Single-channel ABS vehicle speed calculation method and device

Abstract

The application provides a single-channel ABS vehicle speed calculation method and device, only one wheel speed sensor signal is acquired, vehicle speed calculation can be performed, sensor cost is reduced, and cost reduction of products is realized. Based on single-wheel-speed vehicle speed algorithm development, fault alarm caused by two-wheel or one-wheel speed signal abnormality is reduced. Further, electronic components of hardware are reduced, overall ECU layout is reduced, product miniaturization is realized, hydraulic control circuit is reduced, small displacement vehicle models are developed, small motors can be selected, the volume of the hydraulic control unit is reduced, and product light weight is realized. The single-channel ABS is used for controlling the hydraulic system of the front wheel, the maximum braking performance of the disc brake is exerted, and the deceleration generated by the front brake is twice that of the rear brake in the braking process. The scheme allows low-price two-wheel vehicles to be equipped with ABS, and greatly improves the safety of two-wheel vehicles in emergency braking.

Description

Technical Field

[0001] This invention relates to the field of computer technology, and more specifically, to a method and apparatus for calculating vehicle speed using a single-channel ABS system. Background Technology

[0002] With the recovery of the motorcycle market and technological advancements, the installation of anti-lock braking systems (ABS) on two-wheeled motorcycles has become increasingly common. Initially, it was only installed on large-displacement (250cc and above) motorcycles, but now it has been extended to small-displacement (150cc and below) models, and is expected to become a standard safety feature for two-wheeled motorcycles in the future.

[0003] Currently, most motorcycle ABS products on the market use dual wheel speed sensors and a dual-channel hydraulic control unit. This makes it difficult to achieve widespread adoption in low-end models, and they are generally only installed in high-end or high-spec models. Existing solutions require two wheel speed sensors to acquire wheel speed signals from the front and rear wheels. Based on a vehicle speed algorithm, the system estimates the vehicle's speed during braking to determine the slip ratio of the front or rear wheel. This slip ratio is then used to control the hydraulic control unit (HCU), stabilizing the braking force within a reasonable pressure range and ultimately ensuring stable braking until the vehicle comes to a stop. Dual-channel ABS requires controlling the hydraulic pressure of both the front and rear wheels, thus necessitating two wheel speed sensors and two valve control circuits.

[0004] The drawback of the above solution is that the vehicle speed algorithm of the dual-channel ABS is calculated based on the front and rear wheel speed signals. The stability and accuracy of the vehicle speed signals are greatly affected by the front and rear wheel speeds. When one of the wheel speed sensors malfunctions, such as signal loss due to connector damage, signal protrusion due to wheel speed gear ring damage, or wheel speed deviation due to wheel size changes, the wheel speed will fail, the dual-channel ABS function will report a fault, and the entire ABS function will fail.

[0005] Therefore, how to provide a vehicle speed calculation method with higher adaptability, stability, and accuracy is an urgent problem to be solved. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a single-channel ABS vehicle speed calculation method and apparatus.

[0007] A first aspect of the present invention provides a method for calculating vehicle speed using a single-channel ABS system, the method comprising: A wheel speed square wave signal is obtained by a wheel speed sensor installed on the front wheel of the motorcycle, and the corresponding wheel speed is calculated based on the wheel speed square wave signal. Delay correction for wheel speed; The vehicle speed is increased or decreased based on the corrected wheel speed; Calculate the value of the increase or decrease in vehicle speed; Correct the vehicle deceleration value and calculate the vehicle speed.

[0008] Optionally, the step of delaying the wheel speed correction specifically includes: Determine whether the deviation between the wheel speed variable in the current detection cycle and the wheel speed variable in the previous detection cycle is less than a preset first threshold. If so, the wheel speed variable in the previous detection cycle remains at its current value. If not, determine whether the wheel speed variable of the current detection cycle is less than the wheel speed variable of the previous detection cycle. If yes, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope. If no, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope.

[0009] Optionally, when the vehicle is in a non-ABS control state, the rising variable value is a fixed value; when the vehicle is in the early stage of ABS control, the falling variable value is calculated as follows: Determine whether the vehicle deceleration is less than a preset second threshold; If so, the value of the decrease in vehicle speed is twice the vehicle deceleration. If not, determine the front wheel deceleration and, based on the front wheel deceleration value, determine the value of the descent variable.

[0010] Optionally, when the vehicle is under ABS control, the step of calculating the increase or decrease of the vehicle speed variable value specifically includes: When entering the first detection cycle of ABS control, it is determined whether the front wheel deceleration is less than the preset third threshold. If it is, the change in vehicle speed is 0.5 times the vehicle deceleration value. If not, the change in vehicle speed is the vehicle deceleration value. When entering the eighth detection cycle of ABS control, it is determined whether the maximum slip ratio of the vehicle is greater than the preset fourth threshold. If so, the change in vehicle speed is a preset fixed change. If not, the change in vehicle speed is 0.8 times the vehicle deceleration value.

[0011] Optionally, the step of calculating the increasing or decreasing value of the vehicle speed variable further includes: Obtain the peak wheel speed; Calculate the slope between the two peak wheel speed points; The calculated slope is used as the change in vehicle speed after the next wheel speed peak point.

