Vehicle control method and system

Abstract

The invention discloses a vehicle control method and system. The vehicle comprises a motor, a battery and a controller. The controller is connected between the battery and the motor, and the controller is used for converting electric power output by the battery; the control method of the vehicle is executed by the controller. The vehicle control method comprises the steps that when the duration that the output current of a battery is larger than the maximum current of the battery reaches a first preset duration, a current limiting adjustment strategy is started; and circularly executing the steps of determining a target regulating variable according to the current-limiting regulation strategy, regulating the maximum output value of a speed loop control strategy of the motor according to the target regulating variable, determining a target current according to the regulated maximum output value and the speed loop control strategy, and controlling the rotating speed of the motor according to the target current and a current loop control strategy. And the duration for starting the current-limiting adjustment strategy reaches a second preset duration. According to the technical scheme, components and a battery can be better protected, it is guaranteed that the motor does not run slowly, and therefore running of a vehicle is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a vehicle control method and system. Background Art

[0002] With the increasing severity of environmental pollution, the rapid rise of new energy, the rapid development of technologies such as battery energy storage, and the rapid development of vehicle electrification. The controller is the core component of electric vehicles, responsible for signal acquisition, logic analysis, and driving motor functions of the vehicle. More and more OEMs are beginning to pay attention to how to better protect it and extend its service life.

[0003] The controller includes an inverter circuit that can convert the DC power output by the battery into AC power to drive the motor. The inverter circuit includes power devices. As long as the vehicle is running, current will flow in or out through the power devices, so the heating of the power devices is inevitable.

[0004] At present, the vehicle protection strategy is to install temperature sensors near power devices to collect the temperature of power devices in real time and set thresholds. When the temperature reaches the threshold, the motor operation is restricted, thereby reducing the AC current flowing through the power devices, preventing temperature rise and increasing service life. However, the temperature on the DC side is not taken into consideration, and the battery and circuit components cannot be well protected. Moreover, directly restricting the motor operation will greatly reduce the power of the motor and affect the operation of the vehicle. Summary of the invention

[0005] The present invention provides a vehicle control method and system to solve the problem that the vehicle protection strategy cannot protect the battery and circuit components well and may affect the operation of the vehicle.

[0006] According to one aspect of the present invention, a method for controlling a vehicle is provided, wherein the vehicle comprises a motor, a battery and a controller; the controller is connected between the battery and the motor, and is used to convert the power output by the battery; the method for controlling the vehicle is executed by the controller;

[0007] The vehicle control method comprises:

[0008] When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, starting a current limiting regulation strategy;

[0009] The steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration.

[0010] Optionally, determining a target adjustment amount according to the current limiting adjustment strategy includes:

[0011] If the output current of the battery is less than or equal to the preset current, the target adjustment amount is determined to be the maximum adjustment amount; if the output current is greater than the preset current, the initial adjustment amount is determined according to the output current and the preset current and based on a proportional-integral control strategy;

[0012] If the initial adjustment amount is greater than the minimum adjustment amount, the initial adjustment amount is determined to be the target adjustment amount; if the initial adjustment amount is less than or equal to the minimum adjustment amount, the minimum adjustment amount is determined to be the target adjustment amount.

[0013] Optionally, the maximum adjustment amount is zero, and the minimum adjustment amount is a negative value.

[0014] Optionally, determining the initial adjustment amount according to the output current and based on a proportional-integral control strategy includes:

[0015] Multiplying the difference between the preset current and the current output current of the battery by a first proportional coefficient to obtain a first proportional term;

[0016] The product of the first proportional term and the first integral coefficient is added to the previous first integral term to obtain a current first integral term;

[0017] The first proportional term is added to the current first integral term to obtain the initial adjustment amount.

[0018] Optionally, the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including:

[0019] The timing starts when the current limiting regulation strategy is started;

[0020] The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy;

[0021] When the timing duration reaches a second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted.

[0022] Optionally, the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including:

[0023] The timing starts when the current limiting regulation strategy is started;

[0024] The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy;

[0025] If the vehicle is restarted before the timing duration reaches the second preset duration, the timing continues and the current limiting adjustment strategy continues to be executed after the vehicle is restarted, and when the timing duration reaches the second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted.

