Control unit to regulate torque during wheel spin in vehicle

Abstract

To provide a control unit to regulate a torque during a wheel spin in a vehicle.SOLUTION: A control unit 10 detects a wheel 11 spin on the basis of a variation in a vehicle parameter and activates a traction control module 14 to calculate and reduce a demanded torque during a wheel spin moment. The control unit 10 calculates a target torque from a plurality of the vehicle parameters and is provided as a desired torque from an inverter unit 16 after comparing the target torque with the demanded torque. The control unit 10 regulates the desired torque in sequential steps by controlling phase currents required by the inverter unit 16.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control unit for adjusting torque when wheels of a vehicle are spinning. [Background technology]

[0002] Background technology In some electric motorcycles used on or off the road, risks such as loss of traction and unintended vehicle acceleration and deceleration are assessed by ASIL according to the ISO 26262 functional safety standard. To mitigate these risks, it is necessary to monitor the torque delivered to the wheels. In the current idea, we simplified the monitoring of the traction control torque by monitoring its maximum and minimum values ​​as well as its maximum and minimum gradients. This prevents unintended acceleration and deceleration of the vehicle when the traction control of the motorcycle is activated.

[0003] U.S. Patent Application Publication No. 20090132123 discloses a wheel spin control device for a vehicle that, when it is determined that wheel spin is occurring, reduces engine torque to prevent wheel spin. Reducing engine torque to prevent wheel spin includes detecting drive control information and information related to the vehicle state, and determining whether basic conditions necessary for preventing wheel spin by executing engine torque limit control are met. If the basic conditions are met, the device calculates a speed fluctuation and a speed gradient value, compares the speed gradient value with a predetermined speed gradient value, and determines whether wheel spin is occurring. If it is determined that wheel spin is occurring, the device executes engine torque limit control using a torque gradient map set according to the current engine torque. The vehicle speed decreases due to engine torque limit control, and when a release condition is met, the engine torque limit control is released and normal control is restored. [Brief explanation of the drawings]

[0004] [Figure 1]FIG. 2 illustrates a control unit for adjusting torque during wheel spin in a vehicle according to one embodiment of the present invention. [Figure 2] FIG. 1 shows a flow chart of a method for adjusting torque according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0005] MODE FOR CARRYING OUT THE INVENTION 1 illustrates a control unit for performing tasks associated with components according to one embodiment of the present invention. Control unit 10 detects wheel spin 11 based on variations in vehicle parameters and activates traction control module 14 to calculate and reduce the required torque during wheel spin. Control unit 10 calculates a target torque from multiple vehicle parameters and compares the target torque with the required torque, which is then provided as a desired torque by inverter unit 16. Control unit 10 adjusts the desired torque step by step by controlling the phase currents required by inverter unit 16.

[0006] The configuration of the control unit 10 and its associated components will be described in detail. The control unit 10 is a logic circuit and software program implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, state machines, logic circuits, and / or any other components that operate based on signals in response to operational instructions. The vehicle parameters are selected from a group of vehicle parameters including electric motor speed gradient (RPM / sec), throttle grip position, motor speed (RPM), and RPM gradient. However, it should be understood that the vehicle parameters may be any other parameters known in the art. The control unit 10 includes a memory 22 that stores multiple target torques mapped to corresponding multiple rider-requested torques. In real time, the control unit 10 provides the desired torque from the inverter unit 16 by selecting one of the rider-requested torques mapped to the calculated target torques.

[0007] Inverter unit 16 supplies electric motor 18 of vehicle 12 with the phase currents necessary to generate the desired torque. Control unit 10 continuously monitors the incremental increase in desired torque to maintain the desired torque within predetermined limits. During a fault, control unit 10 identifies the fault when it senses the desired torque exceeding the predetermined limits. Torque limit module 20 of control unit 10 is activated upon detection of the fault to maintain a safe limit torque.

