Method and system for torque monitoring of electric vehicles

Abstract

Method for torque monitoring of the electric vehicle, characterized in that the method comprises the following steps: - a vehicle operation signal and a vehicle state signal are detected, and an actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle state signal; - it is judged whether a fault exists in the control system for the entire vehicle, and a fault regulating torque is generated according to the type of fault if the fault exists; - if the control system for the whole vehicle is OK, an actual output torque of the electric motor is used as a requested torque, otherwise the said fault regulation torque is used as the requested torque; - a torque limit is calculated based on the vehicle operating signal, the vehicle status signal and the capability of the components by calculating a maximum and a minimum value of the current deliverable torque based on the vehicle operating signal, the vehicle status signal and the capability of the components, and calculating a corresponding gradient based on the change in the torque and determining a gradient limit; - a comparison of the requested torque with the stated torque limit is carried out, and the requested torque is limited within the range of the torque limit, and an output torque is obtained by comparing the maximum and minimum values ​​of the deliverable torque with the stated requested torque; if the requested torque is within this range, the requested torque is delivered, otherwise the maximum value is delivered if the requested torque is greater than the stated maximum value; and the minimum value is delivered if the requested torque is less than the minimum value; and when the requested torque is varied, it is raised or lowered evenly and smoothly according to the size of the gradient limit.

Description

Technical area

[0001] The present invention relates to the technical field of electric vehicle control, in particular to a method and a system for torque monitoring of the electric vehicle. State of the art

[0002] In the 20th century, rapid economic development relies mainly on petrochemical energy sources, mainly oil, coal, and natural gas. However, with the passage of time, the supply of petrochemical energy sources has gradually decreased. At the same time, the exhaust gases generated by the consumption of petrochemical energy sources have brought more and more problems to humanity, such as abnormal phenomena such as the greenhouse effect, fog and haze, etc. Under the pressure of environmental pollution and the energy source crisis, it is necessary to develop new electric vehicles.The pure electric vehicle is the only zero-discharge vehicle in which the internal combustion engine is replaced by an electric motor, the noise is low, it does not cause environmental pollution, the widely generated electric energy is used as the driving force, and the vehicle battery can be charged with cheap electricity from the power grid during the off-peak power consumption period, such as at night, so as to compensate for the difference between peak power consumption and off-peak power consumption, and the utilization rate of the energy source is effectively improved.

[0003] The electric vehicle includes an entire vehicle control device, an electric motor, an electric motor control device, a battery management system, a driving power battery cell group, a charging device, a display terminal, etc. The electric motor is the sole driving power source of the electric vehicle; the entire vehicle control device is the core element of the entire vehicle control system, controlling the seamless connection of the electric motor control device and the transmission system to achieve better driving performance and energy optimization.

[0004] The electric vehicle is powered by an electric motor, which has a completely different torque characteristic than an internal combustion engine. In certain cases, the vehicle's torque control may be caused by hardware problems, software problems, electromagnetic interference, artificial faults, etc. Such a case poses a very serious hidden threat to the vehicle's safety.

[0005] The torque of an electric vehicle plays a very important role in the safety of the entire vehicle, so it is necessary to monitor the torque of the electric vehicle. Regarding the well-known torque monitoring method, the following solutions are available: 1. A single torque monitoring control unit is specifically designed to monitor the torque requested by the entire vehicle control system and the actual torque delivered by the electric motor. Implementing this solution requires the addition of an additional control system, resulting in increased costs and a relatively complex system. 2. The actual operating parameters of the electric motor are monitored by the electric motor control unit. Based on the actual operating parameters, the electric motor torque is estimated, and then the estimated torque is compared with the required torque. If the difference is within the reasonable range, this indicates that the electric motor torque is OK. Since the electric motor torque is estimated based on the electric motor's operating parameters, the accuracy is not high. Furthermore, with this solution, only the electric motor torque is monitored, and the required torque of the control unit for the entire vehicle is not monitored. 3. When monitoring the command torque from the entire vehicle control device, a monitoring system is built into the entire vehicle control device, so that the command torque of the electric motor can be monitored from the source, and sudden changes will not occur. However, the internal memory capacity of the entire vehicle control device is limited, and the operating frequency is determined. When the monitoring system is added to the entire vehicle control device, the number of programs of the entire vehicle control device increases significantly, the running time is extended, and the response speed is slowed, thus affecting the safety of the entire vehicle.