[0026] Optionally, the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including:

[0027] The timing starts when the current limiting regulation strategy is started;

[0028] The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy;

[0029] If the vehicle is turned off before the timing duration reaches the second preset duration, then when the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on is less than or equal to the preset difference, the timing continues and the current limiting regulation strategy continues to be executed, and when the timing duration reaches the second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted; wherein the historical temperature is the temperature of the controller when the current limiting regulation strategy is started;

[0030] When the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on is greater than the preset difference, the maximum output value of the speed loop control strategy is stopped from being adjusted.

[0031] Optionally, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy includes:

[0032] The adjusted maximum output value is used as a limit value, and the target current is determined according to a speed loop proportional-integral control strategy;

[0033] The target voltage of the motor is determined according to the target current and the current loop proportional-integral control strategy, and the motor is driven to operate according to the target voltage to control the rotation speed of the motor.

[0034] Optionally, the adjusted maximum output value is used as a limit value, and the target current is determined according to a speed loop proportional integral control strategy, including:

[0035] The difference between the actual speed of the motor and the target speed is multiplied by the second proportional coefficient to obtain a second proportional term, and the product of the second proportional term and the second integral coefficient is added to the previous second integral term to obtain a current second integral term, and the sum of the second proportional term and the current second integral term is used as the initial current;

[0036] When the initial current is less than the adjusted maximum output value, the initial current is used as the target current; when the initial current is greater than or equal to the adjusted maximum output value, the adjusted maximum output value is used as the target current;

[0037] Determining a target voltage of the motor according to the target current and a current loop proportional-integral control strategy, and driving the motor to operate according to the target voltage, including:

[0038] The difference between the actual current of the motor and the target current is multiplied by the third proportional coefficient to obtain a third proportional term, and the product of the third proportional term and the third integral coefficient is added to the previous third integral term to obtain a current third integral term, and the sum of the third proportional term and the current third integral term is used as the target voltage to drive the motor to operate.

[0039] According to another aspect of the present invention, a vehicle control system is provided, which includes: a motor, a battery and a controller; the controller is connected between the battery and the motor, and is used to convert the power output by the battery; the controller is used to execute the vehicle control method described in any embodiment of the present invention.

[0040] The technical solution of the embodiment of the present invention is to start the current limiting regulation strategy when the duration of the output current of the battery greater than the maximum current of the battery reaches a first preset duration, and cyclically execute the steps of determining the target adjustment amount according to the current limiting regulation strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy, until the duration of starting the current limiting regulation strategy reaches a second preset duration. The output value of the speed loop control strategy can be reduced, that is, the target current is reduced, thereby reducing the target voltage output by the current loop control strategy, so that the speed of the motor is reduced, thereby reducing the temperature of the DC side of the inverter circuit of the controller, and avoiding the high temperature on the battery and the components in the circuit, so as to better protect the battery and the circuit components. In addition, by adjusting the maximum output value of the speed loop controller instead of directly limiting the operation of the motor, it can be ensured that the power of the motor will not be low, thereby protecting the components and the battery while ensuring that the operation of the motor will not be slow, thereby ensuring the operation of the vehicle.

[0041] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 is a flow chart of a vehicle control method provided by an embodiment of the present invention;

[0044] Figure 2 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0045] Figure 3 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0046] Figure 4 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0047] Figure 5 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0048] Figure 6 It is a structural schematic diagram of a vehicle control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] An embodiment of the present invention provides a method for controlling a vehicle, wherein the vehicle includes a motor, a battery, and a controller; the controller is connected between the battery and the motor, and is used to convert the power output by the battery. The vehicle may be an electric vehicle, such as an electric industrial vehicle, or a non-industrial vehicle. The controller includes an inverter circuit, which can convert the power output by the battery, such as converting direct current into alternating current, so as to drive the motor to operate. The method for controlling the vehicle is executed by the controller.

[0052] Figure 1is a flow chart of a vehicle control method provided by an embodiment of the present invention, with reference to Figure 1 , the vehicle control method includes:

[0053] S110: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, starting a current limiting regulation strategy.

[0054] The output current of the battery is also the input current of the inverter circuit in the controller, and the output current of the battery is the current collected in real time. The output current of the battery can be collected according to the Hall sensor or the current sensor. The maximum current of the battery can be the maximum current that the battery can output or the maximum current that the inverter circuit in the controller can access.

[0055] Specifically, when the output current of the battery is greater than the maximum current of the battery, the timing starts, and each time the output current is greater than the maximum current of the battery, the controller continues timing. After the timing starts, if the output current is less than or equal to the maximum current of the battery, the timing duration is reduced. Until the timing duration reaches the first preset duration, it indicates that the output current of the battery is indeed large and greater than the maximum current of the battery, then it is determined that the temperature of the DC side of the inverter circuit in the controller is high, and the current limiting regulation strategy is started. In this way, it can be avoided that the current limiting regulation strategy is started when the output current of the battery is instantaneously large, and the accuracy of the control can be guaranteed.

