A motor protection method and system for an electronic mechanical brake system

Abstract

The present invention relates to the technical field of brake-by-wire control of electric vehicles, and specifically to a motor protection method and system for an electronic mechanical brake system. The solution of the present application determines the state of the motor by acquiring the state parameters of the motor. When it is determined that the motor is in a degraded state, the degraded state value of the degraded state is calculated according to the state parameters, and then the corresponding compensation coefficient is determined according to the degraded state value. The current limit value of the motor is corrected by the compensation coefficient, and finally, the target current limit value sent by the motor main controller is limited within the corrected current limit value to reduce the output current of the motor. By adopting the above-mentioned technical solution of the present application, overheating and demagnetization caused by excessive use of the motor can be effectively prevented, and the damage to the motor caused by special working conditions during operation can be reduced, thereby avoiding the failure of the service brake function.

Description

Technical Field

[0001] The present invention relates to the technical field of wire-controlled braking of electric vehicles, and in particular to a motor protection method and system for an electronic mechanical braking system. Background Art

[0002] Braking-by-wire systems are mainly divided into two categories: electronic hydraulic braking systems and electronic mechanical braking systems. Since electronic hydraulic braking systems retain most of the hydraulic components, the pipeline layout is complicated and they face problems such as brake fluid leakage. They are not truly brake-by-wire systems. The electronic mechanical braking system completely eliminates the hydraulic system and is an electronically controlled pure mechanical braking system. It has outstanding advantages such as compact structure, rapid response, precise control, and strong compatibility. It is considered to be the best solution for future automotive braking systems.

[0003] Currently, research on EMB (electromechanical brake system) is mostly focused on redundancy and improving control accuracy and speed. However, due to the limitation of its installation space, the motor has torque requirements, so its size cannot be too small, which makes it very difficult to have motor redundancy in the device. Therefore, improving the safety of the motor is a very important part of ensuring the safety of the EMB system.

[0004] In the prior art, the protection of EMB motors is mostly based on installing auxiliary systems or mechanical locking mechanisms to replace or assist the EMB system in completing the function of service braking when the motor is blocked. For example, the motor protection method, device, equipment and storage medium of an EMB system disclosed in patent number CN116279377A simply avoids the working conditions of EMB use, and still cannot provide effective protection for the brake motor for the full-scene use of EMB. On the one hand, EMB is prone to excessive use of the motor, causing damage; on the other hand, under special working conditions, it is easy to cause mechanical shock to the motor, and the method of reducing the current or stopping the motor under a single condition also has a great impact on the braking performance of the system. Summary of the invention

[0005] The present invention provides a motor protection method and system for an electronic mechanical brake system, which effectively solves the problem that the motor of the existing electronic mechanical brake system is easily damaged during operation, thereby causing the service brake function to fail.

[0006] According to a first aspect, an embodiment provides a motor protection method for an electronic mechanical brake system, comprising:

[0007] Acquire a state parameter of the motor, wherein the state parameter includes at least one of a current signal, a voltage signal, and a temperature signal;

[0008] Determine whether the motor is in a degraded state according to the state parameter, and if so, calculate a degraded state value of the degraded state according to the state parameter;

[0009] Determining a compensation coefficient of a current limit value preset in the degraded state according to the degraded state value;

[0010] Correcting the current limit value according to the compensation coefficient to obtain a corrected current limit value;

[0011] The target current value sent by the motor main controller is limited within the corrected current limit value to reduce the output current of the motor.

[0012] In an achievable implementation manner, judging whether the motor is in a degraded state according to the state parameter includes:

[0013] Determining the operating state of the motor according to the state parameter, the operating state of the motor including a normal state, a degraded state and a fault state;

[0014] The state parameter of the motor is compared with a preset degraded state range, and if the state parameter is within the degraded state range, it is determined that the motor is in a degraded state.

[0015] In an achievable implementation, the calculation formula for calculating the degraded state value of the degraded state is:

[0016]

[0017] Where S represents the degradation state value, V S is the real-time state parameter, T min is the minimum value of the degradation state range, T max This is the maximum value of the degraded state range.

