Vehicle brake control method, brake control device, and vehicle controller

Abstract

The invention discloses a vehicle braking control method, a braking control device and a vehicle controller. Belongs to the technical field of vehicles. Whether the current vehicle speed is larger than a first preset vehicle speed or not is judged, if the current vehicle speed is larger than the first preset vehicle speed, direct current is supplied to the induction motor for braking, and if the current vehicle speed is smaller than or equal to the first preset vehicle speed, reverse alternating current is supplied to the induction motor for braking; the braking stability and controllability of the vehicle at a high speed can be guaranteed, when reverse alternating current is connected to the induction motor for reverse connection braking, reliable braking force can be rapidly generated when the vehicle is at a low speed, and braking of the vehicle is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and more particularly, to a braking control method for a vehicle, a braking control device, and a vehicle controller. Background Art

[0002] In related technologies, the mechanical braking system of a traditional vehicle includes a hydraulic braking system. The hydraulic braking system includes brake discs and brake calipers that match four wheels, as well as corresponding oil circuits, hydraulic pumps, and other structures. The weight of the hydraulic braking system is relatively large, which is not conducive to the lightweight of the vehicle. At the same time, when the hydraulic braking system fails, the vehicle cannot effectively decelerate, affecting the safety of the vehicle. Summary of the Invention

[0003] The present invention aims to solve at least one of the above technical problems in the prior art to some extent. For this purpose, the present invention provides a braking control method for a vehicle, which can use an induction motor to perform stable and reliable braking to improve the safety of the vehicle.

[0004] The present invention also provides a computer-readable storage medium.

[0005] The present invention also provides a vehicle controller.

[0006] The present invention also provides a braking control device for a vehicle.

[0007] According to the braking control method for a vehicle according to the first aspect embodiment of the present invention, the vehicle includes: an induction motor and a wheel, and the induction motor is in transmission connection with the wheel. The braking control method for the vehicle includes: receiving a braking signal; determining whether the current vehicle speed is greater than a first preset vehicle speed; if the current vehicle speed is greater than the first preset vehicle speed, then applying direct current to the induction motor for braking; if the current vehicle speed is less than or equal to the first preset vehicle speed, then applying reverse alternating current to the induction motor for braking.

[0008] According to the braking control method for a vehicle according to the embodiment of the present invention, when the vehicle brakes, if the vehicle speed is greater than the first preset vehicle speed, then applying direct current to the induction motor for energy consumption braking to ensure the stability and controllability of the vehicle during high-speed braking. If the vehicle speed is less than or equal to the first preset vehicle speed, then applying reverse alternating current to the induction motor for reverse connection braking to quickly generate reliable braking force when the vehicle is at a low speed and ensure that the vehicle stops.

[0009] According to some embodiments of the present invention, the first preset vehicle speed is V1, and satisfies the relational expression 5 km / h ≤ V1 ≤ 20 km / h.

[0010] According to some embodiments of the present invention, braking is performed by applying direct current to the induction motor, including: obtaining the opening value of the brake pedal according to the braking signal, and controlling the current value of the direct current applied to the induction motor to be positively correlated with the opening value of the brake pedal; braking is performed by applying reverse alternating current to the induction motor, including: obtaining the opening value of the brake pedal according to the braking signal, and controlling the current value of the reverse alternating current applied to the induction motor to be positively correlated with the opening value of the brake pedal.

[0011] According to some embodiments of the present invention, the vehicle further includes: a permanent magnet motor and an energy consumption component. The permanent magnet motor is in transmission connection with the wheel, and the permanent magnet motor is selectively electrically connected to the energy consumption component. After receiving the braking signal, the braking control method of the vehicle further includes: disconnecting the power supply of the permanent magnet motor and controlling the energy consumption component to be electrically connected to the permanent magnet motor.

[0012] According to some embodiments of the present invention, the energy consumption component includes: a first energy consumption resistor and a first switch. The first energy consumption resistor is selectively electrically connected to the first phase interface of the permanent magnet motor through the first switch; a second energy consumption resistor and a second switch. The second energy consumption resistor is selectively electrically connected to the second phase interface of the permanent magnet motor through the second switch; a third energy consumption resistor and a third switch. The third energy consumption resistor is selectively electrically connected to the third phase interface of the permanent magnet motor through the third switch.

[0013] According to some embodiments of the present invention, controlling the energy consumption component to be electrically connected to the permanent magnet motor includes: obtaining the opening value of the brake pedal according to the braking signal, and controlling the duty ratios of the first switch, the second switch, and the third switch to be positively correlated with the opening value of the brake pedal.

[0014] According to some embodiments of the present invention, the vehicle further includes a mechanical braking system. The braking control method of the vehicle further includes: determining whether the current vehicle speed is less than or equal to a second preset vehicle speed; if the previous vehicle speed is less than or equal to the second preset vehicle speed, then controlling the mechanical braking system to brake the wheel; wherein, the second preset vehicle speed is less than the first preset vehicle speed.

[0015] According to a computer-readable storage medium of the second aspect embodiment of the present invention, a braking control program of a vehicle is stored thereon. When the braking control program of the vehicle is executed by a processor, the above-mentioned braking control method of the vehicle is implemented.