[0006] From the invention patent application CN103625306 (publication) entitled "System for torque monitoring of the electric vehicle" by the same applicant, a method for torque monitoring is known, wherein a torque monitoring system is built into the control device for the entire vehicle, thereby eliminating the need to add a separate control device, and in addition, the resources for internal storage are saved, so that the control device for the vehicle can react quickly.However, with the technical solution known from the above-mentioned document, it is impossible to perform limit processing of the output of the requested torque; in practical driving, the control of the torque of the electric motor by the control device may lead to a sudden change to a larger or smaller value that is outside the rational range, which simultaneously leads to a greater acceleration or a greater deceleration of the vehicle at the moment, and the driving is unsatisfactorily safe and smooth.

[0007] DE 10 2008 046 240 B4 discloses that a motor torque monitoring device (MTM) is provided to monitor the torque generated by the electric motor. The MTM can be integrated into control architectures for multi-layer or multi-level vehicle systems. Furthermore, the MTM can assume the functionality of torque control functions, including, but not necessarily limited to, current control, pulse width modulation (PWM), temperature compensation, torque limiting, torque protection, or the like. The torque generated by the electric motor is monitored to provide a warning or transmit fault information if the motor torque integrity is not within desired operating criteria. Appropriate countermeasures can be taken in response to the warning or upon receipt of the fault information.It is provided that the processor determines the achieved motor torque based on a rotor position of the electric motor and a phase current of the electric motor when the motor speed is not greater than a first predetermined threshold, determines the achieved motor torque based on a loss-compensated power supplied to the electric motor when the motor speed is greater than the first predetermined threshold, compares the achieved motor torque with the torque command, and indicates a fault if the achieved motor torque is not within a predetermined tolerance of the torque command.

[0008] DE 10 2012 200 608 A1 describes that for torque monitoring, an actual torque acting on the drive train is compared with a specified torque, whereby the actual torque is recorded by means of the torque sensor or taken from a control unit of an electric motor, without complex modeling from the various variables. Content of the invention

[0009] The present invention is characterized by the method according to claim 1 and by the system according to claim 5.

[0010] The present invention is based on the object of eliminating the technical problem of vehicle shutdown potentially caused by a malfunction of the control device for the entire vehicle. The present invention provides a method for torque monitoring, wherein the torque output by the control device for the entire vehicle is monitored and regulated in real time.

[0011] In order to solve the above-mentioned technical problem, the following technical solution is provided in the present invention: A procedure for torque monitoring of the electric vehicle includes the following steps: - a vehicle operation signal and a vehicle state signal are detected, and an actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle state signal; - it is judged whether there is a fault in the control system for the entire vehicle, a fault regulating torque is generated according to the type of fault if the fault exists; - if the control system for the whole vehicle is OK, an actual output torque of the electric motor is used as a requested torque, otherwise the said fault regulation torque is used as the requested torque; - a torque limit is calculated based on the vehicle operating signal, the vehicle status signal and the capability of the components; - a comparison of the requested torque with the specified torque limit is carried out, and the requested torque is limited within the range of the torque limit so that an output torque is obtained.

[0012] Preferably, the step for calculating the actual torque of the electric motor includes: - a first torque is obtained by analyzing a torque, then a second torque is obtained by filtering, and a third torque is obtained by deciding a torque, finally the actual output torque is obtained by the torque output.

[0013] Preferably, it is judged whether there is a fault in the control system for the entire vehicle, if the fault exists, the fault regulating torque is generated according to the type of fault, the step of which includes: - a first optimized torque is obtained by the optimized analysis of a torque, a second optimized torque is obtained by the optimized filtering of the first torque, a third optimized torque is obtained by the optimized decision on the second torque; - a comparison of the first torque with the first optimization torque, a comparison of the second torque with the second optimization torque, a comparison of the third torque with the third optimization torque and a comparison of the third torque with the actual output torque are performed separately, and their difference value is obtained; - if the difference value is smaller than the set threshold, it is judged that the actual torque is OK; if the difference value is larger than the set threshold, it is judged that there is a system fault, and according to the torque with the existing difference value, the type of fault is judged; - the torque is regulated according to the type of disturbance and a disturbance regulation torque is generated.

