Control method and control system for electric drive vehicle

Abstract

The present invention provides a control method and control system for an electric drive vehicle, belonging to the field of new energy vehicles. The method comprises: obtaining the motor speed and the current value of the motor in real time; determining the climbing condition of the vehicle according to the motor speed and the current value of the motor; calculating the climbing condition as the driving current of the vehicle in a uniform speed driving state in the climbing mode; when receiving the driving pedal recovery completion instruction and determining that the enabling state of the motor controller meets the first preset condition, calculating the acceleration of the current vehicle according to the current vehicle speed and determining the PI parameter; responding to the vehicle pedal action instruction, determining that the vehicle pedal action instruction is a vehicle starting instruction, using the driving current in the uniform speed driving state as a feedforward value to perform proportional integral speed regulation on the motor, until the actual current value of the motor is greater than the feedforward value, and outputting the release instruction of the ramp electromagnetic brake, wherein the proportional integral adjustment parameter is the PI parameter. The present invention realizes fast and smooth starting on different slopes.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to a control method for an electric drive vehicle and a control system for an electric drive vehicle. Background Art

[0002] With the promotion of new energy vehicles, electric drive technology is increasingly being used in the automotive field. When a vehicle stops and then restarts while climbing a slope, the driver needs to release the brake and immediately step on the accelerator, otherwise the vehicle will slide backwards under the action of its own gravity. For unskilled drivers, they are often in a rush and prone to accidents. Since the torque output of the motor has the characteristic of fast response, electric drive vehicles (such as pure electric vehicles and hybrid electric vehicles) often apply a driving force that can balance the vehicle's slope resistance in the opposite direction of the vehicle's backward slide by stalling the motor, so that the vehicle can remain stationary on the slope.

[0003] Electric-drive vehicles (such as electric-drive engineering vehicles) drive the wheels through two wheel-side motors to achieve vehicle travel. During driving, the speed push rod and enable pedal instructions are collected and converted into the required speed of the drive motor. The required speed is smoothed, limited, and processed to obtain a speed control command. The motor controller then controls the motor according to a certain algorithm, so that the drive motor outputs according to the speed command, ultimately achieving vehicle travel.

[0004] Furthermore, the electric-drive engineering vehicles among the current electric-drive vehicles have the characteristics of large load, large load changes and complex working conditions, which require high safety performance of electric-drive engineering vehicles. The existing anti-slipping methods all adopt software control methods, that is, the speed and torque signals are used to judge the sliding working conditions of the vehicle, and the motor is controlled to output zero speed to stop on the slope. When it is necessary to start, the motor command is PI controlled according to the actual speed of the motor, and the vehicle is controlled by gradually increasing the motor torque and torque change rate to exit the sliding state. Although the existing technical solutions can assist the slope to a certain extent, these solutions are subject to the stall characteristics of the motor (the working condition of torque output when the motor runs at zero speed). The time for keeping the vehicle stationary on the slope by stalling the motor cannot be too long, otherwise it may cause excessive temperature rise and thus damage the motor, or the motor cannot output enough torque due to self-protection, causing the vehicle to slip backward and cause a safety accident. Summary of the invention

[0005] The purpose of the embodiments of the present invention is to provide a control method for an electric drive vehicle and a control system for an electric drive vehicle, so as to at least solve the problem that the start-stop performance of the electric drive vehicle on a slope is not high.

[0006] In order to achieve the above object, the present invention provides a control method for an electric drive vehicle in a first aspect, the method comprising:

[0007] Obtain the driving current of the vehicle in the climbing mode and at a constant speed;

[0008] In response to a vehicle pedal action command and when it is determined that the vehicle pedal action command is a vehicle start command, the drive current under the uniform speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then a release command of the ramp electromagnetic brake is output to control the ramp electromagnetic brake to perform a corresponding action.

[0009] Optionally, the proportional integral adjustment parameter is a PI parameter; the PI parameter is determined by the following steps:

[0010] When a driving pedal recovery completion instruction is received and it is determined that the enabling state of the motor controller meets the first preset condition, the current vehicle speed is obtained and the acceleration of the current vehicle is calculated according to the current vehicle speed; and the PI parameter is determined according to the acceleration of the vehicle.

[0011] Optionally, obtaining the driving current of the vehicle in a climbing mode and a state where the vehicle is traveling at a constant speed includes:

[0012] Get the motor speed and current value in real time;

[0013] The climbing condition of the vehicle is determined according to the motor speed and the current value of the motor; when it is determined that the climbing condition of the vehicle is the climbing mode:

[0014] If it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated.