[0016] According to the computer-readable storage medium of an embodiment of the present invention, by means of the above-mentioned braking control method for a vehicle, when the vehicle is braking, if the vehicle speed is greater than a first preset speed, direct current is applied to the induction motor for energy consumption braking to ensure the stability and controllability of the vehicle during high-speed braking. If the vehicle speed is less than or equal to the first preset speed, reverse alternating current is applied to the induction motor for plugging braking to quickly generate reliable braking force when the vehicle is at a low speed and ensure that the vehicle stops.

[0017] The vehicle controller according to the third aspect embodiment of the present invention includes a memory, a processor, and a braking control program for the vehicle stored on the memory and executable on the processor. When the processor executes the braking control program for the vehicle, the above-mentioned braking control method for the vehicle is implemented.

[0018] According to the vehicle controller of an embodiment of the present invention, by means of the above-mentioned braking control method for a vehicle, when the vehicle is braking, if the vehicle speed is greater than a first preset speed, direct current is applied to the induction motor for energy consumption braking to ensure the stability and controllability of the vehicle during high-speed braking. If the vehicle speed is less than or equal to the first preset speed, reverse alternating current is applied to the induction motor for plugging braking to quickly generate reliable braking force when the vehicle is at a low speed and ensure that the vehicle stops.

[0019] According to the braking control device for a vehicle of the fourth aspect embodiment of the present invention, the vehicle includes an induction motor and a wheel, and the induction motor is in transmission connection with the wheel. The braking control device for the vehicle includes a receiving module for receiving a braking signal, and a control module for determining whether the current vehicle speed is greater than a first preset speed. If the current vehicle speed is greater than the first preset speed, direct current is applied to the induction motor for braking. If the current vehicle speed is less than or equal to the first preset speed, reverse alternating current is applied to the induction motor for braking.

[0020] According to the braking control device for a vehicle of an embodiment of the present invention, when the vehicle is braking, if the vehicle speed is greater than a first preset speed, the control module can control direct current to be applied to the induction motor for energy consumption braking to ensure the stability and controllability of the vehicle during high-speed braking. If the vehicle speed is less than or equal to the first preset speed, the control module can control reverse alternating current to be applied to the induction motor for plugging braking to quickly generate reliable braking force when the vehicle is at a low speed and ensure that the vehicle stops.

[0021] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Brief Description of the Drawings

[0022] Figure 1It is a flowchart of a braking control method for a vehicle according to an embodiment of the present invention;

[0023] Figure 2 It is a schematic diagram of an induction motor, a motor controller, a power source, and a wheel according to an embodiment of the present invention;

[0024] Figure 3 It is a schematic diagram of a permanent magnet motor, a motor controller, an energy consumption component, a power source, and a wheel according to an embodiment of the present invention;

[0025] Figure 4 It is a flowchart of a braking control method for a vehicle according to another embodiment of the present invention.

[0026] Reference numerals:

[0027] Induction motor 1;

[0028] Wheel 2;

[0029] Permanent magnet motor 3;

[0030] Energy consumption component 4; First switch 41; Second switch 42; Third switch 43; First energy consumption resistor 44; Second energy consumption resistor 45; Third energy consumption resistor 46;

[0031] Power source 5;

[0032] Motor controller 6. Detailed implementation manners

[0033] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0034] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0035] In the present invention, unless otherwise clearly specified or limited, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral body; it may be a mechanical connection, an electrical connection, or a connection that enables mutual communication; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] The following will describe in detail a braking control method, a braking control device, and a vehicle controller of a vehicle according to an embodiment of the present invention with reference to the accompanying drawings.

[0037] A braking control method of a vehicle according to an embodiment of the first aspect of the present invention, the vehicle including: an induction motor and a wheel, the induction motor being in transmission connection with the wheel, the induction motor being capable of driving the wheel to rotate so that the vehicle travels, and the induction motor being further capable of applying a braking torque to the wheel so that the vehicle decelerates and brakes.

[0038] Referring to Figure 1 As shown, the braking control method of the vehicle includes:

[0039] Step S1, receiving a braking signal.

[0040] Wherein, when the driver steps on the brake pedal, a sensor for detecting the opening of the brake pedal in the vehicle can generate a corresponding braking signal and send it to the control module of the vehicle, so that the control module receives the braking signal.

[0041] Step S2, determining whether the current vehicle speed is greater than a first preset vehicle speed.

[0042] Wherein, the control module can obtain the current vehicle speed of the vehicle through a wheel speed sensor of the vehicle and determine whether the current vehicle speed is greater than the first preset vehicle speed.

[0043] Step S3, if the current vehicle speed is greater than the first preset vehicle speed, then pass direct current into the induction motor for braking.

[0044] Wherein, when the control module determines that the current vehicle speed is greater than the first preset vehicle speed, the vehicle speed and the rotor speed of the induction motor are relatively fast. At this time, the control module can control the motor controller to cause the motor controller to pass direct current into the induction motor. In the interfaces of the three-phase electricity of the induction motor, the direct current can enter in single-phase and exit in two-phase, or enter in two-phase and exit in single-phase, or enter and exit in single-phase, so that the induction motor enters the energy consumption braking state. The induction motor can consume direct current to brake the wheel. The braking torque of this braking method decreases as the speed decreases, and the braking process is relatively stable.