[0008] 2 is a flowchart of a method for adjusting torque according to the present invention. In step S1, wheel spin is detected based on variations in vehicle parameters. In step S2, the traction control module 14 is activated to calculate and reduce the required torque when the wheel 11 is spinning. In step S3, a target torque is calculated from a plurality of vehicle parameters, and after comparing the target torque with the required torque, the target torque is provided as the desired torque from the inverter unit 16. In step S4, the desired torque is adjusted stepwise by controlling the phase current required by the inverter unit 16.

[0009] The method will now be described in detail. The control unit 10 activates the traction control module 14 upon detecting a variation in any vehicle parameter that causes a wheel spin condition. One such parameter in the present invention is the electric motor speed gradient (RPM / sec). When the traction control module 14 is activated, the rider's requested torque is reduced to avoid wheel 11 spin. The traction control module 14 calculates the target torque to be reduced. When the traction control module 14 is activated, the control unit 10 monitors the target torque reduction by monitoring the torque gradient (Nm / sec) and its minimum value. The target torque reduction is always below the rider's requested torque and the minimum value. A faster target torque reduction and exceeding the minimum value will cause unintended deceleration of the vehicle 12.

[0010] This target torque is coordinated with the rider's requested torque, and the request is sent to the inverter unit. The requested torque is referred to as the desired torque, which is the output of the inverter unit. The desired torque is derived from the rider's requested torque and the target torque, and the inverter unit generates the necessary phase currents in the electric motor to generate the desired torque that matches the rider's requested torque. When the traction control module is turned off, the target torque increases to the rider's requested torque, and a faster increase and exceeding the rider's requested torque can cause uncontrollable acceleration.

[0011] The control unit 10 monitors the desired torque and maintains a gradual increase in torque rather than a sudden increase in desired torque. The control unit 10 detects a fault in at least one component of the vehicle 12 and senses a sudden torque surge due to the fault. Upon detecting the fault, the control unit 10 issues a request to the inverter unit 16 to maintain a safe torque (in this case, the desired torque). The control unit 10 calculates the allowable torque based on an independent and redundant calculation of the rider's requested torque with tolerances added.

[0012] It should be understood that the embodiments described in the foregoing description are exemplary only and do not limit the scope of the invention. Many such embodiments and other modifications and variations of the embodiments described herein are contemplated. The scope of the invention is limited only by the claims.

Claims

1. A control unit (10) for adjusting torque during wheel spin of a vehicle (12), comprising: The control unit (10) Detecting wheel spin (11) based on variations in vehicle parameters; activating a traction control module (14) to calculate and reduce torque demands when the wheels are spinning; calculating a target torque from a plurality of vehicle parameters, comparing the target torque with the required torque, and then providing the target torque as a desired torque from the inverter unit (16); The desired torque is adjusted step by step by controlling the phase current required by the inverter unit (16). The control unit (10) is configured as follows.

2. The vehicle parameter is selected from a group of vehicle parameters including electric motor speed gradient (RPM / sec), throttle grip position, motor speed (RPM), RPM gradient; A control unit (10) according to claim 1.

3. The calculated target torque is mapped to a rider's requested torque, and the target torque is provided as a desired torque from an inverter unit (16). A control unit (10) according to claim 1.

4. The inverter unit (16) is configured to supply the phase currents required by the vehicle's electric motor (18) to generate the desired torque. A control unit (10) according to claim 1.

5. The control unit (10) continuously monitors the incremental increase in the desired torque and maintains the desired torque within predetermined limits. A control unit (10) according to claim 1.

6. The control unit (10) is configured to detect a fault when it senses the desired torque exceeding the predetermined limit. A control unit (10) according to claim 1.

7. Upon detecting a fault, a torque limiting module (20) is activated to maintain a safe torque limit. A control unit (10) according to claim 6.

8. A method for adjusting torque during wheel spin on a vehicle, comprising: The method comprises: detecting wheel spin by a control unit (10) based on variations in vehicle parameters; activating a traction control module (14) to calculate and reduce torque demands when the wheels are spinning; calculating a target torque from a plurality of vehicle parameters, comparing the target torque with the required torque, and then providing the target torque as a desired torque from an inverter unit (16); adjusting the desired torque step by step by controlling the phase currents required by the inverter unit (16); A method comprising:

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