[0056] S120, cyclically executing the steps of determining the target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy, until the duration of starting the current limiting adjustment strategy reaches a second preset duration.

[0057] Among them, the current limiting regulation strategy may include a proportional integral control strategy or a proportional integral differential control strategy. The speed loop control strategy may include a proportional integral control strategy or a proportional integral differential control strategy. The speed loop control strategy may determine the target current according to the target speed and the actual speed of the motor, or transform the output value of the speed loop control strategy (for example, perform a limiting process) to obtain the target current. The current loop control strategy may determine the target voltage of the motor according to the target current and the actual current of the motor, and control the motor operation according to the target voltage, thereby controlling the speed of the motor.

[0058] Specifically, the target adjustment amount can be determined according to the current limiting adjustment strategy, and the target adjustment amount can adjust the maximum output value of the speed loop control strategy so that the output value of the speed loop control strategy is less than or equal to the adjusted maximum output value, which can reduce the output value of the speed loop control strategy, that is, reduce the target current, thereby reducing the target voltage output by the current loop control strategy, so that the speed of the motor is reduced. There is a corresponding relationship between the power of the battery and the power of the motor, that is, the output voltage U of the battery and the output current I d The product of U×I corresponds to the product of the motor torque T and speed V. For example, dc =T×V×N, where N is a constant. Therefore, by adjusting the maximum output value of the speed loop control strategy, the output current I of the battery can be reduced after the motor speed is reduced. dc , thereby reducing the temperature of the DC side of the controller's inverter circuit, which can avoid the high temperature on the battery and components in the circuit (such as energy storage capacitors, filter capacitors, fuses and contactors, etc.), thereby better protecting the battery and circuit components.

[0059] In addition, by adjusting the maximum output value of the speed loop controller instead of directly limiting the motor operation, it can be ensured that the motor power will not be too low, thereby protecting components and batteries while ensuring that the motor will not run too slowly, thereby ensuring the operation of the vehicle.

[0060] After determining the target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy, the output current of the battery changes, and then based on the output current of the battery, determining the target adjustment amount according to the current limiting adjustment strategy, and adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy, the cycle is repeated until the start of the current limiting strategy reaches a second preset time, so that the temperature of the DC side of the inverter circuit of the controller is reduced to a safe temperature, and the current limiting adjustment strategy can be exited, that is, the adjustment of the maximum output value of the speed loop control strategy of the motor is stopped, then the maximum output value remains unchanged, and the operation of the motor continues to be controlled according to the speed loop control strategy and the current loop control strategy until the next time the output current of the battery is greater than the maximum current of the battery for a time that reaches the first preset time, and then the current limiting adjustment strategy is started again.

[0061] The technical solution of this embodiment is to start the current limiting regulation strategy when the duration of the battery output current greater than the maximum current of the battery reaches a first preset duration, and to cyclically execute the steps of determining the target adjustment amount according to the current limiting regulation strategy, adjusting the maximum output value of the motor's speed loop control strategy according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the motor's speed according to the target current and the current loop control strategy, until the duration of starting the current limiting regulation strategy reaches a second preset duration. The output value of the speed loop control strategy can be reduced, that is, the target current is reduced, thereby reducing the target voltage output by the current loop control strategy, so that the motor's speed is reduced, thereby reducing the temperature of the DC side of the controller's inverter circuit, and avoiding the high temperature on the battery and the components in the circuit, so as to better protect the battery and the circuit components. In addition, by adjusting the maximum output value of the speed loop controller instead of directly limiting the motor operation, it can be ensured that the power of the motor will not be low, thereby protecting the components and the battery while ensuring that the motor will not run slowly, thereby ensuring the operation of the vehicle.

[0062] On the basis of the above technical solution, the method of determining the target adjustment amount according to the current limiting adjustment strategy is described below, but it is not intended to limit the present application.

[0063] Figure 2 is a flowchart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 2 , the vehicle control method includes:

[0064] S210: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, starting a current limiting regulation strategy.

[0065] S220, determining whether the startup duration of the current limiting regulation strategy reaches a second preset duration, if so, executing step S291; if not, executing step S230.