[0045] It can be understood that when the vehicle is running normally, three-phase alternating current is applied to the stator winding of the induction motor to generate a rotating magnetic field. The rotor of the induction motor cuts the rotating magnetic field to generate an induced current to form a driving torque to drive the wheels to rotate. When the vehicle brakes, when the three-phase alternating current is disconnected from the induction motor and direct current is applied, the direct current can make the stator magnetic field of the induction motor stationary. The rotor of the induction motor cuts the magnetic field to generate a reverse eddy current braking torque to convert mechanical energy into heat energy and consume it. At the same time, the braking torque decreases as the speed decreases, thereby achieving smooth braking without mechanical wear.

[0046] Step S4, if the current vehicle speed is less than or equal to the first preset vehicle speed, reverse alternating current is applied to the induction motor for braking.

[0047] Among them, when the control module determines that the current vehicle speed is less than or equal to the first preset vehicle speed, the vehicle speed and the rotor speed of the induction motor are relatively slow. At this time, the control module can control the motor controller to make the motor controller apply reverse alternating current to the induction motor, that is, exchange any two of the three phases in the power supply to the induction motor. For example, exchange phase U and phase V to change the power supply phase sequence of the stator winding of the induction motor, so that the direction of the rotating magnetic field is reversed, thereby generating an electromagnetic torque opposite to the rotor rotation direction, so that the induction motor enters the plugging braking state and realizes rapid braking.

[0048] It can be understood that when the vehicle is running normally, three-phase alternating current is applied to the stator winding of the induction motor to generate a rotating magnetic field. The rotor of the induction motor cuts the rotating magnetic field to generate an induced current to form a driving torque to drive the wheels to rotate. When the vehicle brakes, exchange any two of the three-phase power supplies of the stator to reverse the direction of the stator rotating magnetic field. The rotating direction of the stator magnetic field of the induction motor is opposite to the inertial rotation direction of the rotor, and the direction of the electromagnetic torque is opposite to the rotor rotation direction, forming a braking torque, so that the mechanical kinetic energy of the rotor is quickly consumed and decelerated. The braking speed is fast and the vehicle can stop quickly.

[0049] It should be noted that when the vehicle brakes, the vehicle speed can be reduced from greater than the first preset vehicle speed to less than or equal to the first preset vehicle speed until it stops. During the braking process, direct current can be applied to the induction motor for energy consumption braking first. The advantages of smooth energy consumption braking can be utilized to ensure the stability and controllability of the vehicle during high-speed braking. Then, reverse alternating current is applied to the induction motor for plugging braking to avoid insufficient braking torque of energy consumption braking at low speed, resulting in too long braking distance of the vehicle.

[0050] The braking control method of a vehicle according to an embodiment of the present invention, the implemented braking function can be used to replace at least part of the braking function of the traditional hydraulic braking system of the vehicle. The vehicle can be equipped without or with a reduced hydraulic braking system to reduce the vehicle weight and manufacturing cost. Among them, reducing the hydraulic braking system can be reducing the number and size of brake discs and brake calipers, reducing the power of the brake cylinder, canceling the ABS system, etc.

[0051] In addition, the braking function implemented by this control method can also be used as a redundant backup for the vehicle's hydraulic braking system and regenerative braking (kinetic energy recovery), enabling the vehicle to perform deceleration braking through multiple braking methods. When the vehicle's hydraulic braking system fails or does not meet the conditions for regenerative braking, the braking control method of the embodiment of the present invention can be used for braking to reduce the risk of vehicle braking failure and improve the safety of the vehicle.

[0052] For the braking control method of a vehicle according to an embodiment of the present invention, when the vehicle brakes, if the vehicle speed is greater than the first preset speed, direct current is applied to the induction motor for energy consumption braking to ensure the stability and controllability of the vehicle during high-speed braking. If the vehicle speed is less than or equal to the first preset speed, reverse alternating current is applied to the induction motor for plugging braking to quickly generate reliable braking force when the vehicle is at low speed and ensure the vehicle stops.

[0053] In some embodiments of the present invention, the first preset speed is V1, satisfying the relationship 5 km / h ≤ V1 ≤ 20 km / h. For example, the first preset speed can be 5 km / h, 10 km / h, 15 km / h, or 20 km / h, etc.

[0054] It can be understood that if V1 > 20 km / h, plugging braking is adopted when the vehicle speed is relatively fast. When braking, the current value of the reverse alternating current to be applied is large, the energy consumption is high, and the induction motor generates serious heat. If V1 < 5 km / h, energy consumption braking is still adopted when the vehicle speed is relatively slow. The braking torque at low speed is small, resulting in an increase in the braking distance of the vehicle.

[0055] When 5 km / h ≤ V1 ≤ 20 km / h, energy consumption braking can be performed by applying direct current to the induction motor when the vehicle speed is relatively high to ensure the stability and controllability of the vehicle. When the vehicle is at low speed, plugging braking is performed by applying reverse alternating current to the induction motor to reduce the braking distance of the vehicle and improve the safety of the vehicle.

[0056] In some embodiments of the present invention, applying direct current to the induction motor for braking includes: obtaining the opening value of the brake pedal according to the braking signal, and controlling the current value of the direct current applied to the induction motor to be positively correlated with the opening value of the brake pedal.