[0015] Optionally, the method further includes:

[0016] When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction;

[0017] If it is determined that the enabling state of the motor controller meets the first preset condition, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

[0018] Optionally, determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor includes:

[0019] When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x;

[0020] Obtaining the duration of the first state before resetting;

[0021] When it is determined that the duration of the first state before resetting is greater than a first set value, it is determined that the climbing condition of the vehicle is a climbing mode.

[0022] Optionally, the determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor further includes:

[0023] Based on the motor speed and the motor current value, controlling the transformation of the second state, wherein the transformation mode includes maintaining and resetting;

[0024] Obtaining the duration of the second state before resetting;

[0025] When it is determined that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than a second set value, it is determined that the climbing condition of the vehicle is the non-climbing mode.

[0026] Optionally, controlling the transformation of the second state based on the motor speed and the motor current value includes:

[0027] When the motor speed and the motor current value meet the third preset condition, the second state is maintained; when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

[0028] Optionally, if it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated, including:

[0029] The speed difference of the motor is calculated. When it is determined that the speed difference of the motor is less than the set value, it is determined that the vehicle is in a uniform speed driving state in the current climbing mode, and the average current value of the motor in the uniform speed driving state is used as the driving current in the uniform speed driving state.

[0030] Optionally, determining that the enabling state of the motor controller satisfies a first preset condition includes:

[0031] Get the enable status of the motor controller in real time;

[0032] Under the condition that the driving pedal recovery completion instruction is received, when the enable state of the motor controller is determined to be changed from the output position to the stop position according to the enable state of the motor controller at the current moment and the enable state of the motor controller at the previous moment, it is determined that the enable state of the motor controller meets the first preset condition.

[0033] Optionally, determining that the vehicle pedal action instruction is a vehicle start instruction includes:

[0034] Obtaining a vehicle start judgment signal;

[0035] When it is determined that the vehicle start judgment signals all meet corresponding conditions, the vehicle pedal action command is determined to be a vehicle start command.

[0036] Optionally, the vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal;

[0037] When it is determined that the state of the ramp electromagnetic brake is the braking state, the enable state of the motor controller is the output position, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions.

[0038] The present invention also provides a control system for an electric drive vehicle, the control system comprising:

[0039] a hill start sign determination module, for responding to a vehicle pedal action instruction and determining whether the vehicle pedal action instruction is a vehicle start instruction;

[0040] The hill start control module is used to obtain the driving current of the vehicle in the climbing mode and the vehicle is in a constant speed driving state; and when the hill start sign judgment module determines that the vehicle pedal action instruction is a vehicle start instruction, the driving current of the vehicle in the constant speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then output a release instruction of the ramp electromagnetic brake to control the ramp electromagnetic brake to perform the corresponding action.

[0041] Optionally, the proportional integral adjustment parameter is a PI parameter; the control system further includes:

[0042] The ramp electromagnetic brake enable judgment module is used to obtain the current vehicle speed and calculate the acceleration of the current vehicle according to the current vehicle speed when receiving the driving pedal recovery completion instruction and determining that the enable state of the motor controller meets the first preset condition; and determine the PI parameter according to the acceleration of the vehicle.

[0043] Optionally, the control system further includes:

[0044] A vehicle climbing condition judgment module is used to obtain the motor speed and the motor current value in real time, and determine the vehicle climbing condition according to the motor speed and the motor current value;

[0045] The current capture module is used to determine whether the vehicle is in a uniform driving state in the current climbing mode according to the current motor speed and the current value of the motor when the vehicle climbing condition judgment module determines that the vehicle's climbing condition is the climbing mode, and calculate the driving current in the uniform driving state when it is determined that the vehicle is in a uniform driving state.

[0046] Optionally, the ramp electromagnetic brake enable judgment module is also used for:

[0047] When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction;

[0048] If it is determined that the enabling state of the motor controller meets the first preset condition, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

[0049] Optionally, in the control system of the electric drive vehicle, determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor includes:

[0050] When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x;

[0051] Obtaining the duration of the first state before resetting;

[0052] When it is determined that the duration of the first state before resetting is greater than a first set value, it is determined that the climbing condition of the vehicle is a climbing mode.

[0053] Optionally, in the control system of the electric drive vehicle, the step of determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor further includes:

[0054] Based on the motor speed and the motor current value, controlling the transformation of the second state, wherein the transformation mode includes maintaining and resetting;

[0055] Obtaining the duration of the second state before resetting;

[0056] When it is determined that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than a second set value, it is determined that the climbing condition of the vehicle is the non-climbing mode.

