A traction control system for two-wheeled motorcycles

Abstract

This invention provides a traction control system for a two-wheeled motorcycle, including wheel speed sensors, an anti-lock braking system (ABS), a traction control system, an engine electronic fuel injection (EFI) system, and an EFI drive system. The wheel speed sensors collect the rotation frequencies of the front and rear wheels, calculate the wheel speeds and the vehicle speed, and calculate the slip ratio using the vehicle speed and rear wheel speed. The traction control system outputs a target control torque signal based on the slip ratio and sends it to the engine EFI system. The engine EFI system outputs control commands to the EFI drive system, which in turn outputs torque to the drive wheels to propel the motorcycle. This invention assesses wheel slip by collecting the rotation frequencies of the front and rear wheels to calculate the slip ratio, and then intervenes in the traction control system to determine whether to reduce engine torque. This ensures that the motorcycle remains stable during high-throttle starts or acceleration on slippery surfaces, suppressing slippage.

Description

Technical Field

[0001] This invention relates to the field of motorcycle control technology, and more specifically, to a traction control system for a two-wheeled motorcycle. Background Technology

[0002] With the development of technology, people's travel has become increasingly convenient. Among them, two-wheeled motorcycles, due to their small size and high maneuverability, are becoming more and more popular in the market. However, two-wheeled motorcycles have poor stability. When the vehicle is driving or braking, the wheels are prone to slipping or locking up, which reduces the stability of the vehicle and increases the risk of crashes. In particular, large-displacement (250cc) motorcycles are very prone to wheel slippage or even fishtailing when starting or accelerating on wet or slippery roads due to insufficient ground adhesion.

[0003] To suppress the aforementioned phenomena and reduce the risk of crashes, it is necessary to reduce the engine's output torque as quickly as possible when the drive wheels slip, thereby reducing the speed of the drive wheels and ensuring vehicle stability. Traction control systems, as an active safety feature, are now widely used in four-wheeled vehicles, but their adoption rate in two-wheeled motorcycles remains low, and the traction systems of four-wheeled vehicles cannot be directly applied to two-wheeled motorcycles. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a traction control system for two-wheeled motorcycles, which solves the problem of motorcycle instability when starting or accelerating at high throttle on wet and slippery roads in the prior art.

[0005] The technical solution adopted by this invention to solve the above problems is as follows: a two-wheeled motorcycle traction control system, including a wheel speed sensor, an anti-lock braking system, a traction control system, an engine electronic fuel injection and control system, and an electronic fuel injection drive system. The wheel speed sensor collects the rotation frequency of the front and rear wheels, calculates the wheel speeds of the front and rear wheels and the vehicle speed, and calculates the slip ratio reflecting the degree of slippage of the drive wheels using the vehicle speed and rear wheel speed. The traction control system outputs a target control torque signal based on the magnitude of the slip ratio using a PID control algorithm and sends it to the engine electronic fuel injection and control system. The engine electronic fuel injection and control system outputs control commands to the electronic fuel injection drive system. The electronic fuel injection drive system outputs torque to the drive wheels to drive the motorcycle. Wherein, slip ratio = (vehicle speed - rear wheel speed) / vehicle speed.

[0006] Compared with the prior art, the advantages of the present invention are: by collecting the wheel speed information of the front and rear wheels to calculate the slip ratio to assess whether the wheels are slipping, and then determining whether it is necessary to intervene in the traction control system to control the engine to reduce torque, so that the two-wheeled motorcycle can always maintain stability when starting or accelerating at high throttle on wet and slippery roads, thus suppressing slippage.

[0007] Preferably, the traction control system activation steps are as follows: First, determine whether the slip ratio is less than the target slip ratio threshold. If so, start the filter counter to accumulate. When the count value of the filter counter is greater than the counting filter threshold, and the target wheel speed deviation is greater than the set wheel speed deviation threshold, the traction control system is activated; otherwise, the traction control system remains in its original state. Wherein, target wheel speed deviation = rear wheel speed - target wheel speed = rear wheel speed - vehicle speed × (1 - target slip ratio). This ensures that the traction control system can intervene when slippage is detected, and after intervention, the engine torque is reduced without causing significant surging or driver discomfort.

[0008] Preferably, the traction control system must meet all of the following conditions to be activated: the throttle enable position is open; the traction control system is not activated; the drive mode is not in the off state; and the traction control system is fault-free. This ensures that the traction control system can intervene and successfully start later.