[0057] It can be understood that the braking signal includes the opening value of the brake pedal, and the opening value of the brake pedal indicates the stroke of the driver pressing the brake pedal. The larger the opening value of the brake pedal, the greater the braking torque required by the vehicle. At the same time, when direct current is supplied to the induction motor for braking, the larger the current value of the direct current, the stronger the stator magnetic field of the induction motor, and thus the greater the braking torque generated. Therefore, by controlling the current value of the direct current supplied to the induction motor to be positively correlated with the opening value of the brake pedal, the larger the opening value of the brake pedal, the larger the current value of the direct current supplied to the induction motor, and the greater the braking torque generated by the induction motor, so as to adjust the braking torque accordingly according to the opening value of the brake pedal to meet the driver's control needs.

[0058] In some embodiments of the present invention, reverse alternating current is supplied to the induction motor for braking, including: obtaining the opening value of the brake pedal according to a braking signal, and controlling the current value of the reverse alternating current supplied to the induction motor to be positively correlated with the opening value of the brake pedal.

[0059] It can be understood that when the induction motor is braked by the reverse alternating current, the slip rate is greater than 1, and the braking torque is proportional to the square of the current. The larger the current value of the reverse alternating current passed through the induction motor, the stronger the braking torque. Therefore, by controlling the current value of the reverse alternating current passed through the induction motor to be positively correlated with the opening value of the brake pedal, the larger the opening value of the brake pedal, the larger the current value of the reverse alternating current passed through the induction motor, and the greater the braking torque generated by the induction motor. The braking torque can be adjusted accordingly according to the opening of the brake pedal to meet the driver's control needs.

[0060] Reference Figure 2 As shown, the power supply 5 can be a battery pack of the vehicle, and the power supply 5 can provide three-phase AC power to the induction motor 1 through the motor controller 6. When the vehicle is running, the phase sequence of the three-phase power output by the motor controller 6 corresponds to the interface of the induction motor 1, so that the rotor of the induction motor 1 drives the wheel 2 to rotate. When the vehicle brakes, the motor controller 6 can input DC power to the induction motor 1. In the three-phase power interface of the induction motor 1, the DC power can be single-phase input and two-phase output, or two-phase input and single-phase output, or single-phase input and single-phase output, so that the induction motor 1 enters an energy-consuming braking state, or the motor controller 6 can exchange any two phases of the three-phase power supplying the induction motor 1 (such as exchanging the U phase and the V phase) to make the induction motor 1 enter a reverse braking state. The above control process can be implemented through software control in the motor controller 6 without changing the hardware device of the motor controller 6.

[0061] In some embodiments of the present invention, the vehicle also includes: a permanent magnet motor and an energy consumption component, the permanent magnet motor is connected to the wheel transmission, the permanent magnet motor and the energy consumption component can be selectively electrically connected, and after receiving a braking signal, the vehicle's braking control method also includes: disconnecting the power supply of the permanent magnet motor, and controlling the energy consumption component to be electrically connected to the permanent magnet motor.

[0062] Specifically, the permanent magnet motor and the induction motor can drive the same or different wheels of the vehicle. The permanent magnet motor can be a permanent magnet synchronous motor. The energy consumption component is selectively electrically connected to the permanent magnet motor. The energy consumption component can be used to consume electric energy to achieve the braking function of the permanent magnet motor.

[0063] When the vehicle is traveling normally, the energy consumption component is disconnected from the permanent magnet motor, and the power supply supplies three-phase alternating current to the permanent magnet motor to drive the wheels to rotate. When the vehicle brakes, the power supply is controlled to disconnect the power supply to the permanent magnet motor, and the energy consumption component is controlled to be electrically connected to the permanent magnet motor, so that the permanent magnet motor and the energy consumption component form a closed loop. The permanent magnet motor enters the power generation mode. Due to inertia, the wheels drive the rotor of the permanent magnet motor to continue to rotate, thereby generating a back electromotive force, generating a current in the loop of the permanent magnet motor and the energy consumption component. The current flows through the energy consumption resistor and is converted into heat energy. At the same time, the current is subjected to a force in the magnetic field of the permanent magnet motor, generating a braking torque opposite to the rotation direction of the rotor, so that the rotor of the permanent magnet motor and the wheels decelerate until they stop.

[0064] In some embodiments of the present invention, the energy consumption component includes: a first energy consumption resistor, a first switch, a second energy consumption resistor, a second switch, a third energy consumption resistor, and a third switch. The first energy consumption resistor is selectively electrically connected to the first phase interface of the permanent magnet motor through the first switch. The second energy consumption resistor is selectively electrically connected to the second phase interface of the permanent magnet motor through the second switch. The third energy consumption resistor is selectively electrically connected to the third phase interface of the permanent magnet motor through the third switch.