[0057] Optionally, controlling the transformation of the second state based on the motor speed and the motor current value includes:

[0058] When the motor speed and the motor current value meet the third preset condition, the second state is maintained; when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

[0059] Optionally, in the control system of the electric drive vehicle, if it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated, including:

[0060] The speed difference of the motor is calculated. When it is determined that the speed difference of the motor is less than the set value, it is determined that the vehicle is in a uniform speed driving state in the current climbing mode, and the average current value of the motor in the uniform speed driving state is used as the driving current in the uniform speed driving state.

[0061] Optionally, in the control system of the electric drive vehicle, determining that the enabling state of the motor controller satisfies a first preset condition includes:

[0062] Get the enable status of the motor controller in real time;

[0063] Under the condition that the driving pedal recovery completion instruction is received, when the enable state of the motor controller is determined to be changed from the output position to the stop position according to the enable state of the motor controller at the current moment and the enable state of the motor controller at the previous moment, it is determined that the enable state of the motor controller meets the first preset condition.

[0064] Optionally, in the control system of the electric drive vehicle, determining that the vehicle pedal action instruction is a vehicle start instruction includes:

[0065] Obtaining a vehicle start judgment signal;

[0066] When it is determined that the vehicle start judgment signals all meet corresponding conditions, the vehicle pedal action command is determined to be a vehicle start command.

[0067] Optionally, in the control system of the electric drive vehicle, the vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal;

[0068] When it is determined that the state of the ramp electromagnetic brake is the braking state, the enable state of the motor controller is the output position, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions.

[0069] On the other hand, the present invention provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable the machine to execute the above-mentioned control method for an electric drive vehicle. Through the above-mentioned technical solution, when it is determined that the vehicle needs to start on a slope, that is, the vehicle pedal action instruction is determined to be a vehicle starting instruction, and the driving current under the uniform speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then the ramp electromagnetic brake release instruction is output to control the execution action of the ramp electromagnetic brake. Through the control logic of the present application, the control parameters of the vehicle that needs to start on a slope are adapted to the slope, which improves the performance of the vehicle's ramp start, can achieve fast and smooth starting on different slopes, reduce backward slippage, and improve safety.

[0070] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0072] Figure 1 It is a schematic diagram of a feedforward value capture process of a motor current in a control method of an electric drive vehicle provided by an embodiment of the present invention;

[0073] Figure 2 It is a schematic diagram of a process flow of judging a hill climbing condition in a control method of an electric drive vehicle provided by an embodiment of the present invention;

[0074] Figure 3 It is a schematic diagram of braking logic of electromagnetic braking on a slope in a control method of an electric drive vehicle provided by an embodiment of the present invention;

[0075] Figure 4 It is a schematic diagram of vehicle starting instruction judgment logic in a control method of an electric drive vehicle provided by an embodiment of the present invention;

[0076] Figure 5 It is a logic schematic diagram of a control method for an electric drive vehicle provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0077] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0078] In this embodiment, the electric drive vehicle is preferably an electric drive engineering vehicle; an electromagnetic brake is provided on the electric drive engineering vehicle to cooperate with the brake disc for braking. The working principle of the electromagnetic brake is that when the excitation coil is connected to the rated voltage (DC), the electromagnetic force attracts the armature, so that the armature pushes the spring to separate (release) the flange from the brake disc. At this time, the transmission shaft operates or starts normally with the brake disc. When the transmission system is separated or powered off, the brake is also powered off at the same time. At this time, the spring applies pressure to the armature, forcing the friction torque between the brake disc, the armature and the flange to stop the transmission shaft quickly.

[0079] An embodiment of the present invention provides a control method for an electric drive vehicle. The control method comprises:

[0080] Obtain the driving current of the vehicle in the climbing mode and at a constant speed;

[0081] In response to the vehicle pedal action command, and when it is determined that the vehicle pedal action command is a vehicle start command, the drive current in the uniform speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then the ramp electromagnetic brake release command is output to control the ramp electromagnetic brake to perform the corresponding action. When the above control method is specifically applied to an electric drive engineering vehicle, the drive current in the uniform speed driving state of the vehicle is added to the current regulation process, which can make the starting process respond faster and adapt to the starting characteristics of the electric drive engineering vehicle, prevent the electric drive engineering vehicle from slipping due to heavy load, and improve the safety of the electric drive engineering vehicle.