[0009] Preferably, the traction control system calculates the target wheel speed by setting a target slip ratio, and adjusts the drive wheel control torque using a PID control algorithm to ultimately control the drive wheel speed within the target wheel speed range. In this way, through PID control, proportional control enables the engine to quickly reduce torque, integral control reduces torque overshoot, achieving stable control, and derivative control gradually stabilizes the control trend.

[0010] Preferably, the traction control system's control algorithm is integrated into the electronic control unit of the anti-lock braking system (ABS), sharing wheel speed sensor signals and vehicle dynamic signals with the ABS. This integration of the traction control system into the ABS, along with the shared wheel speed sensors, reduces the cost of the controller and sensors.

[0011] Preferably, the traction control system interacts with the engine's electronic fuel injection system via CAN network communication, receiving signals such as the engine's current torque, the driver's required torque, engine speed, and throttle opening. This interaction with the electronic fuel injection control system via CAN network technology, coupled with the CAN network security mechanism, enhances the security and real-time performance of information exchange.

[0012] Preferably, the engine electronic fuel injection and control system, based on the target torque signal and traction intervention control status signal transmitted by the traction control system, adjusts the ignition angle to respond to changes in the target torque. When the reduction in target torque exceeds a set reduction value or falls below a set target torque value, the engine electronic fuel injection and control system will use fuel cut-off to rapidly reduce torque. Thus, when the motorcycle slips, the engine electronic fuel injection and control system can send a torque change signal to reduce engine torque.

[0013] Preferably, the vehicle speed calculation steps are as follows: If anti-lock braking system (ABS) control is activated, first set the initial vehicle speed descent slope, then determine whether it is single-axle ABS control. If not, adjust the descent slope according to the deceleration control mode, and the vehicle speed decreases at a fixed descent slope, taking the maximum value of the front and rear wheel speeds. If yes, determine whether it is single-axle front wheel ABS control or single-axle rear wheel ABS control. If it is single-axle front wheel ABS control, the vehicle speed decreases at a fixed descent slope close to the rear wheel speed, taking the maximum value of the front and rear wheel speeds. If it is single-axle rear wheel ABS control, the vehicle speed decreases at a fixed descent slope close to the front wheel speed, taking the maximum value of the front and rear wheel speeds. If anti-lock braking system control is not activated, first determine the vehicle speed. If the vehicle speed is less than the minimum value of the front and rear wheel speeds, the vehicle speed increases at a fixed increase slope, taking the maximum value of the front and rear wheel speeds; otherwise, take the current vehicle speed. If the vehicle speed is greater than the maximum value of the front and rear wheel speeds, the vehicle speed decreases at a fixed descent slope, taking the maximum value of the front and rear wheel speeds; otherwise, take the current vehicle speed. Attached Figure Description

[0014] Figure 1 This is a system block diagram of a two-wheeled motorcycle traction control system according to the present invention;

[0015] Figure 2 This is a flowchart illustrating the startup process of a traction control system for a two-wheeled motorcycle according to the present invention.

[0016] Figure 3 This is a PID control flowchart of a two-wheeled motorcycle traction control system according to the present invention;

[0017] Figure 4 This is a flowchart illustrating the speed calculation process of a two-wheeled motorcycle traction control system according to the present invention. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] like Figure 1-4As shown, this embodiment relates to a traction control system for a two-wheeled motorcycle, including wheel speed sensors, an anti-lock braking system, a traction control system, an engine electronic fuel injection and control system, and an electronic fuel injection drive system. The wheel speed sensors collect the rotation frequencies of the front and rear wheels and calculate the wheel speeds of the front and rear wheels and the vehicle speed through an algorithm. The slip ratio, which reflects the degree of slippage of the drive wheels, is calculated from the vehicle speed and the rear wheel speed. The traction control system outputs a target control torque signal based on the magnitude of the slip ratio using a PID control algorithm and sends it to the engine electronic fuel injection and control system. The engine electronic fuel injection and control system outputs control commands to the electronic fuel injection drive system. The electronic fuel injection drive system outputs torque to the drive wheels to drive the motorcycle.

[0020] The slip ratio is calculated as (vehicle speed - rear wheel speed) / vehicle speed. The electronic fuel injection drive system is the same as the ignition control system for a gasoline engine.