[0018] In an achievable implementation, after determining that the running state of the motor is a degraded state, the method further includes:

[0019] Acquire a target current value sent by a motor main controller and an actual current value of the motor;

[0020] Determine whether the peak value of the target current value changes more than a preset number of times within a preset time, and whether the difference between the target current value and the actual current value at the same time is greater than a preset value;

[0021] If within a preset time, the peak value of the target current value changes more than a preset number of times, and at the same time, the difference between the target current value and the actual current value is greater than a preset value, the target current value of the motor is corrected to reduce the peak power operating condition of the motor.

[0022] In an achievable implementation manner, the correcting the target current value of the motor includes:

[0023] Performing low-pass filtering on the target current value to obtain a first target current value;

[0024] Calculating a maximum threshold interval and a minimum threshold interval of the first target current value according to a preset adjustment interval of the actual current value;

[0025] When the first target current value is within a minimum threshold interval of the first target current value, the first target current value is output as a final target current value;

[0026] When the first target current value is not within the minimum threshold interval of the first target current value, determining an upper threshold and a lower threshold of a maximum threshold interval of the first target current value;

[0027] The final target current value is calculated and outputted according to the current limit value of the current state of the motor, the first target current value, the upper threshold value and the lower threshold value.

[0028] In an achievable implementation manner, the calculating the maximum threshold interval and the minimum threshold interval of the first target current value according to the preset adjustment interval of the actual current value includes:

[0029] Setting the preset adjustment interval of the actual current value to 20% to 50% of the actual current value;

[0030] Determine that the upper threshold of the maximum threshold interval of the first target current value is the sum of the actual current value and 50% of the actual current value, and the lower threshold of the maximum threshold interval of the first target current value is the sum of the actual current value and -50% of the actual current value;

[0031] The upper threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and 20% of the actual current value, and the lower threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and -20% of the actual current value.

[0032] In an achievable implementation, the calculation formula for calculating the final target current value based on the current limit value of the current state of the motor, the first target current value, the upper threshold of the maximum threshold interval of the first target current value, and the lower threshold of the maximum threshold interval of the first target current value is:

[0033]

[0034] In the formula, S represents the final target current value, C taris the first target current value, CT max is the upper threshold of the maximum threshold interval, CT min is the lower threshold of the maximum threshold interval, C limt It is the current limit value of the motor in the current state.

[0035] According to a second aspect, an embodiment provides a motor protection system for an electronic mechanical brake system, comprising:

[0036] A first acquisition module, used to acquire a state parameter of the motor, wherein the state parameter includes at least one of a current signal, a voltage signal and a temperature signal;

[0037] A first judgment module, configured to judge whether the motor is in a degraded state according to the state parameter, and if so, calculate a degraded state value of the degraded state according to the state parameter;

[0038] A compensation coefficient calculation module, used to determine a compensation coefficient of a current limit value preset in the degraded state according to the degraded state value;

[0039] A first correction module, used for correcting the current limit value according to the compensation coefficient to obtain a corrected current limit value;

[0040] The control module is used to limit the target current value sent by the motor main controller within the corrected current limit value to reduce the output current of the motor.

[0041] In an achievable implementation, the motor protection system of the electronic mechanical braking system further includes:

[0042] A second acquisition module, used for the target current value sent by the motor main controller and the actual current value of the motor;

[0043] A second judgment module is used to judge whether the peak value of the target current value changes more than a preset number of times within a preset time, and whether the difference between the target current value and the actual current value at the same time is greater than a preset value;

[0044] and a second correction module;

[0045] If within a preset time, the peak value of the target current value changes more than a preset number of times, and at the same time, the difference between the target current value and the actual current value is greater than a preset value, the target current value of the motor is corrected by the second correction module to reduce the output power of the motor.

[0046] According to a third aspect, an embodiment provides a computer-readable storage medium, on which a program is stored, and the program can be executed by a processor to implement the method as described above.