[0082] Preferably, the proportional integral adjustment parameter is a PI parameter; the PI parameter is determined by the following steps:

[0083] When a driving pedal recovery completion instruction is received and it is determined that the enabling state of the motor controller meets the first preset condition, the current vehicle speed is obtained and the acceleration of the current vehicle is calculated according to the current vehicle speed; and the PI parameter is determined according to the acceleration of the vehicle.

[0084] Preferably, the step of obtaining the driving current of the vehicle in a climbing mode and when the vehicle is traveling at a constant speed includes:

[0085] Get the motor speed and current value in real time;

[0086] The climbing condition of the vehicle is determined according to the motor speed and the current value of the motor; when it is determined that the climbing condition of the vehicle is the climbing mode:

[0087] If it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated.

[0088] Specifically, when the vehicle needs to start on a slope, that is, when the vehicle is in a climbing mode, a vehicle start judgment signal is obtained; when it is determined that the vehicle start judgment signal meets the corresponding conditions, the vehicle pedal action instruction is determined to be a vehicle start instruction. Figure 4 As shown, the vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal; when it is determined that the state of the ramp electromagnetic brake is the brake state, the enable state of the motor controller is the output bit, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions. When the vehicle pedal action instruction is determined to be the vehicle start instruction, the speed loop is entered. At this time, the PI parameters of the speed loop are adaptively selected according to the acceleration calculated on the same ramp, that is, when the acceleration value on the large ramp is large, a group of relatively large PI parameters are selected to enable the vehicle to start quickly and reduce the backward slip; when the acceleration value on the small ramp is small, a group of relatively small PI parameters are selected to enable the vehicle to start smoothly and reduce the impact. The acceleration calculated on the same ramp has a corresponding relationship with the PI parameter; the corresponding relationship forms a two-dimensional table according to the calibration of the optimal PI parameters of different ramps (that is, different accelerations); in use, the optimal PI parameters can be quickly obtained by the calculated acceleration on the ramp. When the speed loop is running and adjusting, the driving current of the vehicle in the same climbing mode (same slope) at a constant speed before the vehicle starting command is determined as the feedforward value to speed up the speed loop response and reduce the vehicle's backward slip distance. Figure 1 As shown, preferably, the driving current of the vehicle in a uniform driving state is: the speed difference of the motor is calculated, and when it is determined that the speed difference of the motor is less than the set value, it is determined that the vehicle is in a uniform driving state in the current climbing mode, and the average value of the current value of the motor in the uniform driving state is used as the driving current in the uniform driving state. In this way, the accuracy of the driving current is improved, and the feedforward value of the current slope can be better adapted.

[0089] When the motor current value (the detected motor current is the actual output current) is greater than the feedforward value, the electromagnetic brake is enabled to 0, the electromagnetic brake output current is controlled (the electromagnetic brake engages the brake pad, the brake is released, and the vehicle can drive normally), and the motor controller performs speed control output. During the start-up process, when the speed loop is controlled, the corresponding PI parameter group is selected according to the slope estimator to perform a fast speed response and reduce the slope distance.

[0090] Release the brake pedal to start the vehicle on a slope. At this time, since the feedforward value already has a certain current value and the PI parameters are adapted according to the slope (acceleration), the vehicle can start quickly and smoothly, reducing the slippage. Further, when the above control method is applied to an electric drive engineering vehicle, the PI parameters are determined according to the acceleration of the electric drive engineering vehicle, so that the PI parameters can adapt to the real-time working conditions, making the PI parameters more suitable for the working conditions and loads of the current electric drive engineering vehicle, solving the safety problems caused by the large load changes and complex working conditions of the electric drive engineering vehicle, and improving the safety performance of the electric drive engineering vehicle.

[0091] like Figure 2 As shown, the control method of the electric drive vehicle further includes:

[0092] When it is determined that the vehicle's climbing condition is a climbing mode, the current vehicle driving direction control instruction is obtained; if it is determined that the enable state of the motor controller meets the first preset condition, and the current vehicle driving direction control instruction is inconsistent with the current motor speed, the control instruction of the slope electromagnetic brake is output to control the execution action of the slope electromagnetic brake.

