Vehicle slip power control system and control method thereof

Abstract

To provide a vehicle slip power control system and its control method capable of effectively coping with the slip of a wheel.SOLUTION: A front wheel speed sensor, a rear wheel speed sensor, a control unit provided with a preset slip threshold and configured to calculate a slip ratio according to a front wheel speed and a rear wheel speed, and a PID control module coupled to the control unit and configured to adjust an output torque of the vehicle according to the slip ratio; And a PID control module, where the PID control module includes an increase-type PID control unit in which a torque increase calculation formula is pre-stored and a decrease-type PID control unit in which a torque decrease calculation formula is pre-stored, and when the slip ratio exceeds a preset slip threshold, the control unit triggers the PID control module to select the increase-type PID control unit or the decrease-type PID control unit to adjust the output torque according to the slip ratio.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle slip dynamics control system, and more particularly to a system that uses the speed difference between the front and rear wheels to calculate the slip ratio and adjusts the output torque using a specific PID control algorithm. [Background technology]

[0002] When a vehicle is traveling, a lack of grip between the drive tires and the road surface causes slippage. Slippage not only reduces the vehicle's maneuverability and fuel efficiency, but in severe cases can even cause the vehicle to spin out of control. Therefore, effectively preventing wheel slippage and maintaining good traction are extremely important for safe driving.

[0003] Conventional technologies typically measure the rotational speed of wheels, calculate the wheel slip ratio based on the difference in rotational speed, and then adjust the engine output torque or braking torque based on the slip ratio to prevent slippage. However, this passive response method has a delay and cannot provide immediate and accurate control, making it impossible to effectively resolve slippage and potentially causing the risk of recurrence due to excessive correction.

[0004] In addition, conventional technologies generally use a single PID control parameter to adjust the output torque, which lacks the ability to distinguish between different slip conditions, making it difficult to make dynamic judgments and accurately respond, and resulting in relatively limited control precision and immediacy.Some technologies attempt to use complex fuzzy logic or neural network algorithms, but these require complex models, difficult parameter adjustment, and large amounts of real-time calculation, making them difficult to implement in embedded systems. Summary of the Invention [Problem to be solved by the invention]

[0005] Wheel slippage is likely to occur during vehicle operation, especially on wet or uneven road surfaces. To prevent vehicle runaway and ensure driving safety, conventional traction control systems (TCSs) have been proposed, which control wheel slippage by adjusting the vehicle's output torque. However, conventional control systems can suffer from slow response speed and poor stability when dealing with dynamically changing slip ratios. Furthermore, many vehicles only use a single-mode PID controller to adjust torque, which may not achieve optimal results under different road surface conditions. Wheel slippage or runaway is particularly likely to occur on wet or uneven road surfaces. Therefore, an improved control system that can more effectively address wheel slippage is needed. [Means for solving the problem]

[0006] The present invention provides a vehicle slip dynamic control system for use in a vehicle, the vehicle slip dynamic control system including: a front wheel speed sensor; a rear wheel speed sensor; a control unit having a preset slip critical value and calculating a slip ratio based on the front wheel speed and the rear wheel speed; and a PID control module coupled to the control unit and adjusting the vehicle output torque based on the slip ratio, the PID control module including an ascending-type PID control unit having a torque increase calculation formula pre-stored therein and a descending-type PID control unit having a torque decrease calculation formula pre-stored therein. When the slip ratio exceeds the preset slip critical value, the control unit triggers the PID control module to selectively use the ascending-type PID control unit or the descending-type PID control unit based on the magnitude of the slip ratio to adjust the output torque.

[0007] In one embodiment, the torque rise calculation formula is Yn=Rising_P*ΔXn+Rising_I*ΣΔXn+Rising_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Rising_P*ΔXn is the calculation of the proportional control amount, Rising_I*ΣΔXn is the calculation of the integral control amount, and Rising_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and these control amounts are added together to obtain the output torque Yn.

[0008] In one embodiment, the torque reduction calculation formula is Yn=Falling_P*ΔXn+Falling_I*ΣΔXn+Falling_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Falling_P*ΔXn is the calculation of the proportional control amount, Falling_I*ΣΔXn is the calculation of the integral control amount, and Falling_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and these control amounts are added together to obtain the output torque Yn.