[0066] Specifically, the value of the second preset duration can be obtained according to the test. If the startup duration of the current limiting regulation strategy reaches the second preset duration, the current limiting time is longer, and the temperature of the DC side of the inverter circuit of the controller can reach a safe temperature. If the startup duration of the current limiting regulation strategy does not reach the second preset duration, the current limiting regulation continues.

[0067] S230, determining whether the output current of the battery is greater than a preset current, if not, executing step S240; if yes, executing step S250.

[0068] Specifically, the preset current is a DC current that can maintain the long-term operation of the controller, that is, a DC current that can ensure that the controller can work for a long time and the temperature does not exceed the temperature threshold. According to the relationship between the preset current and the output current of the battery, the target adjustment amount is determined, and the output current of the battery can be adjusted to near the preset current to ensure that the temperature of the DC side of the controller is low.

[0069] S240: Determine the target adjustment amount as the maximum adjustment amount.

[0070] Specifically, if the output current of the battery is less than or equal to the preset current, the output current of the battery is small, which can meet the long-term operation of the controller and the temperature will not exceed the temperature threshold. Then the target adjustment amount can be large, that is, the maximum adjustment amount, so as to ensure that the maximum output value of the speed loop control strategy is large, and the power of the motor is large, so that the vehicle will not be too slow and the operation of the vehicle is guaranteed.

[0071] S250: Determine an initial adjustment amount according to the output current and the preset current and based on a proportional-integral control strategy.

[0072] Specifically, the preset current is used as the target, and the preset current and the current output current are substituted into the proportional integral control strategy to obtain the initial adjustment amount, so that after the maximum output value of the speed loop control strategy is adjusted according to the initial adjustment amount, the current on the DC side of the controller (i.e., the output current of the battery) can be close to the preset current. In this way, the current on the DC side of the controller can be reduced to ensure that the temperature of the DC side of the controller is low.

[0073] S260, determine whether the initial adjustment amount is greater than the minimum adjustment amount, if so, execute step S270; if not, execute step S280.

[0074] Specifically, if the minimum adjustment amount is a negative value, for example, it can ensure that the maximum output value of the speed loop control strategy is reduced, thereby reducing the speed of the motor, and then reducing the current on the DC side of the controller (i.e., the output current of the battery), thereby ensuring that the temperature of the DC side of the controller is low. By using the minimum adjustment amount as the limit value and determining the target adjustment amount, it is possible to avoid excessive adjustment of the maximum output value of the speed loop control strategy, that is, to avoid excessive reduction in the motor speed, thereby ensuring that the vehicle will not be too slow and avoid affecting the operation of the vehicle.

[0075] S270: Determine the initial adjustment amount as the target adjustment amount.

[0076] Specifically, when the initial adjustment amount is greater than the minimum adjustment amount, it indicates that the absolute value of the initial adjustment amount is small and has not reached the limit value. Then, the initial adjustment amount can be used as the target adjustment amount, so that after adjusting the maximum output value of the speed loop control strategy according to the initial adjustment amount, the maximum output value of the speed loop control strategy can be larger, and the motor speed can be larger, thereby making the motor power larger. In this way, the operation of the vehicle is guaranteed on the basis of protecting the circuit and components.

[0077] S280: Determine the minimum adjustment amount as the target adjustment amount.

[0078] Specifically, when the initial adjustment amount is less than or equal to the minimum adjustment amount, it indicates that the absolute value of the initial adjustment amount is large. Then, the minimum adjustment amount is used as the target adjustment amount, which can avoid the maximum output value of the speed loop control strategy from decreasing too much, thereby ensuring the operation of the motor and thus the operation of the vehicle.

[0079] S290, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining the target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy; and returning to execute step S220.

[0080] Specifically, the maximum output value of the speed loop control strategy of the motor is adjusted according to the target adjustment amount, that is, the target adjustment amount is added to the maximum output value of the speed loop control strategy of the motor to obtain the adjusted maximum output value.

[0081] Exemplarily, the target adjustment amount is I out The maximum output value of the motor's speed loop control strategy is V out_max , the maximum output value after adjustment is V out_max +I out .

[0082] S291. Stop adjusting the maximum output value of the speed loop control strategy.

[0083] Specifically, stop adjusting the maximum output value of the speed loop control strategy, that is, exit the current limiting adjustment strategy, keep the maximum output value of the speed loop control strategy unchanged, and continue to control the motor according to the speed loop control strategy and the current loop control strategy.

[0084] Based on the above technical solution, optionally, the maximum adjustment amount is zero and the minimum adjustment amount is a negative value.