[0093] Preferably, the logic for determining whether the motor controller's enable state meets the first preset condition is: obtaining the motor controller's enable state in real time; upon receiving the driving pedal recovery completion instruction, determining that the motor controller's enable state changes from the output position to the stop position based on the motor controller's enable state at the current moment and the motor controller's enable state at the previous moment, and determining that the motor controller's enable state meets the first preset condition. Figure 3 As shown, when the vehicle's climbing condition is the climbing mode, that is, when the vehicle's climbing flag is 1, the enable status of the motor controller is obtained and stored in real time. If the enable status of the motor controller is 0 at the current moment, it means that the electromagnetic brake is not powered. The enable status of the motor controller at the previous moment is 1, which means that the electromagnetic brake is powered. It is determined that the enable status of the motor controller meets the first preset condition.

[0094] Preferably, the above-mentioned control method of the electric drive vehicle further includes:

[0095] When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction;

[0096] If it is determined that the enabling state of the motor controller meets the first preset condition, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

[0097] Specifically, in a possible embodiment, as Figure 3The vehicle driving direction control command shown can detect the position of the motor enable control pedal of the vehicle through the sensor. For example, when the driver releases the motor enable control pedal, when the motor enable control pedal is detected to be reset, and when the gear is detected to be in the forward gear, it is determined that the vehicle driving direction control command is in the forward direction. When the vehicle climbing condition is in the climbing mode, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control command is inconsistent with the current motor speed, such as the vehicle speed is backward and the vehicle driving direction control command is in the forward direction, and the motor speed is in the negative direction, it can be considered that the vehicle is sliding down the slope. At this time, the slope electromagnetic brake enable position is 1, the electromagnetic brake is activated, and the vehicle actively stops on the slope. The introduction of the condition that the current vehicle acceleration is greater than the set value can prevent frequent parking brakes of the vehicle.

[0098] In a possible embodiment, Figure 5 As shown, when the motor control pedal is completely reset, that is, the motor control pedal is enabled to zero, and the vehicle speed is less than the set value S, that is, the current vehicle driving direction control command is inconsistent with the current motor speed, the ramp electromagnetic brake control command will also be output as a brake command. Preferably, after the driver releases the enabling control pedal, when the motor enabling control pedal is detected to be reset, and when the gear of the vehicle is detected to be in the forward gear, and the motor speed changes from positive to negative, and lasts for a certain period of time, the electromagnetic brake is controlled to stop outputting current (when current passes through the electromagnetic brake magnetic coil, the electromagnetic force attracts the brake pad, and the brake pad is used to release the brake disc. At this time, the motor operates normally with the brake disc; when there is no current, the spring presses on the armature, forcing the brake disc and the armature and the flange to generate a friction torque, so that the transmission shaft stops quickly), so that the vehicle stops on the slope, and the motor controller has no current output at this time, and the vehicle can stay on the slope for a long time. The condition of lasting a certain period of time is introduced into the judgment to ensure that the vehicle is in the same climbing mode and avoids the flat ground speed fluctuation from mistakenly entering the parking brake control state.

[0099] like Figure 2 As shown, in order to make the determination of the climbing condition conform to the specific usage scenario, that is, to prevent the state of the climbing condition from being continuously switched under a critical state. The method of determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor includes:

[0100] When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x;

[0101] Obtain the duration of the first state before resetting; when it is determined that the duration of the first state before resetting is greater than the first set value, determine that the climbing condition of the vehicle is the climbing mode. The first state used in this embodiment is a state quantity used to characterize whether the motor speed and / or the current value of the motor meets the second preset condition. Preferably, the duration of the first state before resetting is determined by counting. When the current value of the motor is greater than the calibration value y and the motor speed is less than the calibration value x, counting starts, and the counting result K is judged in real time, wherein when it is detected that the current value of the motor is less than the calibration value y or when the motor speed is greater than the calibration value x, the counting result K will be cleared; the first state is the counting state; the first state is reset to the state where the counting result K is cleared. Only when the counting result K is greater than the first set value m, it is determined that the climbing condition of the vehicle is the climbing mode, that is, the vehicle climbing flag is set to 1.

[0102] Based on the motor speed and the motor current value, the transformation of the second state is controlled, and the transformation method includes maintaining and resetting; obtaining the duration of the second state before resetting; determining that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than the second set value, determining that the climbing condition of the vehicle is the non-climbing mode. The second state used in this embodiment is a state quantity used to characterize whether the motor speed and / or the motor current value meets the third preset condition.

[0103] Preferably, the transformation of the second state is controlled based on the motor speed and the motor current value, including: when the motor speed and the motor current value meet the third preset condition, the second state is maintained, and when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

[0104] Preferably, the duration of the second state before resetting is determined by counting. When the current value of the electric motor is less than the calibration value y or when the motor speed is greater than the calibration value x, counting starts, and the counting result M is judged in real time, wherein when it is detected that the current value of the motor is greater than the calibration value y and the motor speed is less than the calibration value x, the counting result M is cleared; the second state is the counting state; the second state is reset to the state where the counting result M is cleared. Only when the counting result M is greater than the second set value n and the current vehicle climbing condition is the climbing mode, the vehicle climbing condition is modified to the non-climbing mode, that is, the vehicle climbing flag is set to 0.