[0021] The purpose of the traction control system is to keep the slip rate of the motorcycle's drive wheels within a stable range. (See also...) Figure 2 As shown, the starting steps of the traction control system are as follows: First, determine whether the slip ratio is less than the target slip ratio threshold. If so, start the filter counter to accumulate. When the count value of the filter counter is greater than the counting filter threshold, and at the same time the target wheel speed deviation is greater than the set wheel speed deviation threshold, the traction control system starts. Otherwise, the traction control system remains in its original state.

[0022] The target slip ratio is calculated by the target slip ratio module. This module first sets an initial value for the target slip ratio, then comprehensively calculates the target slip ratio based on factors such as ground adhesion coefficient correction, driving condition correction, and whether there is a rough road condition correction, before outputting the target slip ratio. The target slip ratio module then sets a target slip ratio threshold based on the output target slip ratio.

[0023] The counting filter threshold is set by the filtering module. The filtering module first sets an initial value for the counting filter threshold, and then adjusts it according to driving conditions. The filter counter is mainly used for delay to ensure the stability of the current slip ratio data. The initial value of the counting filter threshold is 0.02 seconds.

[0024] The target wheel speed deviation is calculated as follows: Target wheel speed = Rear wheel speed - Target wheel speed = Rear wheel speed - Vehicle speed × (1 - Target slip ratio). The target wheel speed is calculated based on the vehicle speed and the target slip ratio. The wheel speed deviation threshold is set manually, and the current setting is 0.4. If the target wheel speed deviation is greater than 0, the drive wheel speed exceeds the stable range, requiring torque reduction; if the target wheel speed deviation is less than 0, the drive wheel speed is below the stable range, allowing for appropriate torque increase.

[0025] This setup ensures that the traction control system can intervene when slippage is detected. After the traction control system intervenes and reduces engine torque, there will be no significant surging sensation, thus preventing driver discomfort.

[0026] The traction control system requires all of the following conditions to be met before it can be activated: the throttle enable position is open; the traction control system is not activated; the drive mode is not off; and the traction control system is functioning correctly. This ensures that the traction control system can intervene and activate successfully later.

[0027] The traction control system calculates the target wheel speed by setting a target slip ratio, and adjusts the control torque of the drive wheels using a PID control algorithm to keep the final drive wheel speed within the target range. Through PID control, proportional (P) control enables the engine to quickly reduce torque, integral (I) control reduces torque overshoot, achieving stable control, and derivative (D) control gradually stabilizes the control trend.

[0028] See Figure 3 As shown, the PID control algorithm is as follows:

[0029] First, calculate the PID coefficients.

[0030] For the proportional P coefficient, first calibrate the initial value of the P coefficient, and then determine whether the target wheel speed deviation is greater than the correction upper limit. If so, it means that the drive wheel speed is about to exceed the stability limit of the vehicle body. The P coefficient is then amplified and corrected according to the speed to achieve faster torque reduction. Otherwise, no P coefficient compensation correction is performed.

[0031] For the integral I coefficient, first, the initial values ​​of the I coefficient and the I gain compensation value are calibrated. Then, it is determined whether the target wheel speed deviation is greater than zero. If so, the road surface is identified as slippery, and the I gain compensation value is cumulatively reduced based on the inertial torque. If not, it is first determined whether the wheel speed meets the rapid correction condition. If so, the initial value of the I gain compensation value is reset to zero. If not, the road surface is identified as high-adhesion, and the initial value of the I gain compensation value is cumulatively increased. Finally, it is determined whether the I gain compensation value is greater than zero. If so, the I coefficient is increased and compensated based on the I gain compensation value; otherwise, no I coefficient compensation correction is performed.

[0032] The fast correction condition is that the motorcycle's acceleration is greater than 2 m / s², and the target wheel speed deviation remains less than 0 for 30 calculation cycles (20 ms). The purpose of fast correction is to address the issue of excessive wheel slippage on wet surfaces, where the gain compensation value continuously decreases to a negative value, thus omitting I-coefficient compensation. When returning from a wet surface to a high-traction surface, the current driving torque is insufficient, and the target wheel speed deviation is less than 0. Therefore, the gain compensation needs to quickly return to a positive value and then continuously accumulate to increase the I-coefficient.

[0033] For the differential D coefficients, it is only necessary to calibrate the D coefficients.