[0065] Specifically, the permanent magnet motor has a first phase interface, a second phase interface, and a third phase interface, which can be respectively connected to the U, V, and W three-phase alternating currents to drive the wheels to rotate. The first switch can control whether the corresponding first energy consumption resistor is electrically connected to the first phase interface. The second switch can control whether the corresponding second energy consumption resistor is electrically connected to the second phase interface. The third switch can control whether the corresponding third energy consumption resistor is electrically connected to the third phase interface. When the vehicle is traveling normally, the first switch, the second switch, and the third switch are all in the off state to disconnect the electrical connection between the first energy consumption resistor, the second energy consumption resistor, and the third energy consumption resistor and the permanent magnet motor. When the vehicle brakes, at least two of the first switch, the second switch, and the third switch are turned on, so that the permanent magnet motor and the energy consumption component form a closed loop, and then the permanent magnet motor forms a braking torque.

[0066] It should be noted that the first energy consumption resistor, the second energy consumption resistor, and the third energy consumption resistor can be connected in parallel to the permanent magnet motor, so that the energy consumption component can carry a larger current, enabling the permanent magnet motor to generate a larger braking torque during braking. At the same time, when one of the first energy consumption resistor, the second energy consumption resistor, and the third energy consumption resistor is damaged, the other two can still form a circuit to ensure the braking function of the permanent magnet motor, making the energy consumption component have high reliability.

[0067] Referring Figure 3 As shown, the power supply 5 can provide three-phase alternating current to the permanent magnet motor through the motor controller 6. When the vehicle is running, the six semiconductor switches Q1, Q2, Q3, Q4, Q5, and Q6 of the motor controller 6 are all turned on, and the first switch 41, the second switch 42, and the third switch 43 of the energy consumption component 4 are all in the off state. The power supply 5 can supply power to the permanent magnet motor 3 through the motor controller 6 to drive the wheel 2 to rotate. When the vehicle brakes, the six semiconductor switches Q1, Q2, Q3, Q4, Q5, and Q6 of the motor controller 6 are all in the off state to cut off the power supply to the permanent magnet motor 3. At the same time, at least two of the first switch 41, the second switch 42, and the third switch 43 are turned on to brake the permanent magnet motor 3 through the energy consumption component 4.

[0068] In some embodiments of the present invention, controlling the electrical connection between the energy consumption component and the permanent magnet motor includes: obtaining the opening value of the brake pedal according to the braking signal, and controlling the duty ratios of the first switch, the second switch, and the third switch to be positively correlated with the opening value of the brake pedal.

[0069] Specifically, the first switch, the second switch, and the third switch can all be semiconductor switches. For example: IGBT (Insulated Gate Bipolar Transistor) switches. The duty ratios of the first switch, the second switch, and the third switch can be controlled by PWM (Pulse Width Modulation) signals, thereby adjusting the current flowing into the energy consumption component, and further realizing the control of the braking torque.

[0070] When controlling the duty ratios of the first switch, the second switch, and the third switch to be positively correlated with the opening value of the brake pedal, the larger the opening value of the brake pedal, the larger the duty ratios of the first switch, the second switch, and the third switch, the larger the current flowing through the energy consumption component, and the larger the braking torque generated by the permanent magnet motor, so as to adjust the braking torque corresponding to the opening of the brake pedal to meet the driver's control requirements.

[0071] In some embodiments of the present invention, the vehicle further includes a mechanical braking system, and the braking control method of the vehicle further includes: determining whether the current vehicle speed is less than or equal to a second preset vehicle speed. If the vehicle speed is less than or equal to the second preset vehicle speed, controlling the mechanical braking system to brake the wheels, where the second preset vehicle speed is less than the first preset vehicle speed.

[0072] Specifically, the second preset vehicle speed is V2, which satisfies the relationship 0 km / h ≤ V2 ≤ 2 km / h. For example, V2 is 0 km / h, 1 km / h, or 2 km / h, etc. The second preset vehicle speed is less than the first preset vehicle speed to brake the wheels through the mechanical braking system when the vehicle speed approaches or reaches 0 km / h, so as to achieve the final braking of the vehicle and maintain the parked state. Among them, the mechanical braking system can be a hydraulic braking system and / or a parking braking system, and both the hydraulic braking system and the parking braking system can achieve braking through mechanical structures such as brake pads and brake discs.

[0073] It can be understood that during braking, before the vehicle speed drops to the second preset vehicle speed, the induction motor is energized with reverse alternating current for plugging braking. When the vehicle speed reaches the second preset vehicle speed and the vehicle speed approaches or reaches 0 km / h, the reverse alternating current should be turned off to avoid the induction motor from reversing and prevent the vehicle from reversing after braking. At the same time, the mechanical braking system intervenes to make the vehicle finally brake and maintain the parked state.

[0074] During braking, before the vehicle speed drops to the second preset vehicle speed, the permanent magnet motor brakes by supplying power to the energy consumption component. When the vehicle speed reaches the second preset vehicle speed and the vehicle speed approaches or reaches 0 km / h, the generated current of the permanent magnet motor is small and the generated braking torque is small. At this time, the mechanical braking system intervenes to make the vehicle finally brake and maintain the parked state.

[0075] In some other embodiments of the present invention, referring to Figure 4 as shown, the braking control method of the vehicle includes the following steps:

[0076] Step S101, start.

[0077] Step S102, receive a braking signal.

[0078] Among them, when the driver steps on the brake pedal, a corresponding braking signal is generated, and the braking signal includes the opening value of the brake pedal.

[0079] Step S103, determine whether the preset conditions for regenerative braking are met. If so, execute step S104. If not, execute step S105.