[0105] When the climbing mode is changed to the non-climbing mode, the condition for determining the second set value n is added, and hysteresis processing is performed to avoid frequent jumping of the climbing flag and improve the safety of the system.

[0106] Corresponding to the above-mentioned control method of the electric drive vehicle, the present invention further provides a control system of the electric drive vehicle, and the working principle will not be described in detail below. The control system includes:

[0107] The present invention also provides a control system for an electric drive vehicle, the control system comprising:

[0108] a hill start sign determination module, for responding to a vehicle pedal action instruction and determining whether the vehicle pedal action instruction is a vehicle start instruction;

[0109] The hill start control module is used to obtain the driving current of the vehicle in the climbing mode and the vehicle is in a constant speed driving state; and when the hill start sign judgment module determines that the vehicle pedal action instruction is a vehicle start instruction, the driving current of the vehicle in the constant speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then output a release instruction of the ramp electromagnetic brake to control the ramp electromagnetic brake to perform the corresponding action.

[0110] Preferably, the proportional integral adjustment parameter is a PI parameter; the control system further comprises:

[0111] The ramp electromagnetic brake enable judgment module is used to obtain the current vehicle speed and calculate the acceleration of the current vehicle according to the current vehicle speed when receiving the driving pedal recovery completion instruction and determining that the enable state of the motor controller meets the first preset condition; and determine the PI parameter according to the acceleration of the vehicle.

[0112] Preferably, the control system further comprises:

[0113] A vehicle climbing condition judgment module is used to obtain the motor speed and the motor current value in real time, and determine the vehicle climbing condition according to the motor speed and the motor current value;

[0114] The current capture module is used to determine whether the vehicle is in a uniform driving state in the current climbing mode according to the current motor speed and the current value of the motor when the vehicle climbing condition judgment module determines that the vehicle's climbing condition is the climbing mode, and calculate the driving current in the uniform driving state when it is determined that the vehicle is in a uniform driving state.

[0115] Optionally, the ramp electromagnetic brake enable judgment module is also used for:

[0116] When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction;

[0117] If it is determined that the enabling state of the motor controller meets the first preset condition and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

[0118] Optionally, in the control system of the electric drive vehicle, determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor includes:

[0119] When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x;

[0120] Obtaining the duration of the first state before resetting;

[0121] When it is determined that the duration of the first state before resetting is greater than a first set value, it is determined that the climbing condition of the vehicle is a climbing mode.

[0122] Optionally, in the control system of the electric drive vehicle, the step of determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor further includes:

[0123] Based on the motor speed and the motor current value, controlling the transformation of the second state, wherein the transformation mode includes maintaining and resetting;

[0124] Obtaining the duration of the second state before resetting;

[0125] When it is determined that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than a second set value, it is determined that the climbing condition of the vehicle is the non-climbing mode.

[0126] Preferably, based on the motor speed and the motor current value, controlling the transformation of the second state includes:

[0127] When the motor speed and the motor current value meet the third preset condition, the second state is maintained; when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

[0128] Optionally, in the control system of the electric drive vehicle, if it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated, including:

[0129] The speed difference of the motor is calculated. When it is determined that the speed difference of the motor is less than the set value, it is determined that the vehicle is in a uniform speed driving state in the current climbing mode, and the average current value of the motor in the uniform speed driving state is used as the driving current in the uniform speed driving state.

[0130] Optionally, in the control system of the electric drive vehicle, determining that the enabling state of the motor controller satisfies a first preset condition includes:

[0131] Get the enable status of the motor controller in real time;

[0132] Under the condition that the driving pedal recovery completion instruction is received, when the enable state of the motor controller is determined to be changed from the output position to the stop position according to the enable state of the motor controller at the current moment and the enable state of the motor controller at the previous moment, it is determined that the enable state of the motor controller meets the first preset condition.

[0133] Optionally, in the control system of the electric drive vehicle, determining that the vehicle pedal action instruction is a vehicle start instruction includes:

[0134] Obtaining a vehicle start judgment signal;

[0135] When it is determined that the vehicle start judgment signals all meet corresponding conditions, the vehicle pedal action command is determined to be a vehicle start command.