[0014] Preferably, the optimized analysis of a torque is carried out as the simplified analysis of a torque, the optimized filtering of a torque is carried out as the simplified filtering of a torque, and the optimized decision about a torque is carried out as the simplified decision about a torque.

[0015] Preferably, the torque limit is calculated based on the vehicle operating signal, the vehicle condition signal and the capability of the components, the step includes: - based on the vehicle operating signal, the vehicle status signal and the capability of the components, a maximum and a minimum value of the current deliverable torque are calculated; - after changing the torque, a gradient is calculated and a gradient limit value is obtained.

[0016] Preferably, a comparison of the requested torque with the torque limit is carried out, the requested torque is limited in the range of the torque limit, and the output torque is obtained, the step for this comprises: - a comparison is made between the maximum and minimum values ​​of the current deliverable torque and the value of the requested torque; if the requested torque is within this range, the requested torque is delivered; otherwise, the maximum value is delivered if the requested torque is greater than the maximum value; and the minimum value is delivered if the requested torque is less than the minimum value; - when the requested torque is changed, it is raised or lowered smoothly and evenly according to the size of the gradient limit.

[0017] An electric vehicle torque monitoring system includes: - an actual torque calculation unit: a vehicle operation signal and a vehicle state signal are detected, and the actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle state signal; - a calculation unit for the disturbance control torque: it is judged whether a disturbance exists; if a disturbance exists, the disturbance control torque is generated according to the type of disturbance; - a requested torque output unit: if the system is OK, the actual output torque of the electric motor is used as the requested torque, otherwise the fault regulation torque is used as the requested torque; - a calculation unit for the limit value: the torque limit value is calculated according to the vehicle operating signal, the vehicle status signal and the capability of the components; - a limit value output unit: a comparison of the requested torque with the specified torque limit is carried out, and the requested torque is limited within the range of the torque limit, and the output torque is thereby obtained.

[0018] Preferably, the calculation unit for the actual torque includes: - a torque analysis module: the first torque is obtained by analyzing the current torque; - a torque filtering module: the second torque is obtained by filtering; - a torque arbitration module: the third torque is obtained by deciding on a torque; - a torque output module: the actual output torque is obtained by the torque output.

[0019] Preferably, the calculation unit for the disturbance regulation torque comprises: - a torque generation optimization module comprising: - a torque analysis optimization sub-module in which a first optimized torque is obtained by the optimized analysis of a torque; - a torque filtering optimization sub-module in which a second optimized torque is obtained by the optimized filtering of a torque; - a torque arbitration optimization sub-module in which the third optimized torque is obtained by the optimized decision on a torque; - an assessment module comprising: - a first assessment sub-module in which a comparison of said first torque with said first optimized torque is carried out; - a second assessment sub-module in which a comparison of said second torque with said second optimized torque is carried out; - a third assessment sub-module in which a comparison of said third torque with said third optimized torque is carried out; - a fourth assessment sub-module in which a comparison of the actual output torque with the third torque is carried out; - a fault diagnosis module for judging that the actual torque is normal when said difference value is less than the set threshold; for judging that there is a fault in the control system for the entire vehicle when said difference value is greater than the set threshold, and for judging the type of fault according to the torque with the existing difference value; - a system protection module in which the torque is regulated according to the type of fault and a fault regulation torque is generated.

[0020] Preferably, the torque analysis optimization submodule is implemented as the simplified torque analysis module, the torque filtering optimization submodule is implemented as the simplified torque filtering module, and the torque arbitration optimization submodule is implemented as the simplified torque arbitration module.

[0021] Preferably, the unit of account for the limit value includes: - a torque limit calculation module in which a maximum and a minimum value of the current deliverable torque are calculated according to the vehicle operating signal, the vehicle status signal and the capability of the components; - a torque change limit module in which a gradient is calculated according to the torque change and a gradient limit is determined.