[0047] According to the motor protection method and system of an electronic mechanical brake system of the above embodiment, the state of the motor is determined by obtaining the state parameters of the motor. When it is determined that the motor is in a degraded state, the degraded state value of the degraded state is calculated according to the state parameters, and then the corresponding compensation coefficient is determined according to the degraded state value. The current limit value of the motor is corrected by the compensation coefficient. Finally, the target current limit value sent by the motor main controller is limited within the corrected current limit value to reduce the output current of the motor. By adopting the above technical solution of the present application, overheating and demagnetization caused by excessive use of the motor can be effectively prevented, and the damage to the motor caused by special working conditions during operation can be reduced, thereby avoiding the failure of the service brake function. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The process of the motor protection method of the electronic mechanical brake system provided in this embodiment Figure 1 ;

[0049] Figure 2 A flow chart for determining whether a motor is in a degraded state provided in this embodiment;

[0050] Figure 3 The process of the motor protection method of the electronic mechanical brake system provided in this embodiment Figure 2 ;

[0051] Figure 4 A flow chart for correcting the target current value of the motor provided in this embodiment;

[0052] Figure 5 A corresponding curve relationship diagram of the degradation state value and the compensation coefficient provided in this embodiment;

[0053] Figure 6 The structural framework of the motor protection system of the electronic mechanical brake system provided in this embodiment Figure 1 ;

[0054] Figure 7 The structural framework of the motor protection system of the electronic mechanical brake system provided in this embodiment Figure 2 .

[0055] Figure numerals: 10, first acquisition module; 20, first judgment module; 30, compensation coefficient calculation module; 40, first correction module; 50, control module; 60, second acquisition module; 70, second judgment module; 80, second correction module. DETAILED DESCRIPTION

[0056] The present invention is further described in detail below by specific embodiments in conjunction with the accompanying drawings. Wherein similar elements in different embodiments adopt associated similar element numbers. In the following embodiments, many detailed descriptions are for making the present application better understood. However, those skilled in the art can easily recognize that some features can be omitted in different situations, or can be replaced by other elements, materials, methods. In some cases, some operations related to the present application are not shown or described in the specification, this is to avoid the core part of the present application being overwhelmed by too much description, and for those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations according to the description in the specification and the general technical knowledge in the art.

[0057] In addition, the features, operations or characteristics described in the specification can be combined in any appropriate manner to form various implementations. At the same time, the steps or actions in the method description can also be interchanged or adjusted in a manner that is obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for the purpose of clearly describing a certain embodiment and are not meant to be a required sequence, unless otherwise specified that a certain sequence must be followed.

[0058] The serial numbers of the components in this document, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings).

[0059] like Figure 1 As shown, the present embodiment provides a motor protection method for an electronic mechanical brake system, comprising the following steps:

[0060] Step 100: Acquire state parameters of a motor through a first acquisition module, where the state parameters include at least one of a current signal, a voltage signal, and a temperature signal.

[0061] In this step, the current signal MtrPhCur, voltage signal MtrPwrVolt and temperature signal MtrTemp of the motor are obtained respectively, wherein the voltage signal and current signal are both obtained from the bus, and the temperature signal is derived from the temperature sensor on the ECU circuit board.

[0062] Step 200: The first judgment module judges whether the motor is in a degraded state according to the state parameter. If so, step 300 is executed: the degraded state value of the degraded state is calculated according to the state parameter.

[0063] In this step, specifically, according to the actual impact of each signal value on the operation of the motor, the interval of each signal value is divided into a normal state, a degraded state, and a fault state. The normal state is a state in which the motor can be used normally; in the degraded state, the motor enters a protection state, which is used to start the degraded protection strategy for the internal control command, and the current needs to be limited before it can continue to work; and the fault state is a state in which the motor will lose its working ability after maintaining the maximum braking capacity for x seconds under external influences. After entering this state, the driver will be immediately warned, and the restriction algorithm will be released to allow the motor to maintain the maximum braking capacity within x seconds.

[0064] It should be noted that after adopting the motor protection scheme of the present application, the motor will not enter the fault state by itself, but will enter this state only when affected by the outside world. Because the motor protection degradation strategy of the present application will convert the influence of current, voltage and temperature on the motor into a degradation state value when the motor enters the degradation state, and the ratio of the degradation state value is a proportional signal of 0 to 100 to ensure the normal use of the motor.

[0065] Step 400: The compensation coefficient calculation module determines a compensation coefficient of a current limit value preset in a degraded state according to a degraded state value.