[0085] Specifically, by setting the maximum adjustment amount to zero, the output current of the battery can be less than or equal to the preset current, that is, the output current of the battery is small, which can meet the long-term operation of the controller and the temperature will not exceed the temperature threshold. The maximum output value of the speed loop control strategy is not adjusted to ensure the operation of the motor, and then the operation of the vehicle. That is, it will not be adjusted in the direction of increasing the maximum output value of the speed loop control strategy, avoiding increasing the motor speed and thus increasing the temperature of the controller.

[0086] By setting the minimum adjustment amount to a negative value, when the output current of the battery is greater than the preset current, the maximum output value of the speed loop control strategy can be reduced, thereby reducing the target current output by the speed loop control strategy, and then reducing the target voltage output by the current loop control strategy, thereby reducing the speed of the motor, and then reducing the DC side current of the controller (that is, the output current of the battery), thereby reducing the DC side temperature of the controller and achieving temperature protection for the vehicle.

[0087] Optionally, the minimum adjustment amount is the negative of the maximum output value of the speed loop control strategy before starting the current limiting adjustment strategy. In this way, the maximum output value of the speed loop control strategy can be adjusted to zero at most, avoiding adjusting the maximum output value of the speed loop control strategy to a negative number, thereby changing the operation method of the motor.

[0088] On the basis of the above technical solution, optionally, the initial adjustment amount is determined according to the output current and based on a proportional-integral control strategy, including:

[0089] Step a1: multiply the difference between the preset current and the current output current of the battery by a first proportional coefficient to obtain a first proportional term.

[0090] Specifically, the deviation between the current output current and the preset current can be determined based on the difference between the preset current and the current output current of the battery, and the initial adjustment amount can be determined based on the deviation, so that after the maximum output value of the speed loop control strategy is adjusted according to the initial adjustment amount, the current on the DC side of the controller (i.e., the output current) is close to the preset current.

[0091] Exemplarily, the preset current is I ref , the current output current of the battery is I fab , the first proportionality coefficient is K P1 , the first proportional term is I P1 , then the first proportional term is I P1 =K P1 ×(I ref -I fab ). Because the output current is greater than the preset current, the first proportional term I P1 Less than zero.

[0092] Step a2: Add the product of the first proportional term and the first integral coefficient to the previous first integral term to obtain the current first integral term.

[0093] Specifically, the previous first integral term is the first integral term when the current limiting regulation strategy was performed last time. By determining the current first integral term, it is convenient to determine the accumulation of the current output current and the preset current deviation, so as to accurately determine the initial regulation amount.

[0094] Exemplarily, the first integral coefficient is K i1 , the previous first integral term is I i-1 , the current first integral term is I i , then the current first integral term is I i =I i-1 +K i1 ×I P1 Because the first proportional term is less than zero, the first integral term is less than zero. When there is no first integral term before the current first integral term, the previous first integral term may be zero, which is not limited in this embodiment.

[0095] Step a3: Add the first proportional term to the current first integral term to obtain an initial adjustment amount.

[0096] Exemplarily, the first proportional term is I P1 , the first integral term is I i , the initial adjustment amount is I out1 , then the initial adjustment amount is I oit1 =I P1 +I i . Because the first proportional term is less than zero and the first integral term is less than zero, the initial adjustment amount is less than zero. In this way, the maximum output value of the speed loop adjustment strategy can be reduced, and then the output value of the speed loop control strategy can be reduced, that is, the target current is reduced, thereby reducing the target voltage output by the current loop control strategy, so that the speed of the motor is reduced, thereby reducing the temperature of the DC side of the controller's inverter circuit, which can avoid the high temperature on the battery and components in the circuit, thereby better protecting the battery and circuit components.

[0097] On the basis of the above technical solutions, Figure 3 is a flowchart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 3 , the vehicle control method includes:

[0098] S310: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, start a current limiting regulation strategy.

[0099] S320, start timing when starting the current limiting regulation strategy.

[0100] Specifically, when the current limiting regulation strategy is started, a timer may be started, which may be started from zero or counted down from a second preset duration, which is not limited in this embodiment. In this way, the duration of starting the current limiting regulation strategy may be determined, so that the duration of starting the current limiting regulation strategy reaches the second preset duration, thereby causing the temperature of the controller to reach a safe temperature.

[0101] S330, cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the motor's speed loop control strategy according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the motor's speed according to the target current and the current loop control strategy.