[0022] Preferably, the said delivery unit for the limit value comprises: - an upper and lower limit processing module, in which a comparison is made between the maximum and minimum values ​​of the current deliverable torque and the value of the requested torque; the requested torque is delivered if the requested torque is within this range, otherwise the said maximum value is delivered if the requested torque is greater than the said maximum value, and the said minimum value is delivered if the requested torque is less than the said minimum value; - a processing module for the change limit value, in which it is raised or lowered evenly and smoothly according to the size of the slope limit value when the value of the requested torque is changed.

[0023] Compared with the prior art, the above-mentioned technical solution according to the present invention has the following advantages: 1. In the electric vehicle torque monitoring method of the present invention, the commanded torque is not directly used as the output torque of the entire vehicle control device. Instead, a torque limit value is determined based on the vehicle operation signal, the vehicle condition signal, and the component capability, and the output torque is limited within the torque limit value range. This protects the entire vehicle control output from sudden changes or prevents the torque value from exceeding the safe range, ensuring safe and smooth driving. 2. In the method and system for torque monitoring of the electric motor, the correct torque of the electric motor monitoring is obtained by the actual torque calculation unit according to the vehicle operation signal and the vehicle condition signal, and a comparison of the torque of the electric motor monitoring with the actual torque obtained by the control device for the entire vehicle according to the vehicle operation signal and the vehicle condition signal is carried out, so that it can be judged whether the actual torque obtained by the control device for the entire vehicle is within the rational range. Therefore, the erroneous torque caused by causes such as hardware problems, software problems of the control device for the entire vehicle, electromagnetic interference, and artificial errors and obtained by the control device of the vehicle through calculation can be effectively detected and monitored.This protects the torque output by the entire vehicle control system from the occurrence of irrational conditions caused by problems occurring in the entire vehicle control system, and protects the vehicle's torque from being cut off. At the same time, the entire vehicle control system will respond quickly to the driver's intentions by optimizing torque monitoring. Ultimately, the goal of ensuring safe driving is achieved. Furthermore, this monitoring system is effective and simple for monitoring and controlling the electric motor torque of the entire vehicle control system in various ways. 3. In the electric vehicle torque monitoring method according to the present invention, an optimization torque monitoring system is incorporated into the entire vehicle control device. It eliminates the need to add a separate control device, and greatly saves internal memory resources, thus ensuring a relatively fast response speed of the entire vehicle control device. Furthermore, RAM data errors caused by a problem with any byte stored in the chip or calibration errors are avoided. This further improves torque monitoring, ensures the rationalization of the electric motor's required torque, and better ensures driving safety. Short description of the drawings

[0024] In the following, the present invention will be explained in detail using some concrete embodiments in conjunction with the drawings in order to facilitate the understanding of the present invention, wherein Fig. 1 Flowchart of the method according to the first embodiment of the present invention; Fig. 2 Block diagram of the structure of the system according to the second embodiment of the present invention. Embodiment

[0025] In order for the person skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is explained in detail below using some embodiments in conjunction with the drawings. Example 1:

[0026] In the present embodiment, a method for monitoring the torque of the electric motor is specified, comprising the following steps:First, a vehicle operation signal and a vehicle state signal are detected by the control device for the entire vehicle, and based on the vehicle operation signal and the vehicle state signal, the actual torque of the electric motor is calculated. According to the driver's request during driving, the vehicle operation signal is determined, which includes a braking signal, an acceleration signal, and a gear signal; and the vehicle state signal is determined according to the real-time driving state. The driving state signal includes a driving speed, a rotational speed of the electric motor, the maximum traction torque, and the maximum power generation torque of the electric motor. The maximum traction torque and the maximum power generation torque of the electric motor are calculated by the control device for the entire vehicle according to the charge state of the battery of the electric vehicle, the temperature of the battery, the temperature of the electric motor,The temperature of the electric motor control unit and the performance of the fittings are calculated. Based on the difference between the actual torque and the electric motor monitoring torque calculated above, it is judged whether a fault exists in the entire vehicle control system. If a fault exists, the fault-regulating torque is generated according to the type of fault. The electric motor monitoring torque is the correct torque obtained by the torque generation optimization module based on the vehicle operation signal and the vehicle status signal. If the entire vehicle control system is OK, the actual torque output by the electric motor is used as the requested torque; otherwise, the fault-regulating torque is used as the requested torque. Meanwhile, a torque limit is set based on the vehicle operation signal.The vehicle condition signal and the component capability are calculated. Finally, the requested torque is compared with the torque limit, the requested torque is limited within the torque limit range, and the output torque is obtained.