[0136] Optionally, in the control system of the electric drive vehicle, the vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal;

[0137] When it is determined that the state of the ramp electromagnetic brake is the braking state, the enable state of the motor controller is the output position, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions.

[0138] An embodiment of the present invention further provides a machine-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the above-mentioned control method for an electric drive vehicle.

[0139] Those skilled in the art will understand that all or part of the steps in the method for implementing the above-mentioned embodiments can be completed by instructing the relevant hardware through a program, and the program is stored in a storage medium, including several instructions for making a single-chip microcomputer, a chip or a processor (processor) perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes.

[0140] The optional embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the technical concept of the embodiments of the present invention, the technical scheme of the embodiments of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the embodiments of the present invention will not further describe various possible combinations.

[0141] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the embodiments of the present invention, they should also be regarded as the contents disclosed in the embodiments of the present invention.

Claims

1. A control method for an electric drive vehicle, characterized in that: The method comprises: Get the motor speed and current value in real time; The climbing condition of the vehicle is determined according to the motor speed and the current value of the motor. When it is determined that the climbing condition of the vehicle is the climbing mode: Obtain the driving current of the vehicle in the climbing mode and at a constant speed; In response to a vehicle pedal action command, when it is determined that the vehicle pedal action command is a vehicle start command, the drive current in the uniform speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and a ramp electromagnetic brake release command is output to control the ramp electromagnetic brake to perform a corresponding action; Determining the climbing condition of the vehicle according to the motor speed and the current value of the motor includes: When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x; Obtaining the duration of the first state before resetting; When it is determined that the duration of the first state before resetting is greater than a first set value, it is determined that the climbing condition of the vehicle is a climbing mode.

2. The control method of an electric drive vehicle according to claim 1, characterized in that: The proportional integral adjustment parameter is a PI parameter; the PI parameter is determined by the following steps: When a driving pedal recovery completion instruction is received and it is determined that the enabling state of the motor controller meets the first preset condition, the current vehicle speed is obtained and the acceleration of the current vehicle is calculated according to the current vehicle speed; and the PI parameter is determined according to the acceleration of the vehicle.

3. The control method of an electric drive vehicle according to claim 1, characterized in that: The step of obtaining the driving current of the vehicle in a climbing mode and a state where the vehicle is traveling at a constant speed includes: If it is determined that the vehicle is in a constant speed driving state in the current climbing mode according to the current motor speed and the motor current value, the driving current in the constant speed driving state is calculated.

4. The control method of an electric drive vehicle according to claim 3, characterized in that: The method further comprises: When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction; If it is determined that the enabling state of the motor controller meets the first preset condition, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

5. The control method of an electric drive vehicle according to claim 1, characterized in that: The method of determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor also includes: Based on the motor speed and the motor current value, controlling the transformation of the second state, wherein the transformation mode includes maintaining and resetting; Obtaining the duration of the second state before resetting; When it is determined that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than a second set value, it is determined that the climbing condition of the vehicle is the non-climbing mode.

6. The control method of the electric drive vehicle according to claim 5, wherein the step of controlling the change of the second state based on the motor speed and the motor current value comprises: When the motor speed and the motor current value meet the third preset condition, the second state is maintained; when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

7. The control method of an electric drive vehicle according to claim 2, characterized in that: The step of determining whether the enabling state of the motor controller satisfies a first preset condition includes: Get the enable status of the motor controller in real time; Under the condition that the driving pedal recovery completion instruction is received, when the enable state of the motor controller is determined to be changed from the output position to the stop position according to the enable state of the motor controller at the current moment and the enable state of the motor controller at the previous moment, it is determined that the enable state of the motor controller meets the first preset condition.

8. The control method of an electric drive vehicle according to claim 1, characterized in that: The step of determining that the vehicle pedal motion instruction is a vehicle starting instruction includes: Obtaining a vehicle start judgment signal; When it is determined that the vehicle start judgment signals all meet corresponding conditions, the vehicle pedal action command is determined to be a vehicle start command.

9. The control method of an electric drive vehicle according to claim 8, characterized in that: The vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal; When it is determined that the state of the ramp electromagnetic brake is the braking state, the enable state of the motor controller is the output position, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions.