[0080] Among them, the preset condition can be that the power of the vehicle battery pack is less than 95%. That is to say, if the power of the battery pack is less than 95%, the vehicle can turn on regenerative braking. If the power of the battery pack is greater than or equal to 95%, other braking methods are used.

[0081] Step S104, activate regenerative braking.

[0082] Among them, after activating regenerative braking, the induction motor and / or the permanent magnet motor generate regenerative power by recovering kinetic energy, and decelerate and brake the vehicle. The electric energy generated by recovering kinetic energy can charge the battery pack.

[0083] Step S105, determine whether the motor braking condition is satisfied. If yes, execute step S106 and / or step S109. If no, execute step S111.

[0084] Among them, the motor braking condition can be that the induction motor and / or the permanent magnet motor are working properly, and the motor temperature is less than 90 °C.

[0085] Step S106, when the motor is an induction motor, determine whether V0 > V1. If yes, execute step S107. If no, execute step S108.

[0086] Among them, V0 is the current vehicle speed, and V1 is the first preset vehicle speed. V1 can be 10 km / h. That is to say, when the current vehicle speed is greater than 10 km / h, execute step S107. When the current vehicle speed is less than or equal to 10 km / h, execute step S108.

[0087] Step S107, apply direct current to the induction motor for braking.

[0088] Among them, applying direct current to the induction motor can achieve energy consumption braking. By controlling the current value of the direct current applied to the induction motor to be positively correlated with the opening value of the brake pedal, the driver's control requirements can be met.

[0089] Step S108, apply reverse alternating current to the induction motor for braking.

[0090] Among them, applying reverse alternating current to the induction motor can achieve plugging braking. By controlling the current value of the reverse alternating current applied to the induction motor to be positively correlated with the opening value of the brake pedal, the driver's control requirements can be met.

[0091] Step S109, when the motor is a permanent magnet motor, disconnect the power supply of the permanent magnet motor and control the energy consumption component to be electrically connected to the permanent magnet motor.

[0092] Among them, the duty cycle of the IGBT switch of the energy consumption component can be positively correlated with the opening value of the brake pedal, and the driver's control requirements can be met.

[0093] Step S110, determine whether V0 ≤ V2. If yes, execute step S111. If no, return to step S105.

[0094] Among them, V0 is the current vehicle speed, V2 is the second preset vehicle speed, and V1 can be 2 km / h. That is to say, when the current vehicle speed is less than or equal to 2 km / h, step S111 is executed; when the current vehicle speed is greater than 2 km / h, return to step S105.

[0095] Step S111: Control the mechanical braking system to brake the wheels.

[0096] Among them, the mechanical braking system can be a hydraulic braking system and / or a parking braking system.

[0097] Through the vehicle braking control method of the above embodiments, when the vehicle brakes, the regenerative braking can be preferentially activated to achieve kinetic energy recovery and improve the vehicle's cruising range. When the battery pack has a high power level and the regenerative braking cannot be activated, braking can be performed through energy consumption braking, reverse connection braking, etc. During this process, the wheels and the rotor rotate continuously, and there is no need for the ABS (antilock braking system) to intervene, which can save the layout cost of the ABS system. When the vehicle speed is approaching zero, the vehicle can be braked to a stop by the mechanical braking system.

[0098] In addition, for the braking function implemented by the braking control method of the embodiments of the present invention, after the driver steps on the brake pedal, the control module can receive the braking signal within 1 millisecond and control the corresponding semiconductor switch to complete conduction or turn-off, quickly generating a braking torque to improve the sensitivity of the vehicle's braking operation.

[0099] It should be noted that the mechanical braking system of traditional vehicles includes a hydraulic braking system. The hydraulic braking system includes brake discs and brake calipers that match the four wheels. Each set weighs about 20 kg, and the four sets weigh about 80 kg. Coupled with the oil circuit, hydraulic pump and other structures of the hydraulic braking system, the total mass of the hydraulic braking system exceeds 100 kg. The hydraulic braking system increases the vehicle's self-weight and cost.

[0100] In some embodiments, for the braking function implemented by the vehicle braking control method of the embodiments of the present invention, the vehicle can eliminate the hydraulic braking system, thereby reducing the vehicle's self-weight and cost, avoiding the risk of oil leakage and environmental pollution of the hydraulic braking system, and also eliminating the power supply for the hydraulic pump, having a good environmental protection and energy-saving effect.

[0101] In other embodiments, for the braking function implemented by the vehicle braking control method of the embodiments of the present invention, the hydraulic braking system can be downsized. For example, the brake discs and brake calipers on the rear wheels can be eliminated, and the rated power of the hydraulic pump can be reduced, etc., thereby reducing the vehicle's self-weight and cost.

[0102] In some other embodiments, the braking function achieved by the braking control method of the vehicle according to the embodiments of the present invention can be used as a backup protection for the hydraulic braking system. When the hydraulic braking system fails, the vehicle can be braked by the braking control method of the vehicle according to the embodiments of the present invention to improve the safety of the vehicle.