[0034] Then, calculate the PID target torque M = M_P + M_I + M_D, where the proportional torque M_P = -1 × proportional P coefficient × target wheel speed deviation, the integral torque M_I = integral torque of the previous cycle - integral I coefficient × target wheel speed deviation, and the differential torque M_D = -1 × differential D coefficient × inertial torque.

[0035] When the vehicle is initially powered on and started, the traction control system is not engaged. In this unengaged state, the integral torque M_I is equal to the drive torque at the drive wheels and varies with the drive torque; no integral torque calculation is performed. Integral torque calculation only begins after the traction control system engages, and the integral torque for the first round after engagement is calculated using the current drive torque.

[0036] Next, it determines whether it is in the first round of torque increase / decrease control cycle. If so, the target torque is used directly to achieve rapid torque reduction. If not, it first determines whether a slippery road surface is detected. If not, the target torque is also used directly to achieve rapid torque reduction. If so, the target wheel speed calculation coefficient is reduced first, then the proportional ratio coefficient is reduced, and then it is determined whether the target wheel speed deviation is greater than zero. If not, the target torque is used directly to achieve rapid torque reduction. If so, the target torque with the minimum proportional torque ratio is used to make the target torque increase slowly.

[0037] The specific calculations for the target wheel speed and target torque after reducing the target wheel speed calculation coefficient and then further reducing the proportional coefficient are as follows:

[0038] For non-slippery surfaces: target wheel speed = vehicle speed × (1 - target slip ratio), target torque = calculated PID target torque M + proportional torque × proportion coefficient; For slippery surfaces: target wheel speed = vehicle speed × reduction coefficient × (1 - target slip ratio), target torque = calculated PID target torque M + proportional torque × reduced proportion coefficient.

[0039] The PID control algorithm described above can be used to adjust the target torque, thereby adjusting the control torque of the drive wheels and ultimately controlling the drive wheel speed within the target wheel speed range.

[0040] The traction control system's control algorithm is integrated into the electronic control unit of the anti-lock braking system (ABS), sharing wheel speed sensor signals and vehicle dynamic signals with the ABS. This integration of the traction control system into the ABS, along with the shared wheel speed sensors, reduces the cost of controllers and sensors.

[0041] The traction control system communicates with the engine's electronic fuel injection system via a CAN network, receiving signals such as the engine's current torque, the driver's required torque, engine speed, and throttle opening. This interaction with the electronic fuel injection control system via CAN network technology, coupled with the CAN network security mechanism, enhances the security and real-time performance of information exchange.

[0042] The engine's electronic fuel injection and control system, based on the target torque signal and traction intervention control status signal transmitted from the traction control system, adjusts the ignition timing to respond to changes in the target torque. When the reduction in target torque exceeds a set reduction value or falls below a set target torque value, the system cuts off fuel to rapidly reduce torque. Thus, when the motorcycle slips, the electronic fuel injection and control system can send torque change signals to reduce engine torque.

[0043] See Figure 4 As shown, the steps for calculating vehicle speed are as follows:

[0044] If anti-lock braking system (ABS) control is activated, first set the initial speed reduction slope, then determine whether it is single-axle ABS control. If not, adjust the reduction slope according to the deceleration control mode, and the vehicle speed decreases at a fixed slope, taking the maximum value of the front and rear wheel speeds. If yes, determine whether it is single-axle front or rear ABS control. If it is single-axle front ABS control, the vehicle speed decreases at a fixed slope close to the rear wheel speed, taking the maximum value of the front and rear wheel speeds. If it is single-axle rear ABS control, the vehicle speed decreases at a fixed slope close to the front wheel speed, taking the maximum value of the front and rear wheel speeds.

[0045] If the anti-lock braking system is not activated, the vehicle speed is first assessed. If the vehicle speed is less than the minimum speed of the front and rear wheels, the vehicle speed increases at a fixed upward slope and the maximum speed of the front and rear wheels is taken; otherwise, the current vehicle speed is taken. If the vehicle speed is greater than the maximum speed of the front and rear wheels, the vehicle speed decreases at a fixed downward slope and the maximum speed of the front and rear wheels is taken; otherwise, the current vehicle speed is taken.

[0046] This allows for a more accurate calculation of vehicle speed.

[0047] In this embodiment, during the intervention of the traction control system, an indicator light will flash to remind the driver that the road surface is slippery and that caution is required.