[0102] S340: When the timing duration reaches a second preset duration and the vehicle stops running, stop adjusting the maximum output value of the speed loop control strategy.

[0103] Specifically, when the timing reaches the second preset time, it indicates that the temperature of the controller has reached a safe temperature. When the timing reaches the second preset time and the vehicle stops running, the current limiting is released, that is, the maximum output value of the speed loop control strategy is stopped to be adjusted, which can avoid the sudden release of the current limiting, causing a sudden change in the speed of the whole vehicle, and bringing safety hazards to the driver. In this way, the reliability and safety of vehicle control are improved.

[0104] On the basis of the above technical solutions, optionally, the vehicle control method further includes:

[0105] When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, an alarm signal is issued.

[0106] Specifically, when the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, that is, when the current limiting regulation strategy is started, an alarm signal is issued to prompt the driver, so that the driver is informed that the controller temperature is high and the vehicle starts the current limiting regulation strategy.

[0107] On the basis of the above technical solutions, Figure 4 is a flowchart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 4 , the vehicle control method includes:

[0108] S410: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, start a current limiting regulation strategy.

[0109] S420, start timing when starting the current limiting regulation strategy.

[0110] S430, cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the motor's speed loop control strategy according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the motor's speed according to the target current and the current loop control strategy.

[0111] S440: If the vehicle is restarted before the timing duration reaches the second preset duration, the timing continues and the current limiting adjustment strategy continues to be executed after the vehicle is restarted, and when the timing duration reaches the second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted.

[0112] Specifically, when the driver receives a signal that the vehicle is being limited or receives an alarm signal, the vehicle may be restarted, resulting in a timing interruption. When the controller receives a restart signal, the current timing duration can be saved. After the vehicle is restarted, the timing continues, that is, the current limiting adjustment strategy continues to be executed until the timing duration reaches the second preset duration, and when the vehicle stops running, the current limiting is released, that is, the maximum output value of the speed loop control strategy is stopped from being adjusted. In this way, the temperature of the controller can be guaranteed to be lowered, achieving a better effect of protecting the components and circuits.

[0113] On the basis of the above technical solutions, Figure 5 is a flowchart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 5 , the vehicle control method includes:

[0114] S510: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, start a current limiting regulation strategy.

[0115] S520: Start timing when starting the current limiting regulation strategy.

[0116] S530, cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy.

[0117] S540. If the vehicle is turned off before the timing duration reaches the second preset duration, determine whether the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on is greater than the preset difference. If not, execute step S550; if so, execute step S560.

[0118] The historical temperature is the temperature of the controller when the current limiting regulation strategy is started.

[0119] Specifically, if the vehicle is shut down before the timing duration reaches the second preset duration, then after the vehicle is restarted, the actual temperature of the controller is obtained, and the actual temperature of the controller is compared with the historical temperature. Based on the difference between the actual temperature of the controller and the historical temperature, it is determined whether to continue the current limiting regulation strategy.

[0120] S550, continue timing and continue executing the current limiting adjustment strategy, and when the timing duration reaches a second preset duration and the vehicle stops running, stop adjusting the maximum output value of the speed loop control strategy.

[0121] Among them, the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on can be the difference between the historical temperature and the actual temperature, or it can be the ratio of the historical temperature to the actual temperature, which is not limited here.

[0122] Specifically, when the difference between the actual temperature of the controller after the vehicle is powered on and the historical temperature is less than or equal to the preset difference, it indicates that the difference between the actual temperature of the controller after the vehicle is powered on and the historical temperature is small, and the temperature of the vehicle controller is still high, then the timing continues, that is, the current limiting adjustment strategy continues to be executed. When the timing duration reaches the second preset duration and the vehicle stops running, the current limiting adjustment strategy is exited, that is, the maximum output value of the speed loop control strategy is stopped from being adjusted.

[0123] S560: Stop adjusting the maximum output value of the speed loop control strategy.

[0124] On the basis of the above technical solutions, optionally, the target current is determined according to the adjusted maximum output value and the speed loop control strategy, and the speed of the motor is controlled according to the target current and the current loop control strategy, including:

[0125] Step b1: taking the adjusted maximum output value as the limit value, and determining the target current according to the speed loop proportional integral control strategy.