[0009] In one embodiment, the slip ratio calculation formula is slip ratio = front wheel speed / rear wheel speed, and if the slip ratio exceeds a preset slip critical value, the PID control module is triggered to operate.

[0010] In one embodiment, the control unit further includes calculating a slip compensation value using a formula: slip compensation value = torque * slip value.

[0011] The present invention also provides a control method for a vehicle slip dynamic control system, which includes: measuring a front wheel speed and a rear wheel speed; receiving the front wheel speed and the rear wheel speed through a control unit, calculating a slip ratio; determining whether the slip ratio exceeds a preset slip critical value; and if the slip ratio exceeds the critical value, selecting and using an ascending-type PID control unit or a descending-type PID control unit based on the slip ratio to adjust the output torque.

[0012] In one embodiment, when the rising PID control unit operates, it includes the steps of calculating the current control error ΔXn, calculating the proportional control amount Rising_P*ΔXn, calculating the integral control amount Rising_I*ΣΔXn, calculating the differential control amount Rising_D*(ΔXn-ΔX(n-1)), and adding these control amounts to obtain the output torque Yn.

[0013] In one embodiment, when a descending PID control unit operates, the process includes the steps of calculating a current control error ΔXn, calculating a proportional control amount Falling_P*ΔXn, calculating an integral control amount Falling_I*ΣΔXn, calculating a differential control amount Falling_D*(ΔXn-ΔX(n-1)), and adding these control amounts to obtain an output torque Yn.

[0014] In one embodiment, the calculation step to calculate slip includes: slip ratio = front wheel speed / rear wheel speed, and if the slip ratio exceeds a preset slip critical value, the PID control module is triggered to operate.

[0015] To enable a detailed understanding of the features described herein, the above brief summary of the invention, but a more particular description thereof, can be made by reference to embodiments, some of which are illustrated in the drawings. It should be noted, however, that the drawings illustrate only typical embodiments of the invention and should not be considered as limiting its scope, since the invention is susceptible to other embodiments that are equally effective. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram of a system configuration of the present invention. [Figure 2] 1 is a schematic diagram of an operation of the present invention; [Figure 3] 1 is a schematic diagram of the steps of carrying out the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0017] The following description includes specific information related to exemplary embodiments of the present invention. The drawings and detailed description of the present invention are merely exemplary embodiments. However, the present invention is not limited to these exemplary embodiments. Other variations and embodiments of the present invention will occur to those skilled in the art. Unless otherwise stated, like or corresponding elements in the drawings may be indicated by like or corresponding reference numerals. Additionally, the drawings and illustrations of the present invention are generally not drawn to scale and do not necessarily correspond to actual relative sizes.

[0018] For purposes of consistency and ease of understanding, like features are designated by numerals in the exemplary drawings (although in some instances they are not so designated), but should not be limited narrowly to the features shown in the drawings, as features in different embodiments may differ in other respects.

[0019] Terms such as "at least one embodiment," "one embodiment," "multiple embodiments," "different embodiments," "some embodiments," "the present embodiment," and the like can indicate that the embodiments of the invention so described may include a particular feature, structure, or characteristic, but not all possible embodiments of the invention must include that particular feature, structure, or characteristic. Furthermore, repeated use of the phrases "in one embodiment" and "in this embodiment" does not necessarily refer to the same embodiment, even if they may be the same. Furthermore, when used in the context of "the present invention," phrases such as "embodiment" and "present embodiment" do not imply that all embodiments of the invention must include that particular feature, structure, or characteristic; rather, "at least some embodiments of the present invention" should be understood to include the described particular feature, structure, or characteristic. The term "coupled" is defined as connected, whether directly or indirectly through intervening elements, and is not necessarily limited to a physical connection. When the term "comprising" is used, it means "including, but not limited to," and explicitly indicates an open-ended inclusion or relationship of listed combinations, groups, series, and equivalents.

[0020] Also, for purposes of explanation and not limitation, specific details of functional entities, techniques, protocols, standards, etc. are set forth to provide an understanding of the described technology. In other instances, detailed descriptions of well-known methods, techniques, systems, architectures, etc. are omitted so as not to obscure the description with unnecessary detail.