[0103] In some embodiments of the present invention, the vehicle may be provided with two permanent magnet motors. The front and rear wheels of the vehicle are driven by different permanent magnet motors. The power of the permanent magnet motor is 120 kw, the voltage is 380 V, and the rated current is 200 A. The total mass of the vehicle after carrying people is 2000 kg. When the vehicle is traveling normally on the road at 100 km / h, the kinetic energy of the vehicle's current linear motion is W = 0.5mv 2 = 771605 J. When the driver brakes emergently, the power supply to the permanent magnet motor is disconnected. The first switch, the second switch, and the third switch of the energy consumption component are switched from off to on. The first energy consumption resistor, the second energy consumption resistor, and the third energy consumption resistor can all be 0.5-ohm resistors. The short-time current of the first switch, the second switch, and the third switch of the permanent magnet motor and the semiconductor device is generally twice the rated current or more, and the short-time average effective current is selected as 400 A. The energy consumption of the three resistors in two seconds is 3 * I 2 *R*T = 480000 J. The energy consumption components corresponding to the two permanent magnet motors can consume a total of 960000 J of energy, which can fully cover the kinetic energy of the vehicle's linear motion to achieve a better braking effect.

[0104] In some other embodiments of the present invention, the vehicle may be provided with an induction motor and a permanent magnet motor. One of the induction motor and the permanent magnet motor can drive the front wheels of the vehicle, and the other can drive the rear wheels of the vehicle. The power of the induction motor is 180 kw, the power of the permanent magnet motor is 240 kw, the voltage is 300 V, and the DC bus is 400 V. When the vehicle is traveling normally on the road at 100 km / h, the kinetic energy of the vehicle's current linear motion is W = 0.5mv 2 = 771605 J. When the driver brakes emergently, the induction motor decelerates through energy consumption braking or reverse connection braking, and the permanent magnet motor decelerates by consuming power through the energy consumption component.

[0105] According to the computer-readable storage medium of the second aspect embodiment of the present invention, a braking control program of a vehicle is stored thereon. When the braking control program of the vehicle is executed by a processor, the braking control method of the vehicle in the above embodiments is implemented.

[0106] According to the computer-readable storage medium of an embodiment of the present invention, through the above-mentioned vehicle braking control method, when the vehicle brakes, if the vehicle speed is greater than a first preset speed, direct current is supplied to the induction motor for energy-consuming braking to ensure the stability and controllability of the vehicle when braking at high speeds; if the vehicle speed is less than or equal to the first preset speed, reverse alternating current is supplied to the induction motor for reverse braking to quickly generate reliable braking force when the vehicle is at a low speed to ensure that the vehicle stops.

[0107] According to the vehicle controller of the third aspect embodiment of the present invention, it includes a memory, a processor and a vehicle braking control program stored in the memory and executable on the processor. When the processor executes the vehicle braking control program, the vehicle braking control method of the above embodiment is implemented.

[0108] According to the vehicle controller of an embodiment of the present invention, through the above-mentioned vehicle braking control method, when the vehicle brakes, if the vehicle speed is greater than a first preset speed, direct current is supplied to the induction motor for energy-consuming braking to ensure the stability and controllability of the vehicle when braking at high speed. If the vehicle speed is less than or equal to the first preset speed, reverse alternating current is supplied to the induction motor for reverse braking to quickly generate reliable braking force when the vehicle is at a low speed to ensure that the vehicle stops.

[0109] According to the vehicle braking control device of the fourth aspect embodiment of the present invention, the vehicle includes: an induction motor and wheels, the induction motor is drivingly connected to the wheels, and the vehicle braking control device includes: a receiving module and a control module, the receiving module is used to receive a braking signal, and the control module is used to determine whether the current vehicle speed is greater than a first preset vehicle speed. If the current vehicle speed is greater than the first preset vehicle speed, direct current is supplied to the induction motor for braking. If the current vehicle speed is less than or equal to the first preset vehicle speed, reverse alternating current is supplied to the induction motor for braking.

[0110] According to the braking control device of a vehicle in an embodiment of the present invention, when the vehicle is braking, if the vehicle speed is greater than a first preset speed, the control module can control the induction motor to pass direct current for energy-consuming braking to ensure the stability and controllability of the vehicle when braking at high speed. If the vehicle speed is less than or equal to the first preset speed, the control module can control the induction motor to pass reverse alternating current for reverse braking to quickly generate reliable braking force when the vehicle is at a low speed to ensure that the vehicle stops.

[0111] In some embodiments of the present invention, the first preset vehicle speed is V1, which satisfies the relationship 5km / h≤V1≤20km / h.

[0112] In some embodiments of the present invention, the control module is further used to obtain the opening value of the brake pedal according to the brake signal, and control the current value of the direct current passed into the induction motor to be positively correlated with the opening value of the brake pedal.

[0113] In some embodiments of the present invention, the control module is further configured to obtain the opening value of the brake pedal according to the brake signal, and control the current value of the reverse alternating current applied to the induction motor to be positively correlated with the opening value of the brake pedal.

[0114] In some embodiments of the present invention, the vehicle further includes: a permanent magnet motor and an energy consumption component. The permanent magnet motor is drivingly connected to the wheel, and the permanent magnet motor is selectively electrically connected to the energy consumption component. After receiving the brake signal, the control module is further configured to disconnect the power supply of the permanent magnet motor and control the energy consumption component to be electrically connected to the permanent magnet motor.