[0048] The beneficial effects of this invention are as follows: by collecting the rotation frequency of the front and rear wheels to calculate the slip rate, the system assesses whether the wheels are slipping. Then, by intervening in the traction control system to determine whether to reduce engine torque, the system identifies the road surface condition and adjusts the control parameters during the control process. This ensures that the two-wheeled motorcycle can always maintain stability when starting or accelerating at high throttle on wet and slippery roads, thus suppressing slippage.

[0049] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

[0050] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A traction control system for a two-wheeled motorcycle, characterized in that: It includes wheel speed sensors, anti-lock braking system, traction control system, engine electronic fuel injection and control system, and electronic fuel injection drive system. The wheel speed sensors collect the rotation frequency of the front and rear wheels, calculate the wheel speed of the front and rear wheels and the vehicle speed. The slip ratio, which reflects the degree of slippage of the drive wheels, is calculated from the vehicle speed and the rear wheel speed. The traction control system outputs the target control torque signal based on the magnitude of the slip ratio using a PID control algorithm and sends it to the engine electronic fuel injection and control system. The engine's electronic fuel injection and control system outputs control commands to the electronic fuel injection drive system; the electronic fuel injection drive system outputs torque to the drive wheels to drive the motorcycle's movement. Wherein, slip ratio = (vehicle speed - rear wheel speed) / vehicle speed; The steps for calculating vehicle speed are as follows: If anti-lock braking system (ABS) control is activated, first set the initial speed reduction slope, then determine whether it is single-axle ABS control. If not, adjust the reduction slope according to the deceleration control mode, and the vehicle speed decreases at a fixed slope, taking the maximum value of the front and rear wheel speeds. If yes, determine whether it is single-axle front or rear ABS control. If it is single-axle front ABS control, the vehicle speed decreases at a fixed slope close to the rear wheel speed, taking the maximum value of the front and rear wheel speeds. If it is single-axle rear ABS control, the vehicle speed decreases at a fixed slope close to the front wheel speed, taking the maximum value of the front and rear wheel speeds. If the anti-lock braking system is not activated, the vehicle speed is first assessed. If the vehicle speed is less than the minimum speed of the front and rear wheels, the vehicle speed increases at a fixed upward slope and the maximum speed of the front and rear wheels is taken; otherwise, the current vehicle speed is taken. If the vehicle speed is greater than the maximum speed of the front and rear wheels, the vehicle speed decreases at a fixed downward slope and the maximum speed of the front and rear wheels is taken; otherwise, the current vehicle speed is taken.

2. The traction control system for a two-wheeled motorcycle according to claim 1, characterized in that: The traction control system startup steps are as follows: First, determine whether the slip ratio is less than the target slip ratio threshold. If so, start the filter counter to accumulate. When the count value of the filter counter is greater than the counting filter threshold, and the target wheel speed deviation is greater than the set wheel speed deviation threshold, the traction control system is activated. Otherwise, the traction control system remains in its original state. Wherein, target wheel speed deviation = rear wheel speed - target wheel speed = rear wheel speed - vehicle speed × (1 - target slip ratio).

3. The traction control system for a two-wheeled motorcycle according to claim 2, characterized in that: The traction control system must meet all of the following conditions to be activated: the throttle enable position is open; the traction control system is not activated; the drive mode is not in the off state; and the traction control system is fault-free.

4. A traction control system for a two-wheeled motorcycle according to claim 2, characterized in that: The traction control system calculates the target wheel speed by setting a target slip ratio, and adjusts the control torque of the drive wheel through a PID control algorithm to keep the final drive wheel speed within the target wheel speed range.

5. A traction control system for a two-wheeled motorcycle according to claim 1, characterized in that: The traction control system's control algorithm is integrated into the electronic control of the anti-lock braking system, and shares wheel speed sensor signals and vehicle dynamic signals with the anti-lock braking system.

6. A traction control system for a two-wheeled motorcycle according to claim 1, characterized in that: The traction control system communicates with the engine electronic fuel injection and control system via CAN network and receives the engine's current torque signal, the driver's required torque signal, the engine speed signal, and the throttle opening signal.

7. A traction control system for a two-wheeled motorcycle according to claim 1, characterized in that: The engine electronic fuel injection and control system, based on the target torque signal and traction intervention control status signal transmitted by the traction control system, adjusts the ignition angle to change with the target torque of the traction control system after the status is enabled. When the reduction of the target torque is greater than the reduction range set value or the target torque value is less than the target torque set value, the engine electronic fuel injection and control system will use fuel cut-off to achieve rapid torque reduction.

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