[0126] Specifically, the speed loop control strategy includes a speed loop proportional integral control strategy. The actual speed of the motor and the target speed of the motor are substituted into the speed loop proportional integral control strategy to obtain an output value. When the output value of the speed loop proportional integral control strategy is greater than the maximum output value after adjustment, the maximum output value after adjustment is used as the limit value. When the output value of the speed loop proportional integral control strategy is less than or equal to the maximum output value after adjustment, the output value of the speed loop proportional integral control strategy is used as the target current. In this way, the target current will not exceed the maximum output value after adjustment, and the motor speed can be reduced, thereby reducing the current on the DC side of the controller, and then reducing the temperature on the DC side of the controller.

[0127] Step b2: determine the target voltage of the motor according to the target current and the current loop proportional-integral control strategy, and drive the motor to operate according to the target voltage to control the speed of the motor.

[0128] Specifically, the current loop control strategy includes a current loop proportional-integral control strategy. The target current and the actual current of the motor are substituted into the current loop proportional-integral control strategy to obtain the target voltage. Since the target current decreases, the target voltage decreases. After the motor is driven to run according to the target voltage, the speed of the motor decreases, thereby reducing the current on the DC side of the controller, thereby reducing the temperature on the DC side of the controller.

[0129] On the basis of the above technical solution, optionally, the adjusted maximum output value is used as a limit value, and the target current is determined according to the speed loop proportional integral control strategy, including:

[0130] Step c1, multiply the difference between the actual speed of the motor and the target speed by the second proportional coefficient to obtain the second proportional term, and add the product of the second proportional term and the second integral coefficient to the previous second integral term to obtain the current second integral term, and use the sum of the second proportional term and the current second integral term as the initial current.

[0131] For example, the actual speed of the motor is V fab , the target speed of the motor is V ref , the second proportionality coefficient is K P2 , the second proportional term is V P , then V P =K P2 ×(V ref -V fab ). The second integral coefficient is K i2 , the second integral term before is V i-1 , the current second integral term is V i , then V i =V i-1 +K i2 ×V P The initial current is V out , then V out =V i +V P Wherein, when there is no second integral item before the current second integral item, the previous second integral item may be zero, which is not limited in this embodiment.

[0132] Step c2: when the initial current is less than the adjusted maximum output value, the initial current is used as the target current; when the initial current is greater than or equal to the adjusted maximum output value, the adjusted maximum output value is used as the target current.

[0133] Specifically, the adjusted maximum output value is the limit value. When the initial current is less than the adjusted maximum output value, the initial current is used as the target current; when the initial current is greater than or equal to the adjusted maximum output value, the adjusted maximum output value is used as the target current, thereby reducing the output target current, thereby reducing the output value of the current loop control strategy, and thereby reducing the speed of the motor.

[0134] Optionally, determining a target voltage of the motor according to the target current and a current loop proportional-integral control strategy, and driving the motor to operate according to the target voltage includes:

[0135] Multiply the difference between the actual current and the target current of the motor by the third proportional coefficient to obtain the third proportional term, and add the product of the third proportional term and the third integral coefficient to the previous third integral term to obtain the current third integral term, and use the sum of the third proportional term and the current third integral term as the target voltage to drive the motor to operate.

[0136] For example, the target current of the motor is I d_ref , the actual current of the motor is I d+fab , the third proportional coefficient is K P3 , the third proportional term is I d_P , then I d_P =K P3 ×(I d_ref -I d_fab ). The third integral coefficient is K i3 , the previous second integral term is I d_i-1 , the current second integral term is I di , then I d_i =I d_i-1 +K i3 ×I d_P The target voltage is I d_out , then I d_out =I d_P +I d_i . Wherein, when there is no third integral term before the current third integral term, the previous third integral term may be zero, which is not limited in this embodiment. In this way, the motor is driven to operate according to the target voltage, the motor speed can be reduced, and then the current on the DC side of the controller is reduced, thereby reducing the temperature on the DC side of the controller, and better protecting the circuits and components.

[0137] The embodiment of the present invention further provides a vehicle control system, Figure 6 is a schematic diagram of a vehicle control system provided by an embodiment of the present invention, with reference to Figure 6The vehicle control system includes: a motor 101, a battery 102 and a controller 103; the controller 103 is connected between the battery 102 and the motor 101, and is used to convert the power output by the battery 102; the controller 103 is used to execute the vehicle control method provided by any embodiment of the present invention. Therefore, the vehicle control system provided in this embodiment has the same beneficial effects as the vehicle control method provided by any embodiment of the present invention, and will not be described in detail here.

[0138] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0139] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vehicle control method, characterized in that: The vehicle comprises a motor, a battery and a controller; the controller is connected between the battery and the motor, and is used to convert the power output by the battery; The vehicle control method is executed by the controller; The vehicle control method comprises: When the duration during which the output current of the battery is greater than the maximum current of the battery reaches a first preset duration, starting a current limiting regulation strategy; The steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration.