[0021] As shown in Figure 1, Figure 1 is a schematic diagram of the system configuration of the present invention. The present invention provides a vehicle slip dynamics control system 10 for use in a vehicle 11, such as an automobile, motorcycle, or other vehicle. The vehicle slip dynamics control system 10 includes a front wheel speed sensor 101, a rear wheel speed sensor 102, a control unit 103, and a PID control module 104. The front wheel speed sensor 101 is used to measure the front wheel speed M1 of the vehicle 11, and the rear wheel speed sensor 102 is used to measure the rear wheel speed M2 of the vehicle 11. The control unit 103 may be, for example, a microprocessor or microcontroller (MCU), and performs tasks such as calculation, data processing, and control command transmission. The control unit 103 is provided with a preset slip critical value M3. The control unit 103 is coupled to the front wheel speed sensor 101 and the rear wheel speed sensor 102, respectively, and is capable of receiving the front wheel speed M1 and the rear wheel speed M2 and calculating a slip ratio based on the front wheel speed M1 and the rear wheel speed M2. In one embodiment, the control unit 103 further calculates a slip compensation value using a formula: slip compensation value = torque * slip value. The PID control module 104 is a proportional-integral-derivative controller primarily used to precisely adjust the output torque of the vehicle 11 to accommodate different driving conditions and prevent wheel slip. The PID control module 104 is coupled to the control unit 103 and adjusts the output torque of the vehicle 11 based on the slip ratio. The PID control module 104 further includes an ascending-type PID control unit 1041 having a torque increase calculation formula M4 pre-stored therein and a descending-type PID control unit 1042 having a torque decrease calculation formula M5 pre-stored therein. When the slip ratio exceeds a preset slip critical value M3, the control unit 103 triggers the PID control module 104 to selectively use the ascending-type PID control unit 1041 or the descending-type PID control unit 1042 to adjust the output torque based on the magnitude of the slip ratio. In one embodiment, the slip ratio calculation formula is: slip ratio = front wheel speed / rear wheel speed.If the slip ratio exceeds the preset slip critical value M3, the PID control module 104 is triggered to operate.

[0022] As shown in FIG. 1, in one embodiment, torque increase calculation formula M4 is Yn=Rising_P*ΔXn+Rising_I*ΣΔXn+Rising_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Rising_P*ΔXn is the calculation of the proportional control amount, Rising_I*ΣΔXn is the calculation of the integral control amount, and Rising_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and the output torque Yn is obtained by adding these control amounts.

[0023] As shown in FIG. 1, in one embodiment, the torque reduction calculation formula M5 is Yn=Falling_P*ΔXn+Falling_I*ΣΔXn+Falling_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Falling_P*ΔXn is the calculation of the proportional control amount, Falling_I*ΣΔXn is the calculation of the integral control amount, and Falling_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and the output torque Yn is obtained by adding these control amounts.

[0024] Referring to FIG. 2, FIG. 2 is a schematic diagram of an implementation of the present invention. Also referring to FIG. 1, when the present invention is implemented, a front wheel speed sensor 101 and a rear wheel speed sensor 102 measure the front wheel speed M1 and the rear wheel speed M2 of a vehicle 11, respectively. A control unit 103 calculates a slip ratio based on the difference in rotational speed between the front and rear wheels. If the slip ratio exceeds a preset slip threshold M3, the control unit 103 triggers the PID control module 104 to operate. The algorithm employed by the PID control module 104 includes an ascending PID control unit 1041 and a descending PID control unit 1042. Based on the magnitude of the slip ratio, the control unit 103 selects and uses the ascending PID control unit 1041 or the descending PID control unit 1042 to perform control. When the slip ratio is large and continuously increasing, i.e., ΔXn>ΔX(n-1), it indicates severe wheel slip, and in this case, the control unit 103 activates the ascending PID control unit 1041. The formula for the ascending PID control unit 1041 is Yn=Rising_P*ΔXn+Rising_I*ΣΔXn+Rising_D*(ΔXn-ΔX(n-1)). Yn is the current torque control amount output, and Rising_P, Rising_I, and Rising_D are three control parameters: proportional, integral, and differential. This formula basically linearly combines the current control error ΔXn and its integral and derivative to generate a reasonable output torque Yn, thereby restoring more grip to the wheels and suppressing the rate of slip. As a result, even when slip occurs, the output torque increases steadily, avoiding a decrease in the coupling effect due to a sudden change.