[0066] In this step, the control instructions sent by the motor controller are protected by determining that the motor enters a degraded state. The degraded protection strategy mainly limits the current, specifically setting three compensation coefficient intervals to degrade the motor application current value.

[0067] like Figure 5 As shown, the three intervals are: 0~A interval, point A is selected as the state value where the motor needs to enter the degradation protection (that is, the motor temperature reaches the value that needs protection), and the compensation coefficient of this interval is K1~K2; A~B interval, point B is selected as the state where the motor temperature continues to rise steadily to the limit value due to continuous braking (that is, the motor temperature does not drop after a period of time after reaching the value that needs protection, and the difference from point A is that the value is maintained or slightly increased for x ms), and the compensation coefficient of this interval is K2; B~C interval, point C is selected as the maximum temperature value that the motor can still withstand (that is, the maximum value of the motor working temperature), and the compensation coefficient of this interval is K2~0.

[0068] Step 500: The first correction module corrects the current limit value according to the compensation coefficient to obtain a corrected current limit value.

[0069] In this step, after determining the compensation coefficient of the current limit value preset in the degraded state according to the degraded state value, the motor operating current is degraded by multiplying the compensation coefficient by the set current limit, thereby achieving the effect of protecting the motor.

[0070] Step 600: Limit the target current value sent by the motor main controller to the corrected current limit value through the control module to reduce the output current of the motor.

[0071] Finally, after obtaining the corrected current limit value, the motor main controller outputs a target current value, which is less than or equal to the corrected current limit value, so as to achieve degradation processing of the motor working current.

[0072] In this embodiment, the motor is mainly protected against degradation through internal control. Specifically, during the operation of the motor, the motor's operating state is detected to determine whether the motor's operating parameters are in a degraded state. If so, the motor is protected against degradation to ensure that the motor's operating parameters are within a safe operating range, thereby avoiding motor failures caused by excessive use of the controller.

[0073] As a specific implementation method, it is determined whether the motor is in a degraded state according to the state parameters, such as Figure 2 As shown, the specific steps include:

[0074] Step 201: determining the running state of the motor according to the state parameter, where the running state of the motor includes a normal state, a degraded state and a fault state.

[0075] The following is an explanation using a specific example: the physical absolute value range of the current signal MtrPhCur is (0~120A), (0~70A) is set as the normal operating state current, (70~90A) is set as the degraded state operating current, and (90A~120A) is set as the fault state operating current; the physical value range of the voltage signal MtrPwrVolt is (6~18V), (10~14V) is set as the normal operating state voltage, (8~10V or 14~16V) is set as the degraded state operating voltage, and (6~8V or 16~18V) is set as the fault state operating voltage; the physical value range of the temperature signal MtrTemp is (-40~125℃), (-20~60℃) is set as the normal operating state temperature, (-40~-20 or 60~105℃) is set as the degraded state operating temperature, and (105~125℃) is set as the fault state operating temperature.

[0076] According to the acquired real-time state parameter (which can be a current signal, a voltage signal or a temperature signal), determine which of the above states the motor is in. When the acquired real-time state parameter is a current signal, it is compared with the above current value range; similarly, when the acquired real-time state parameter is a voltage signal, it is compared with the above voltage value range; when the acquired real-time state parameter is a temperature signal, it is compared with the above temperature value range.

[0077] Step 202: Compare the state parameter of the motor with a preset degraded state range. If the state parameter is within the degraded state range, determine that the motor is in a degraded state.

[0078] For example, if the current signal value of the motor at the current moment is 80A, and 80A is within the range of the degraded state (70 to 90A), it is determined that the motor is in the degraded state at this moment.

[0079] When it is determined that the system has entered a degraded state, it is necessary to calculate a degraded state value corresponding to the degraded state. Specifically, the calculation formula for calculating the degraded state value of the degraded state is:

[0080]

[0081] Where S represents the degradation state value, V S is the real-time state parameter, T min is the minimum value of the degradation state range, T max This is the maximum value of the degraded state range.