2. The method according to claim 1, characterized in that The determining of the target adjustment amount according to the current limiting adjustment strategy includes: If the output current of the battery is less than or equal to the preset current, the target adjustment amount is determined to be the maximum adjustment amount; if the output current is greater than the preset current, the initial adjustment amount is determined according to the output current and the preset current and based on a proportional-integral control strategy; If the initial adjustment amount is greater than the minimum adjustment amount, the initial adjustment amount is determined to be the target adjustment amount; if the initial adjustment amount is less than or equal to the minimum adjustment amount, the minimum adjustment amount is determined to be the target adjustment amount.

3. The method according to claim 2, characterized in that The maximum adjustment amount is zero, and the minimum adjustment amount is a negative value.

4. The method according to claim 2, characterized in that: The determining the initial adjustment amount according to the output current and based on a proportional-integral control strategy includes: Multiplying the difference between the preset current and the current output current of the battery by a first proportional coefficient to obtain a first proportional term; The product of the first proportional term and the first integral coefficient is added to the previous first integral term to obtain a current first integral term; The first proportional term is added to the current first integral term to obtain the initial adjustment amount.

5. The method according to claim 1, characterized in that The steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including: The timing starts when the current limiting regulation strategy is started; The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy; When the timing duration reaches a second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted.

6. The method according to claim 1, characterized in that The steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including: The timing starts when the current limiting regulation strategy is started; The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy; If the vehicle is restarted before the timing duration reaches the second preset duration, the timing continues and the current limiting adjustment strategy continues to be executed after the vehicle is restarted, and when the timing duration reaches the second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted.

7. The method according to claim 1, characterized in that The steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy are cyclically executed until the duration of starting the current limiting adjustment strategy reaches a second preset duration, including: The timing starts when the current limiting regulation strategy is started; The steps of cyclically executing the steps of determining a target adjustment amount according to the current limiting adjustment strategy, adjusting the maximum output value of the speed loop control strategy of the motor according to the target adjustment amount, determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy; If the vehicle is turned off before the timing duration reaches the second preset duration, then when the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on is less than or equal to the preset difference, the timing continues and the current limiting regulation strategy continues to be executed, and when the timing duration reaches the second preset duration and the vehicle stops running, the maximum output value of the speed loop control strategy is stopped from being adjusted; wherein the historical temperature is the temperature of the controller when the current limiting regulation strategy is started; When the difference between the actual temperature of the controller and the historical temperature after the vehicle is powered on is greater than the preset difference, the maximum output value of the speed loop control strategy is stopped from being adjusted.

8. The method according to any one of claims 1 to 7, characterized in that: Determining a target current according to the adjusted maximum output value and the speed loop control strategy, and controlling the speed of the motor according to the target current and the current loop control strategy, including: The adjusted maximum output value is used as a limit value, and the target current is determined according to a speed loop proportional-integral control strategy; The target voltage of the motor is determined according to the target current and the current loop proportional-integral control strategy, and the motor is driven to operate according to the target voltage to control the rotation speed of the motor.

9. The method according to claim 8, characterized in that The adjusted maximum output value is used as a limit value, and the target current is determined according to a speed loop proportional integral control strategy, including: The difference between the actual speed of the motor and the target speed is multiplied by the second proportional coefficient to obtain a second proportional term, and the product of the second proportional term and the second integral coefficient is added to the previous second integral term to obtain a current second integral term, and the sum of the second proportional term and the current second integral term is used as the initial current; When the initial current is less than the adjusted maximum output value, the initial current is used as the target current; when the initial current is greater than or equal to the adjusted maximum output value, the adjusted maximum output value is used as the target current; Determining a target voltage of the motor according to the target current and a current loop proportional-integral control strategy, and driving the motor to operate according to the target voltage, including: The difference between the actual current of the motor and the target current is multiplied by the third proportional coefficient to obtain a third proportional term, and the product of the third proportional term and the third integral coefficient is added to the previous third integral term to obtain a current third integral term, and the sum of the third proportional term and the current third integral term is used as the target voltage to drive the motor to operate.

10. A vehicle control system, characterized in that: include: Motors, batteries and controllers; The controller is connected between the battery and the motor, and is used to convert the power output by the battery; The controller is used to execute the vehicle control method described in any one of claims 1-9.

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