[0025] On the other hand, if the slip ratio is large but starts to decrease, i.e., ΔXn<ΔX(n-1), it indicates that the wheel grip force is recovering, and in this case, the control unit 103 activates the descending PID control unit. The formula of the descending PID control unit is Yn=Falling_P*ΔXn+Falling_I*ΣΔXn+Falling_D*(ΔXn-ΔX(n-1)), where Falling_P, Falling_I, and Falling_D are specially adjusted PID parameters. This formula gently reduces the output torque Yn, preventing loss of grip force due to excessive slip compensation.

[0026] As can be seen from the above, the separated design of the ascending PID control unit 1041 and the descending PID control unit 1042 mainly avoids the problem of a single PID parameter being canceled out under different slip conditions, making the control response more reasonable and efficient. In further practical applications, the calculation period of the system is set to 5 milliseconds, i.e., 200 calculations per second, to ensure high immediacy.

[0027] Referring to Fig. 3, Fig. 3 is a schematic diagram of the implementation steps of the present invention. Referring also to Figs. 1 and 2, the implementation method of the vehicle slip dynamic control system 10 of the present invention is as follows. First step S1: Measure the front wheel speed M1 and rear wheel speed M2. Second step S2: The control unit 103 receives the front wheel speed M1 and the rear wheel speed M2 and then calculates the slip ratio. In one embodiment, the slip ratio calculation formula is: slip ratio = front wheel speed / rear wheel speed. If the slip ratio exceeds a preset slip critical value M3, the PID control module 104 is triggered to operate. Third step S3: Determine whether the slip rate exceeds a preset slip critical value M3. Fourth step S4: If the slip ratio exceeds the preset slip critical value M3, select and use the ascending PID control unit 1041 or the descending PID control unit 1042 based on the slip ratio to adjust the output torque.

[0028] Referring to FIG. 3, in one embodiment, when the rising PID control unit 1041 operates, it includes the steps of calculating a current control error ΔXn, calculating a proportional control amount Rising_P*ΔXn, calculating an integral control amount Rising_I*ΣΔXn, calculating a differential control amount Rising_D*(ΔXn-ΔX(n-1)), and adding these control amounts to obtain an output torque Yn.

[0029] Referring to FIG. 3, in one embodiment, when the descending PID control unit 1042 operates, it includes the steps of calculating the current control error ΔXn, calculating the proportional control amount Falling_P*ΔXn, calculating the integral control amount Falling_I*ΣΔXn, calculating the differential control amount Falling_D*(ΔXn-ΔX(n-1)), and adding these control amounts to obtain the output torque Yn.

[0030] 3, in one embodiment, the calculation step for calculating the slip ratio includes: Slip ratio = Front wheel speed / Rear wheel speed If the slip ratio exceeds a preset slip critical value M3, the PID control module 104 is triggered to operate.

[0031] Referring to FIG. 3, in one embodiment, the control unit 103 further includes calculating a slip compensation value using a formula: slip compensation value=torque*slip value.

[0032] In summary, the vehicle slip dynamics control system of the present invention can respond more accurately and quickly to changes in slip ratio, instantly adjust the driving torque, and effectively prevent slip. By providing an ascending PID controller and a descending PID controller for increasing and decreasing slip ratios, respectively, the control response becomes more reasonable and stable, and slip compensation is added to the PID control, further improving the precision of traction control, thereby achieving the objectives of a short control period, high calculation accuracy, and immediate and efficient control effect.