[0082] Taking the above current signal value of 80A as an example, according to the above formula, the calculated degradation state value is 50%. Then, according to Figure 5 The corresponding curve of the degraded state value and the compensation coefficient is shown, and the corresponding compensation coefficient is obtained. Assuming that the compensation coefficient corresponding to the degraded state value is 50% is k2, the compensation coefficient is multiplied by the current limit value of the degraded state (90A, calculated according to the maximum value of the degraded state range) to obtain the new current limit value of the degraded state (k2*90A). Finally, the new current limit value is output as the current limit value of the motor degraded state after the degraded protection. By judging the current state of the motor to determine the setting of the target current limit value, faults such as overheating and demagnetization caused by excessive use of the motor can be effectively prevented.

[0083] As a further improvement of this embodiment, after determining that the running state of the motor is a degraded state, Figure 3 As shown, the following steps are also included:

[0084] Step 700: Acquire the target current value sent by the motor main controller and the actual current value of the motor through the second acquisition module.

[0085] Specifically, when an external special working condition occurs, the motor will be impacted, resulting in a significant change in the state parameters of the motor output, thereby affecting the service life of the motor. Therefore, the method of this embodiment mainly uses a current suppression strategy to ensure that the output current of the motor is still within a safe range when the motor is impacted and damaged by an external special working condition.

[0086] Taking the change of ABS working condition as an example, ABS needs to release the brakes continuously for many times in a short period of time, in which case the motor is very susceptible to impact. It is too complicated for the EMB (Electronic Mechanical Braking) execution end to judge the braking working condition of the system by external conditions. This embodiment reduces the impact torque of the motor by suppressing the output current of the motor, thereby reducing the impact damage to the motor.

[0087] Step 800: Determine, by a second determination module, whether the peak value change of the target current value exceeds a preset number of times within a preset time, and whether the difference between the target current value and the actual current value at the same time is greater than a preset value.

[0088] First, it is determined whether the motor is in a degraded state and not in a motor fault state according to the state parameter information of the motor, because the current suppression algorithm can only be performed when it is not in a fault state. Then, the braking command information is obtained, wherein the braking command information includes the motor control command information MtrTarCur and the motor real-time torque information MtrFbkCur. The motor control command information is specifically the target current value, and the motor real-time torque information is specifically the actual current value. It is determined whether the motor is affected by external special working conditions according to the target current value and the actual current value.

[0089] In this embodiment, the current suppression strategy of the present application scheme is adopted to target different operating conditions. No matter what special operating conditions are used, damage to the motor will be caused by impacting the motor. Therefore, the input conditions for judging the special operating conditions are the current current value of the motor (equivalent to the torque value) and the changes in the control instructions of the controller.

[0090] Specifically, the difference between the motor target current value and the motor actual current value is determined. If the difference between the target current value and the actual current value is greater than 50% of the target current value, and the differential sign of the target current value changes more than y times (in this embodiment, y can be set to 3) within x ms (in this embodiment, x can be set to 150 ms), it is determined that the brake motor protection working condition is entered. It should be noted that the differential sign change of the target current value can be understood as: within a certain period of time, the target current value changes from a positive value to a negative value, or the target current value changes from a negative value to a positive value.

[0091] If the peak value of the target current value changes more than a preset number of times within the preset time, and the difference between the target current value and the actual current value at the same time is greater than the preset value, execute step 900: correct the target current value of the motor through the second correction module to reduce the peak power operating condition of the motor.

[0092] If it is determined that the above two requirements are met at the same time (i.e. the difference between the target current value and the actual current value is greater than 50% of the target current value, and the differential sign of the target current value changes more than three times within x ms), then the current suppression strategy is executed to reduce the torque impacted on the motor.

[0093] In this embodiment, the target current value of the motor is corrected, such as Figure 4 As shown, the specific steps include:

[0094] Step 910: low-pass filter the target current value to obtain a first target current value. In this step, the target current value can be understood as a target current signal. First, the target current signal needs to be low-pass filtered to filter out the high-frequency vibration caused by external noise to obtain a first target current value in the low-frequency band.

[0095] Step 920: Calculate the maximum threshold interval and the minimum threshold interval of the first target current value according to the preset adjustment interval of the actual current value.