[0027] In the torque monitoring system, a correct torque of the electric motor monitor is determined according to the vehicle operation signal and the vehicle state signal by the torque generation optimization module, and a comparison is made of the torque of the electric motor monitor with the actual torque obtained by the control device for the entire vehicle according to the vehicle operation signal and the vehicle state signal, and it is judged according to the difference value between the two whether the actual electric motor torque obtained by the control device for the entire vehicle is within the rational range, therefore, the torque caused by the causes such as the hardware problem, the software problem of the control device for the entire vehicle,The potentially faulty torque of the electric motor caused by electromagnetic interference and artificial faults, and calculated by the vehicle control system, can be effectively detected and monitored, thus protecting the torque output by the vehicle-wide control system from the occurrence of an irrational condition, and the vehicle's torque is protected from being cut off. This fulfills the driver's wishes while effectively ensuring driving safety. Furthermore, by optimizing the monitoring torque detection modules, the monitoring torque can be quickly obtained by the vehicle-wide control system, and the response time to the fault in the vehicle-wide control system is reduced, thus ensuring driving safety.

[0028] In the present embodiment, a torque limit value is calculated according to the vehicle operation signal, the vehicle condition signal and the capability of the components, and the output torque is limited in the range of the torque limit value, so that the torque output from the control device for the entire vehicle is protected from sudden change or is protected from exceeding the safe range of the torque value, and the safe and smooth driving is thereby ensured.

[0029] In the present embodiment, the actual torque includes a first torque, a second torque, and a third torque; the monitoring torque includes a first optimization torque, a second optimization torque, and a third optimization torque.

[0030] In the torque monitoring method according to the present embodiment, the calculation of the individual torques from the actual torque comprises the following steps: The first torque is obtained by analyzing the vehicle operation signal and the vehicle state signal, the smooth second torque is obtained by filtering the first torque, the third torque is obtained by calculating the second torque according to the maximum traction torque of the electric motor and the maximum power generation torque of the electric motor, and an actual output torque is obtained by outputting the third torque.

[0031] In the electric motor torque monitoring method, the steps for judging whether there is a fault in the control system for the entire vehicle and for judging the type of fault are as follows: First, the correct monitoring torque of the electric motor is obtained based on the vehicle operating signal and the vehicle status signal. The algorithm for calculating the torque of the electric motor monitoring is obtained by simplifying the algorithm based on the above-mentioned algorithm for calculating the actual torque of the electric motor. The goal of this simplification is to reduce the load on the control system for the entire vehicle and reduce the response time to the disturbance. The monitoring torque of the electric motor includes a first optimization torque, a second optimization torque, and a third optimization torque.And the first optimization torque is obtained by the optimized analysis of a torque of the vehicle operation signal and the vehicle state signal, then the second optimization torque is obtained by the optimized filtering of the first torque, finally the third optimization torque is obtained by the optimized decision on the second torque.

[0032] In addition, the comparison of the first torque with the first optimization torque, the comparison of the second torque with the second optimization torque, the comparison of the third torque with the third optimization torque, and the comparison of the third torque with the actual output torque are performed, and their difference value is obtained.

