clamping force of the friction plate on the brake disc and the command clamping force issued by the driver, and compare the collected real-time clamping force with the command clamping force. If they are not equal, proceed to step 3; Step 3, collecting the number of times that the real-time clamping force is not equal to the command clamping force per unit time, and obtaining the error frequency; Step 4: compare the real-time wheel speed with the error frequency to determine whether the real-time wheel speed and the error frequency satisfy a multiple relationship, and the multiple is a fixed positive integer; if so, proceed to step 5; Step 5: Calculate the difference between the real-time clamping force and the command clamping force and set it as the clamping force error. At the same time, set the error threshold, compare the clamping force error with the error threshold, and if the clamping force error is greater than the error threshold, trigger an alarm.

2. The online monitoring method for brake disc end face runout according to claim 1, characterized in that: The clamping force error is subjected to fast Fourier decomposition to extract the main frequency and amplitude information of the harmonic component of the clamping force error.

3. The online monitoring method for brake disc end face runout according to claim 2, characterized in that: Collect multiple real-time wheel speeds N1, N2...NC in different time periods, and obtain the error frequencies T1, T2...TC at the moments corresponding to N1, N2...NC respectively; compare the corresponding N1 with T1, N2 with T2, NC with TC in turn, and determine whether they satisfy the multiple relationship, and whether the multiple multiple relationships are the same and are any positive integers.

4. An online monitoring device for brake disc end face runout, characterized in that: Includes mechanical brake system and control module system.

5. The online monitoring device for brake disc end face runout according to claim 4, characterized in that: The control module system includes a clamping force controller module, an end face runout calculation module, and an end face runout warning module; The clamping force controller module includes a force sensor for real-time feedback of the clamping force; The end face runout calculation module is used to judge the relationship between the error frequency and the wheel speed frequency to determine the magnitude of the clamping force jitter caused by the end face runout of the brake disc; The end face runout warning module is used to determine whether the end face runout exceeds a threshold value, and if so, issue a vehicle warning.

6. The online monitoring device for brake disc end face runout according to claim 4, characterized in that: The mechanical brake system comprises: a motor, a motor output shaft, a force sensor, a lead screw, a lead screw nut, a friction plate and a brake disc; The motor can provide rotational motion, drive the motor shaft and the lead screw to rotate, and then push the lead screw nut and the friction plate to move linearly, squeeze the brake disc, and generate braking force; the force sensor is fixed on the housing and contacts the lead screw stroke through the needle bearing, so as to be used for detecting the clamping force between the brake disc and the friction plate.

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