[0096] Then, the actual current value of the motor before the motor enters the working condition is used as the basis for setting the maximum threshold interval and the minimum threshold interval. Specifically, the preset adjustment interval of the actual current value can be set to 20% to 50% of the actual current value; then, the upper threshold of the maximum threshold interval of the first target current value is determined to be the sum of the actual current value and 50% of the actual current value, and the lower threshold of the maximum threshold interval of the first target current value is determined to be the sum of the actual current value and -50% of the actual current value; the upper threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and 20% of the actual current value, and the lower threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and -20% of the actual current value.

[0097] That is, 20% of the actual current value floating up and down based on the actual current value can be used as the minimum threshold interval of the preset adjustment interval (i.e., the minimum threshold interval of the first target current value); 50% of the actual current value floating up and down based on the actual current value can be used as the maximum threshold interval of the preset adjustment interval (i.e., the maximum threshold interval of the first target current value).

[0098] For example, if the real-time current is 40A, the adjustment range is 8 to 20A, then the minimum threshold range of the first target current value is (40-8)A to (40+8)A, that is, 32 to 48A; the maximum threshold range of the first target current value is (40-20)A to (40+20)A, that is, 20 to 60A.

[0099] Step 930: When the first target current value is within the minimum threshold interval of the first target current value, the first target current value is output as the final target current value.

[0100] When the first target current value at the same moment does not exceed the upper and lower floating range of 20% of the actual current value at this moment, there is no need to adjust the first target value. That is, when the first target current value is in the range of 32 to 48A, the first target current value is output as the final target current value. During the operation of the motor, the output target current value is adjusted according to the actual current value of the motor at the current moment, so that the target current value and the real current value (actual current value) at the next moment are in a stable state, avoiding the impact caused by excessive changes in the motor current, thereby protecting the motor.

[0101] For example, if the first target current value at the same time is 45 A, which is within the range of 32 to 48 A, 45 A is output as the final target current value.

[0102] Step 940: When the first target current value is not within the minimum threshold interval of the first target current value, determining the upper threshold and the lower threshold of the maximum threshold interval of the first target current value.

[0103] When the first target current value at the same moment is not within (exceeds) the floating range of 20% of the actual current value at this time, the first target current value needs to be adjusted. The adjustment method is to proportionally reduce the motor command growth within the range of 20% to 50%, that is, to proportionally reduce the difference between the first target current value and the actual current value to the value of 20% to 50% of the actual current value, thereby suppressing the change of current and thus suppressing the impact of external working conditions on the motor. Specifically, it is necessary to first determine the adjustment range, expand the adjustment range of the first target current value to the range of the maximum threshold interval, then it is necessary to determine the upper and lower thresholds of the maximum threshold interval.

[0104] For example, when the first target current value at the same time is not within the range of 32 to 48 A, the first target current value needs to be adjusted so that the adjusted first target current value is within the range of 20 to 60 A. The specific method for adjusting the first target current value is shown in the following steps.

[0105] Step 950: Calculate and output the final target current value according to the current limit value of the current state of the motor, the first target current value, the upper threshold value and the lower threshold value.

[0106] Specifically, the final target current value is calculated according to the current limit value of the current state of the motor, the first target current value, the upper threshold of the maximum threshold interval of the first target current value, and the lower threshold of the maximum threshold interval of the first target current value, and the calculation formula is as follows:

[0107]

[0108] In the formula, S represents the final target current value, C tar is the first target current value, CT max is the upper threshold of the maximum threshold interval, CT min is the lower threshold of the maximum threshold interval, C limt It is the current limit value of the motor in the current state.

[0109] Continuing to refer to the above example, the maximum current limit value of the current degradation state range is 90A for calculation. If the target current at the same time is 60A, the upper threshold of the maximum threshold interval is 60A, and the lower threshold of the maximum threshold interval is 20A, then according to the above formula, the final target current value calculated is approximately 46.67A, and 46.67A is output as the final target current value.