[0033] Then, the relationship between the above-mentioned difference value and the set threshold value is judged; if the difference value is smaller than the set threshold value, it is judged that the actual torque is OK; if the difference value is larger than the set threshold value, it is judged that there is a disturbance in the torque output of the control device for the entire vehicle, and the type of disturbance is judged according to the torque with the existing difference value that is larger than the set threshold value; if the difference value between the first torque and the first optimization torque has exceeded the set threshold value, the disturbance is the torque analysis disturbance; if the difference value between the second torque and the second optimization torque has exceeded the set threshold value, the disturbance is the torque filtering disturbance;If the difference between the third torque and the third optimization torque exceeds the set threshold, the fault is the torque arbitration fault; if the difference between the third torque and the actual output torque exceeds the set threshold, the fault is the torque output fault.

[0034] Finally, the torque is regulated according to the type of fault of the control device for the whole vehicle, so that a corresponding fault regulation torque is generated, the above-mentioned fault regulation torque can also be different according to the current vehicle condition.

[0035] In the method for torque monitoring of the electric motor according to the present embodiment, the optimized analysis of a torque as the simplified analysis of a torque, the optimized filtering of a torque as the simplified filtering of a torque, the optimized decision about a torque as the simplified decision about a torque are carried out separately.

[0036] In the method for torque monitoring of the electric vehicle according to the present embodiment, the step of calculating the torque limit value according to the vehicle operation signal, the vehicle state signal and the capability of the components comprises the following two parts: Firstly, based on the vehicle operating signal, the vehicle status signal and the capability of the components, the maximum and minimum values ​​of the current deliverable torque are calculated; Secondly, after changing the torque, a gradient is calculated and a gradient limit value is determined.

[0037] In the torque monitoring method of the electric vehicle according to the present embodiment, a comparison of the requested torque with the torque limit is performed, and the requested torque is limited within the range of the torque limit, and the output torque is obtained, the step of which includes: a comparison is made between the maximum and minimum values ​​of the current deliverable torque and the requested torque; if the requested torque is within the range, the requested torque is delivered; otherwise, the maximum value is delivered if the requested torque is greater than the maximum value; and the minimum value is delivered if the requested torque is less than the minimum value; When the required torque is changed, it is raised or lowered smoothly and evenly according to the gradient limit value. No sudden changes occur, thus ensuring safe and smooth driving. An appropriate gradient limit value is selected according to requirements. The gradient limit value is determined by a specialist in this field based on the road surface conditions and vehicle speed, in conjunction with other current vehicle operating conditions. Example 2:

[0038] In the present embodiment, a system for torque monitoring of the electric vehicle is specified, which serves to carry out the above-mentioned torque monitoring method, comprising: - an actual torque calculation unit in which the vehicle operation signal and the vehicle status signal are detected, and the actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle status signal; the actual torque calculation unit comprises: - a torque analysis module: the first torque is determined by analyzing the current torque received from the control device for the entire vehicle according to the vehicle operation signal and the vehicle status signal; - a torque filtering module: the flat and smooth second torque is determined by filtering the first torque; - a torque arbitration module: the third torque is determined by deciding the second torque according to the maximum traction torque of the electric motor and the maximum power generation torque of the electric motor; - a torque output module: the actual output torque is determined by the torque output processing of the third torque; - a calculation unit for the fault adjustment torque: it is assessed whether a fault exists; if a fault exists, the fault adjustment torque is generated according to the type of fault. The calculation unit for the fault adjustment torque includes: - a module for torque optimization generation; - an assessment module; - a fault diagnosis module and - a system protection module.

[0039] The torque optimization generation module consists of: - a torque analysis optimization sub-module in which a first optimized torque is determined by the torque analysis optimization processing; - a torque filtering optimization sub-module in which a second optimized torque is determined by the torque filtering optimization processing, and - a torque arbitration optimization submodule; in which a third optimized torque is determined by the torque arbitration optimization processing.

[0040] The assessment module is designed as a comparator and includes: - a first assessment sub-module in which a comparison of said first torque with said first optimized torque is carried out; - a second assessment sub-module in which a comparison of said second torque with said second optimized torque is carried out; - a third assessment sub-module in which a comparison of said third torque with said third optimized torque is carried out, and - a fourth assessment sub-module in which a comparison of the actual output torque with the third torque is carried out.