[0115] In some embodiments of the present invention, the energy consumption component is installed on the permanent magnet motor. The energy consumption component includes: a first energy consumption resistor and a first switch. The first energy consumption resistor is selectively electrically connected to the first phase interface of the permanent magnet motor through the first switch, a second energy consumption resistor and a second switch. The second energy consumption resistor is selectively electrically connected to the second phase interface of the permanent magnet motor through the second switch, a third energy consumption resistor and a third switch. The third energy consumption resistor is selectively electrically connected to the third phase interface of the permanent magnet motor through the third switch.

[0116] In some embodiments of the present invention, the control module is further configured to obtain the opening value of the brake pedal according to the brake signal, and control the duty cycles of the first switch, the second switch, and the third switch to be positively correlated with the opening value of the brake pedal.

[0117] In some embodiments of the present invention, the vehicle further includes a mechanical braking system. The control module is further configured to determine whether the current vehicle speed is less than or equal to a second preset vehicle speed. If the previous vehicle speed is less than or equal to the second preset vehicle speed, then control the mechanical braking system to brake the wheel, wherein the second preset vehicle speed is less than the first preset vehicle speed.

[0118] It should be noted that the specific implementation manner of the braking control device of the vehicle in the embodiments of the present invention is of the same type as the implementation manner of the braking control method of the vehicle in the embodiments of the present invention. For details, refer to the description in the method part. To reduce redundancy, it will not be elaborated here.

[0119] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0120] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A braking control method for a vehicle, characterized in that, The vehicle includes: an induction motor and a wheel, the induction motor is drivingly connected to the wheel, and the braking control method of the vehicle includes: Receiving a braking signal; Judging whether the current vehicle speed is greater than a first preset vehicle speed; If the current vehicle speed is greater than the first preset vehicle speed, direct current is applied to the induction motor for braking; If the current vehicle speed is less than or equal to the first preset vehicle speed, reverse alternating current is applied to the induction motor for braking.

2. The braking control method of a vehicle according to claim 1, characterized in that, The first preset vehicle speed is V1, and it satisfies the relationship 5 km / h ≤ V1 ≤ 20 km / h.

3. The braking control method of a vehicle according to claim 1, characterized in that, Applying direct current to the induction motor for braking includes: obtaining the opening value of the brake pedal according to the braking signal, and controlling the current value of the direct current applied to the induction motor to be positively correlated with the opening value of the brake pedal; Applying reverse alternating current to the induction motor for braking includes: obtaining the opening value of the brake pedal according to the braking signal, and controlling the current value of the reverse alternating current applied to the induction motor to be positively correlated with the opening value of the brake pedal.

4. The braking control method of a vehicle according to any one of claims 1-3, characterized in that, The vehicle further includes: a permanent magnet motor and an energy consumption component, the permanent magnet motor is drivingly connected to the wheel, and the permanent magnet motor is selectively electrically connected to the energy consumption component. After receiving the braking signal, the braking control method of the vehicle further includes: Disconnecting the power supply of the permanent magnet motor and controlling the energy consumption component to be electrically connected to the permanent magnet motor.

5. The braking control method of a vehicle according to claim 4, characterized in that, The energy consumption component includes: A first energy consumption resistor and a first switch, the first energy consumption resistor is selectively electrically connected to the first phase interface of the permanent magnet motor through the first switch; A second energy consumption resistor and a second switch, the second energy consumption resistor is selectively electrically connected to the second phase interface of the permanent magnet motor through the second switch; A third energy consumption resistor and a third switch, the third energy consumption resistor is selectively electrically connected to the third phase interface of the permanent magnet motor through the third switch.

6. The braking control method for a vehicle according to claim 5, wherein, Controlling the energy consumption component to be electrically connected to the permanent magnet motor includes: Obtaining the opening value of the brake pedal according to the braking signal, and controlling the duty ratios of the first switch, the second switch, and the third switch to be positively correlated with the opening value of the brake pedal.

7. The braking control method of a vehicle according to claim 1, characterized in that, The vehicle further includes a mechanical braking system, and the braking control method of the vehicle further includes: Judging whether the current vehicle speed is less than or equal to a second preset vehicle speed; If the previous vehicle speed is less than or equal to the second preset vehicle speed, controlling the mechanical braking system to brake the wheel; Wherein, the second preset vehicle speed is less than the first preset vehicle speed.

8. A computer-readable storage medium, characterized in that, A vehicle braking control program is stored thereon, and when the vehicle braking control program is executed by a processor, the vehicle braking control method according to any one of claims 1-7 is implemented.

9. A vehicle controller, characterized in that, It includes a memory, a processor, and a vehicle braking control program stored on the memory and executable on the processor. When the processor executes the vehicle braking control program, the vehicle braking control method according to any one of claims 1-7 is implemented.

10. A braking control device for a vehicle, characterized in that, The vehicle includes: an induction motor and a wheel, the induction motor is drivingly connected to the wheel, and the braking control device of the vehicle includes: Receiving module, configured to receive a braking signal; Control module, configured to determine whether the current vehicle speed is greater than a first preset vehicle speed. If the current vehicle speed is greater than the first preset vehicle speed, direct current is applied to the induction motor for braking. If the current vehicle speed is less than or equal to the first preset vehicle speed, reverse alternating current is applied to the induction motor for braking.

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