[0110] like Figure 6 As shown, the motor protection system of an electronic mechanical brake system provided in this embodiment includes a first acquisition module 10, a first judgment module 20, a compensation coefficient calculation module 30, a first correction module 40 and a control module 50. Among them, the first acquisition module 10 is used to obtain the state parameters of the motor, and the state parameters include at least one of a current signal, a voltage signal and a temperature signal; the first judgment module 20 is used to judge whether the motor is in a degraded state according to the state parameters, and if so, calculate the degraded state value of the degraded state according to the state parameters; the compensation coefficient calculation module 30 is used to determine the compensation coefficient of the current limit value preset in the degraded state according to the degraded state value; the first correction module 40 is used to correct the current limit value according to the compensation coefficient to obtain the corrected current limit value; the control module 50 is used to limit the target current value sent by the motor main controller to the corrected current limit value to reduce the output current of the motor.

[0111] The motor protection system of the electronic mechanical brake system of the present embodiment specifically includes a first acquisition module 10, a first judgment module 20, a compensation coefficient calculation module 30, a first correction module 40 and a control module 50, wherein the functions and effects of each module have been described in detail in the above method embodiment, and will not be elaborated in detail in the present embodiment.

[0112] As a further improvement of this embodiment, Figure 7As shown, the motor protection system of the electronic mechanical brake system also includes a second acquisition module 60, a second judgment module 70 and a second correction module 80. Among them, the second acquisition module 60 is used for the target current value sent by the motor main controller and the actual current value of the motor; the second judgment module 70 is used to judge whether the peak value change of the target current value exceeds the preset number of times within the preset time, and whether the difference between the target current value and the actual current value at the same time is greater than the preset value. If the peak value change of the target current value exceeds the preset number of times within the preset time, and the difference between the target current value and the actual current value at the same time is greater than the preset value, the target current value of the motor is corrected by the second correction module 80 to reduce the output power of the motor.

[0113] The motor protection system of the electronic mechanical brake system of this embodiment specifically further includes a second acquisition module 60, a second judgment module 70 and a second correction module 80. The functions and effects of each module have been described in detail in the above method embodiment, and will not be described in detail in this embodiment.

[0114] This embodiment provides a computer-readable storage medium, on which a program is stored, and the program can be executed by a processor to implement the above method. Since the motor protection method of the electronic mechanical brake system has been described in detail in the above embodiment, this embodiment will not be described in detail here.

[0115] Those skilled in the art will appreciate that all or part of the functions of the various methods in the above-mentioned embodiments can be implemented by hardware or by computer programs. When all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can be stored in a computer-readable storage medium, and the storage medium can include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to implement the above-mentioned functions. For example, the program is stored in the memory of the device, and when the program in the memory is executed by the processor, all or part of the above-mentioned functions can be implemented. In addition, when all or part of the functions in the above-mentioned embodiments are implemented by computer programs, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash disk or mobile hard disk, and can be downloaded or copied and saved in the memory of the local device, or the system of the local device is updated, and when the program in the memory is executed by the processor, all or part of the functions in the above-mentioned embodiments can be implemented.

[0116] The above specific examples are used to illustrate the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art, according to the concept of the present invention, some simple deductions, modifications or substitutions can be made.

Claims

1. A motor protection method for an electronic mechanical brake system, characterized in that: include: Acquire a state parameter of the motor, wherein the state parameter includes at least one of a current signal, a voltage signal, and a temperature signal; It is determined whether the motor is in a degraded state according to the state parameter. If so, the degraded state value of the degraded state is calculated according to the state parameter; the degraded state value is used to characterize the influence of current, voltage and temperature on the motor, and the degraded state value is a proportional signal of 0 to 100; the calculation formula for calculating the degraded state value of the degraded state is: Where S represents the degradation state value, V S is the real-time state parameter, T min is the minimum value of the degradation state range, T max It is the maximum value of the degradation status range; Determining a compensation coefficient of a current limit value preset in the degraded state according to the degraded state value; Correcting the current limit value according to the compensation coefficient to obtain a corrected current limit value; The target current value sent by the motor main controller is limited within the corrected current limit value to reduce the output current of the motor.

2. The motor protection method of the electronic mechanical brake system according to claim 1, characterized in that: The step of determining whether the motor is in a degraded state according to the state parameter comprises: Determining the operating state of the motor according to the state parameter, the operating state of the motor including a normal state, a degraded state and a fault state; The state parameter of the motor is compared with a preset degraded state range, and if the state parameter is within the degraded state range, it is determined that the motor is in a degraded state.