[0041] The fault diagnosis module is used to judge whether a fault exists and to judge the type of fault; if the said difference value is smaller than the set threshold, it is judged that the actual torque is OK; if the said difference value is greater than the set threshold, it is judged that a system fault exists, and the type of fault is judged according to the torque with the existing difference value.

[0042] The system protection module is used to regulate the torque according to the type of fault and to generate a fault-regulating torque. The system protection module reduces the torque of the electric motor according to the current vehicle condition and the type of fault, or the vehicle's journey is terminated, thus ensuring safe travel. - a requested torque output unit: if the system is OK, the actual output torque of the electric motor is used as the requested torque, otherwise the fault regulation torque is used as the requested torque; - A limit value calculation unit: the torque limit is calculated based on the vehicle operating signal, the vehicle status signal, and the component capability. The limit value calculation unit includes a torque limit calculation module and a torque change limit module. The torque limit calculation module calculates the maximum and minimum values ​​of the current output torque; the torque change limit module calculates the gradient based on the torque change, and a gradient limit is determined. - a limit value output unit: a comparison of the requested torque with the specified torque limit is performed, the requested torque is limited within the torque limit range, and the output torque is maintained. The specified limit value output unit comprises: - an upper and lower limit processing module, in which a comparison of the maximum and minimum values ​​of the current deliverable torque with the value of the requested torque is carried out; the requested torque is delivered if the requested torque is within this range, otherwise the said maximum value is delivered if the requested torque is greater than the said maximum value, and the said minimum value is delivered if the requested torque is less than the said minimum value; - a change limit value processing module, in which the value of the requested torque is raised or lowered evenly and smoothly according to the size of the gradient limit value when the value of the requested torque is changed, whereby no sudden change of the torque occurs, so that the safety and smoothness of the vehicle's travel is ensured.

[0043] In the torque monitoring system of the electric vehicle according to the present embodiment, the torque analysis optimization sub-module as the simplified torque analysis module, the torque filtering optimization sub-module as the simplified torque filtering module, and the torque arbitration optimization sub-module as the simplified torque arbitration module are separately implemented.