10. A control system for an electric drive vehicle, characterized in that: The control system comprises: a hill start sign determination module, for responding to a vehicle pedal action instruction and determining whether the vehicle pedal action instruction is a vehicle start instruction; The hill start control module is used to obtain the driving current of the vehicle in the climbing mode and the vehicle is in a constant speed driving state; and under the condition that the hill start sign judgment module determines that the vehicle pedal action instruction is the vehicle start instruction, the driving current of the vehicle in the constant speed driving state is used as a feedforward value to perform proportional integral speed regulation on the motor until the actual current value of the motor is greater than the feedforward value, and then output a ramp electromagnetic brake release instruction to control the ramp electromagnetic brake to perform a corresponding action; A vehicle climbing condition judgment module is used to obtain the motor speed and the motor current value in real time, and determine the vehicle climbing condition according to the motor speed and the motor current value; Determining the climbing condition of the vehicle according to the motor speed and the current value of the motor includes: When the motor speed and the motor current value meet the second preset condition, the first state is maintained; when the motor speed and the motor current value do not meet the second preset condition, the first state is reset; the second preset condition is that the motor current value is greater than the calibration value y and the motor speed is less than the calibration value x; Obtaining the duration of the first state before resetting; When it is determined that the duration of the first state before resetting is greater than a first set value, it is determined that the climbing condition of the vehicle is a climbing mode.

11. The control system according to claim 10, characterized in that: The proportional integral adjustment parameter is a PI parameter; the control system also includes: The ramp electromagnetic brake enable judgment module is used to obtain the current vehicle speed and calculate the acceleration of the current vehicle according to the current vehicle speed when receiving the driving pedal recovery completion instruction and determining that the enable state of the motor controller meets the first preset condition; and determine the PI parameter according to the acceleration of the vehicle.

12. The control system according to claim 10, characterized in that: The control system further comprises: The current capture module is used to determine whether the vehicle is in a uniform driving state in the current climbing mode according to the current motor speed and the current value of the motor when the vehicle climbing condition judgment module determines that the vehicle's climbing condition is the climbing mode, and calculate the driving current in the uniform driving state when it is determined that the vehicle is in a uniform driving state.

13. The control system according to claim 12, characterized in that: The ramp electromagnetic brake enabling judgment module is also used for: When it is determined that the climbing condition of the vehicle is a climbing mode, obtaining a current vehicle driving direction control instruction; If it is determined that the enabling state of the motor controller meets the first preset condition, and the current vehicle acceleration is greater than the set value and the current vehicle driving direction control instruction is inconsistent with the current motor speed, a ramp electromagnetic brake control instruction is output to control the execution action of the ramp electromagnetic brake.

14. The control system according to claim 10, characterized in that: The method of determining the climbing condition of the vehicle according to the current motor speed and the current value of the motor also includes: Based on the motor speed and the motor current value, controlling the transformation of the second state, wherein the transformation mode includes maintaining and resetting; Obtaining the duration of the second state before resetting; When it is determined that the current climbing condition of the vehicle is the climbing mode and the duration of the second state before resetting is greater than a second set value, it is determined that the climbing condition of the vehicle is the non-climbing mode.

15. The control system according to claim 14, characterized in that: The controlling the transformation of the second state based on the motor speed and the motor current value comprises: When the motor speed and the motor current value meet the third preset condition, the second state is maintained; when the motor speed and the motor current value do not meet the third preset condition, the second state is reset; the third preset condition is that the motor current value is less than the calibration value y or when the motor speed is greater than the calibration value x.

16. The control system according to claim 11, characterized in that: The step of determining whether the enabling state of the motor controller satisfies a first preset condition includes: Get the enable status of the motor controller in real time; Under the condition that the driving pedal recovery completion instruction is received, when the enable state of the motor controller is determined to be changed from the output position to the stop position according to the enable state of the motor controller at the current moment and the enable state of the motor controller at the previous moment, it is determined that the enable state of the motor controller meets the first preset condition.

17. The control system according to claim 10, characterized in that: The step of determining that the vehicle pedal motion instruction is a vehicle starting instruction includes: Obtaining a vehicle start judgment signal; When it is determined that the vehicle start judgment signals all meet corresponding conditions, the vehicle pedal action command is determined to be a vehicle start command.

18. The control system of the electric vehicle according to claim 17, characterized in that: The vehicle start judgment signal includes: the state of the ramp electromagnetic brake, the enable state of the motor controller, the motor speed and the vehicle fault signal; When it is determined that the state of the ramp electromagnetic brake is the braking state, the enable state of the motor controller is the output position, the motor speed is not equal to zero and the vehicle fault signal is normal, it is determined that the vehicle start judgment signal meets the corresponding conditions.

19. A machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the control method for an electric drive vehicle as claimed in any one of claims 1 to 9.

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