3. The motor protection method of the electronic mechanical brake system according to claim 1, characterized in that: After determining that the running state of the motor is a degraded state, the method further includes: Acquire a target current value sent by a motor main controller and an actual current value of the motor; Determine whether the peak value of the target current value changes more than a preset number of times within a preset time, and whether the difference between the target current value and the actual current value at the same time is greater than a preset value; If within a preset time, the peak value of the target current value changes more than a preset number of times, and at the same time, the difference between the target current value and the actual current value is greater than a preset value, the target current value of the motor is corrected to reduce the peak power operating condition of the motor.

4. The motor protection method of the electronic mechanical brake system according to claim 3, characterized in that: The correcting the target current value of the motor includes: Performing low-pass filtering on the target current value to obtain a first target current value; Calculating a maximum threshold interval and a minimum threshold interval of the first target current value according to a preset adjustment interval of the actual current value; When the first target current value is within a minimum threshold interval of the first target current value, the first target current value is output as a final target current value; When the first target current value is not within the minimum threshold interval of the first target current value, determining an upper threshold and a lower threshold of a maximum threshold interval of the first target current value; The final target current value is calculated and outputted according to the current limit value of the current state of the motor, the first target current value, the upper threshold value and the lower threshold value.

5. The motor protection method of the electronic mechanical brake system according to claim 4, characterized in that: The calculating the maximum threshold interval and the minimum threshold interval of the first target current value according to the preset adjustment interval of the actual current value includes: Setting the preset adjustment interval of the actual current value to 20% to 50% of the actual current value; Determine that the upper threshold of the maximum threshold interval of the first target current value is the sum of the actual current value and 50% of the actual current value, and the lower threshold of the maximum threshold interval of the first target current value is the sum of the actual current value and -50% of the actual current value; The upper threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and 20% of the actual current value, and the lower threshold of the minimum threshold interval of the first target current value is determined to be the sum of the actual current value and -20% of the actual current value.

6. The motor protection method of the electronic mechanical brake system according to claim 4, characterized in that: The calculation formula for calculating the final target current value according to the current limit value of the current state of the motor, the first target current value, the upper threshold of the maximum threshold interval of the first target current value, and the lower threshold of the maximum threshold interval of the first target current value is: In the formula, S represents the final target current value, C tar is the first target current value, CT max is the upper threshold of the maximum threshold interval, CT min is the lower threshold of the maximum threshold interval, C limt It is the current limit value of the motor in the current state.

7. A motor protection system for an electronic mechanical brake system, characterized in that: include: A first acquisition module, used to acquire a state parameter of the motor, wherein the state parameter includes at least one of a current signal, a voltage signal and a temperature signal; The first judgment module is used to judge whether the motor is in a degraded state according to the state parameters, and if so, calculate the degraded state value of the degraded state according to the state parameters; the degraded state value is used to characterize the influence of current, voltage and temperature on the motor, and the degraded state value is a proportional signal of 0 to 100; the calculation formula for calculating the degraded state value of the degraded state is: Where S represents the degradation state value, V S is the real-time state parameter, T min is the minimum value of the degradation state range, T max It is the maximum value of the degradation status range; A compensation coefficient calculation module, used to determine a compensation coefficient of a current limit value preset in the degraded state according to the degraded state value; A first correction module, used for correcting the current limit value according to the compensation coefficient to obtain a corrected current limit value; The control module is used to limit the target current value sent by the motor main controller within the corrected current limit value to reduce the output current of the motor.

8. The motor protection system of the electronic mechanical brake system according to claim 7, characterized in that: Also includes: A second acquisition module, used for the target current value sent by the motor main controller and the actual current value of the motor; A second judgment module is used to judge whether the peak value of the target current value changes more than a preset number of times within a preset time, and whether the difference between the target current value and the actual current value at the same time is greater than a preset value; and a second correction module; If within a preset time, the peak value of the target current value changes more than a preset number of times, and at the same time, the difference between the target current value and the actual current value is greater than a preset value, the target current value of the motor is corrected by the second correction module to reduce the output power of the motor.

9. A computer-readable storage medium, characterized in that: The medium stores a program, which can be executed by a processor to implement the method according to any one of claims 1 to 6.

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