Claims

[1] Method for torque monitoring of the electric vehicle, characterized by that the procedure includes the following steps: - a vehicle operation signal and a vehicle state signal are detected, and an actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle state signal; - it is judged whether a fault exists in the control system for the entire vehicle, and a fault regulating torque is generated according to the type of fault if the fault exists; - if the control system for the whole vehicle is OK, an actual output torque of the electric motor is used as a requested torque, otherwise the said fault regulation torque is used as the requested torque; - a torque limit is calculated based on the vehicle operating signal, the vehicle status signal and the capability of the components by calculating a maximum and a minimum value of the current deliverable torque based on the vehicle operating signal, the vehicle status signal and the capability of the components, and calculating a corresponding gradient based on the change in the torque and determining a gradient limit; - a comparison of the requested torque with the said torque limit is carried out, and the requested torque is limited within the range of the torque limit, and an output torque is obtained by comparing the maximum and minimum values ​​of the deliverable torque with the said requested torque; if the requested torque is within this range, the requested torque is delivered, otherwise the maximum value is delivered if the requested torque is greater than the said maximum value; and the minimum value is delivered if the requested torque is less than the minimum value; and when the requested torque is varied, it is raised or lowered evenly and smoothly according to the size of the gradient limit. [2] Method for monitoring the torque of the electric vehicle according to claim 1, characterized bythat the step for calculating the actual torque of the electric motor includes: - a first torque is obtained by analyzing a torque; - a second torque is then obtained by filtering, and - a third torque is obtained by a decision on a torque, - an actual output torque is finally obtained by a torque output. [3] Method for torque monitoring of the electric vehicle according to claim 1 or 2, characterized by that it is judged whether a fault exists in the control system for the entire vehicle; and a fault regulating torque is generated if a fault exists; the step of doing so comprising: - a first optimized torque is obtained by an optimized analysis of a torque, a second optimized torque is obtained by an optimized filtering of the first torque, a third optimized torque is obtained by a decision on the second torque; - a comparison of the first torque with the first optimized torque, a comparison of the second torque with the second optimized torque, a comparison of the third torque with the third optimized torque, and a comparison of the third torque with the actual output torque are performed separately, and their difference value is obtained; - if the difference value is smaller than the set threshold, it is judged that the actual torque is OK; if the difference value is larger than the set threshold, it is judged that there is a system fault, and according to the torque with the existing difference value, the type of fault is judged; - the torque is regulated according to the type of disturbance so that a disturbance regulation torque is generated. [4] Method for monitoring the torque of the electric vehicle according to claim 3, characterized by that the optimized analysis of a torque, the optimized filtering of a torque, the optimized decision about a torque are carried out separately as the simplified analysis, the simplified filtering and the simplified decision about a torque. [5] Electric vehicle torque monitoring system, characterized by that the system includes: - a calculation unit for an actual torque: a vehicle operation signal and a vehicle state signal are detected, and the actual torque of the electric motor is calculated according to the vehicle operation signal and the vehicle state signal; - a calculation unit for a disturbance adjustment torque: it is judged whether a disturbance exists; if a disturbance exists, the disturbance adjustment torque is generated according to the type of disturbance; - a requested torque output unit: if the system is OK, an actual output torque of the electric motor is used as the requested torque, otherwise the fault regulation torque is used as the requested torque; - a limit value calculation unit: the torque limit is calculated based on the vehicle control signal, the vehicle condition signal, and the component capability, the limit value calculation unit comprising a torque limit calculation module and a torque change limit module, in which the torque limit calculation module calculates a maximum and a minimum value of the current deliverable torque based on the vehicle control signal, the vehicle condition signal, and the component capability; in which the torque change limit module calculates a gradient based on the torque change, and a gradient limit is determined; - a limit value output unit: a comparison of the requested torque with the specified torque limit is carried out, and the requested torque is limited within the range of the torque limit, so that an output torque is obtained, wherein said limit value output unit comprises an upper and lower limit value processing module and a change limit value processing module, in which the upper and lower limit value processing module compares the maximum and minimum values ​​of the current deliverable torque with the value of the requested torque, the requested torque is delivered if the requested torque is within this range, otherwise said maximum value is delivered if the requested torque is greater than said maximum value, and said minimum value is delivered,If the requested torque is less than the specified minimum value, the processing module for the change limit value raises or lowers it evenly and smoothly according to the size of the gradient limit value when the value of the requested torque is changed. [6] Electric vehicle torque monitoring system according to claim 5, characterized by that the unit of account for the actual torque includes: - a torque analysis module: a first torque is obtained by analyzing the current torque; - a torque filtering module: a second torque is obtained by filtering; - a torque arbitration module: a third torque is obtained by a decision on a torque; - a torque output module: an actual output torque is obtained by a torque output. [7] Electric vehicle torque monitoring system according to claim 5, characterized by that the unit of account for the disturbance regulation torque includes: - a torque optimization generation module comprising: - a torque analysis optimization sub-module in which a first optimized torque is obtained by an optimized analysis of a torque; - a torque filtering optimization sub-module in which a second optimized torque is obtained by optimized filtering of a torque; - a torque arbitration optimization sub-module in which a third optimized torque is obtained by an optimized decision on a torque; - an assessment module that includes: - a first assessment sub-module in which a comparison of said first torque with said first optimized torque is carried out; - a second assessment sub-module in which a comparison of said second torque with said second optimized torque is carried out; - a third assessment sub-module in which a comparison of said third torque with said third optimized torque is carried out; - a fourth assessment sub-module in which a comparison of the actual output torque with the third torque is carried out; - a fault diagnosis module for judging that the actual torque is normal if said difference value is less than the set threshold; for judging that there is a fault in the control system for the entire vehicle if said difference value is greater than the set threshold, and for judging the type of fault according to the torque with the existing difference value; - a system protection module in which the torque is regulated according to the type of fault and a fault regulation torque is generated. [8] Electric vehicle torque monitoring system according to claim 7, characterized by that the torque analysis optimization submodule is implemented as the simplified torque analysis module, the torque filtering optimization submodule is implemented as the simplified torque filtering module, and the torque arbitration optimization submodule is implemented as the simplified torque arbitration module.

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