[0033] The scope of these embodiments and patent applications does not necessarily need to achieve all of the disclosed technical advantages or technical features. Furthermore, the abstracts and titles are merely intended to facilitate searching of patent application documents and are not intended to limit the category of the present invention in any way. [Explanation of symbols]

[0034] 10: Vehicle slip power control system 101: Front wheel speed sensor 102: Rear wheel speed sensor 103: Control unit 104: PID control module 1041: Ascending PID control unit 1042: Descending PID control unit 11: Vehicle S1: First step S2: Second step S3: The third step S4: The fourth step M1: Front wheel speed M2: Rear wheel speed M3: Preset slip threshold M4: Torque increase calculation formula M5: Torque reduction calculation formula

Claims

1. Used in vehicles, a front wheel speed sensor for measuring a front wheel speed of the vehicle; a rear wheel speed sensor for measuring a rear wheel speed of the vehicle; a control unit having a preset slip threshold value, coupled to the front wheel speed sensor and the rear wheel speed sensor, respectively, for calculating a slip ratio based on the front wheel speed and the rear wheel speed; a PID control module coupled to the control unit and configured to adjust an output torque of the vehicle based on the slip ratio, the PID control module including an ascending-type PID control unit in which a torque increase calculation formula is pre-stored, and a descending-type PID control unit in which a torque decrease calculation formula is pre-stored, When the slip ratio exceeds the preset slip critical value, the control unit triggers the PID control module and selectively uses the ascending PID control unit or the descending PID control unit to adjust the output torque based on the magnitude of the slip ratio. Vehicle slip dynamic control system.

2. The torque increase calculation formula is Yn=Rising_P*ΔXn+Rising_I*ΣΔXn+Rising_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Rising_P*ΔXn is the calculation of the proportional control amount, Rising_I*ΣΔXn is the calculation of the integral control amount, and Rising_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and the output torque Yn is obtained by adding these control amounts.

10. The vehicle slip dynamic control system of claim 1.

3. The torque decrease calculation formula is Yn=Falling_P*ΔXn+Falling_I*ΣΔXn+Falling_D*(ΔXn-ΔX(n-1)), where ΔXn is the calculation of the current control error value, Falling_P*ΔXn is the calculation of the proportional control amount, Falling_I*ΣΔXn is the calculation of the integral control amount, and Falling_D*(ΔXn-ΔX(n-1)) is the calculation of the differential control amount, and the output torque Yn is obtained by adding up these control amounts.

10. The vehicle slip dynamic control system of claim 1.

4. The slip ratio is calculated by the formula: slip ratio = front wheel speed / rear wheel speed. When the slip ratio exceeds the preset slip threshold, the PID control module is triggered to operate.

10. The vehicle slip dynamic control system of claim 1.

5. The control unit further includes calculating a slip compensation value using a formula, where the slip compensation value = torque * slip value.

10. The vehicle slip dynamic control system of claim 1.

6. measuring front wheel speed and rear wheel speed; calculating a slip ratio after receiving the front wheel speed and the rear wheel speed by a control unit; determining whether the slip ratio exceeds a preset slip critical value; and if the slip ratio exceeds the preset slip critical value, selectively using an ascending PID control unit or a descending PID control unit based on the slip ratio to adjust the output torque. A method for implementing a vehicle slip power control system.

7. When the rising PID control unit operates, the process includes the steps of calculating a current control error ΔXn, calculating a proportional control amount Rising_P*ΔXn, calculating an integral control amount Rising_I*ΣΔXn, calculating a differential control amount Rising_D*(ΔXn-ΔX(n-1)), and adding these control amounts to obtain an output torque Yn.

7. A method for implementing a vehicle slip dynamics control system as set forth in claim 6.

8. When the descending PID control unit operates, the process includes the steps of: calculating a current control error ΔXn; calculating a proportional control amount Falling_P*ΔXn; calculating an integral control amount Falling_I*ΣΔXn; calculating a differential control amount Falling_D*(ΔXn-ΔX(n-1)); and adding these control amounts to obtain an output torque Yn.

7. A method for implementing a vehicle slip dynamics control system as set forth in claim 6.

9. The calculation step for calculating the slip ratio includes: slip ratio = front wheel speed / rear wheel speed. If the slip ratio exceeds the preset slip critical value, the PID control module is triggered to operate.

7. A method for implementing a vehicle slip dynamics control system as set forth in claim 6.

10. The control unit further includes calculating a slip compensation value using a formula, where the slip compensation value = torque * slip value.

7. A method for implementing a vehicle slip dynamics control system as set forth in claim 6.

Images