[0012] Optionally, the step of calculating the increasing or decreasing value of the vehicle speed variable further includes: Determine if the calculated slope value is usable. If not, the change in vehicle speed is the vehicle deceleration value. If so, the calculated slope is corrected, and the corrected slope is used as the change in vehicle speed after the next wheel speed peak point.

[0013] Optionally, the step of correcting the calculated slope specifically includes: The slope between two wheel speed peaks is corrected based on wheel speed and road surface characteristics; Determine whether the road surface characteristics meet the characteristics of a high-adhesion road condition. If so, limit the slope value to a preset fifth threshold range. If not, use the slope as the change in vehicle speed.

[0014] Optionally, the step of calculating the vehicle speed specifically includes: Multiply the decrease variable value by the length of the detection period to obtain the vehicle speed change in each period; Determine whether the vehicle speed variable is greater than the wheel speed variable in the current detection cycle. If so, the vehicle speed changes according to the calculated vehicle speed change amount, and cannot be less than the wheel speed. If not, further determine whether the vehicle speed variable is less than the wheel speed variable in the previous detection cycle. If so, the vehicle speed changes according to a preset positive fixed wheel speed change amount, and cannot be greater than the wheel speed variable in the previous detection cycle.

[0015] Optionally, the step of calculating the vehicle speed further includes: Vehicle speed deviation is detected, and if a deviation in the vehicle speed curve is detected, the slope is reduced or increased by a certain coefficient.

[0016] A second aspect of the present invention provides an ABS vehicle speed calculation device, the device comprising: The wheel speed detection unit is used to obtain a wheel speed square wave signal through a wheel speed sensor installed on the front wheel of the motorcycle, and to calculate the corresponding wheel speed based on the wheel speed square wave signal. Wheel speed correction unit, used for delay correction of wheel speed; The rise and fall statistics unit is used to determine whether the vehicle speed is rising or falling based on the corrected wheel speed; The change calculation unit is used to calculate the increase or decrease of vehicle speed. The vehicle speed calculation unit is used to correct the vehicle deceleration value and calculate the vehicle speed.

[0017] A third aspect of the present invention provides an electronic device, characterized in that it comprises: One or more processors; memory; one or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, and the one or more applications are configured to perform the method as described in the first aspect.

[0018] A fourth aspect of the present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores program code that can be invoked by a processor to execute the method described in the first aspect.

[0019] In summary, this invention provides a single-channel ABS vehicle speed calculation method and device. It calculates vehicle speed by acquiring only one wheel speed sensor signal, reducing sensor costs and achieving cost reduction. The single-wheel speed algorithm reduces fault alarms caused by abnormal square wave signals from two or one wheel. This further reduces the number of electronic components in the hardware, shrinks the overall ECU layout, and achieves product miniaturization. It also reduces hydraulic control circuits, allowing for the use of smaller motors for small-displacement vehicles, reducing the size of the hydraulic control unit and achieving product lightweighting. The single-channel ABS controls the front wheel hydraulic system, maximizing the braking performance of the disc brakes. During braking, the deceleration generated by the front brake is twice that of the rear brake. This solution allows even low-priced two-wheeled vehicles to be equipped with ABS, greatly improving the safety of two-wheeled vehicles during emergency braking. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of the single-channel ABS vehicle speed calculation method according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the selection of the wheel speed peak point according to an embodiment of the present invention; Figure 3 A schematic diagram illustrating the situation where slope correction is required in an embodiment of the present invention; Figure 4 This is a schematic diagram illustrating the effect of speed deviation recognition and correction according to an embodiment of the present invention; Figure 5 This is a functional block diagram of the ABS vehicle speed calculation device according to an embodiment of the present invention; Figure 6This is a structural block diagram of an electronic device for executing a single-channel ABS vehicle speed calculation method according to an embodiment of the present invention.

[0022] Figure 7 This is a structural block diagram of a computer-readable storage medium for storing or carrying program code implementing the single-channel ABS vehicle speed calculation method according to an embodiment of the present invention.

[0023] icon: Wheel speed detection unit 110; wheel speed correction unit 120; rise and fall statistics unit 130; change calculation unit 140; vehicle speed calculation unit 150; electronic equipment 300; processor 310; memory 320; computer-readable storage medium 400; program code 410. Detailed Implementation

[0024] With the recovery of the motorcycle market and technological advancements, the installation of anti-lock braking systems (ABS) on two-wheeled motorcycles has become increasingly common. Initially, it was only installed on large-displacement (250cc and above) motorcycles, but now it has been extended to small-displacement (150cc and below) models, and is expected to become a standard safety feature for two-wheeled motorcycles in the future.

[0025] Currently, most motorcycle ABS products on the market use dual wheel speed sensors and a dual-channel hydraulic control unit. This makes it difficult to achieve widespread adoption in low-end models, and they are generally only installed in high-end or high-spec models. Existing solutions require two wheel speed sensors to acquire wheel speed signals from the front and rear wheels. Based on a vehicle speed algorithm, the system estimates the vehicle's speed during braking to determine the slip ratio of the front or rear wheel. This slip ratio is then used to control the hydraulic control unit (HCU), stabilizing the braking force within a reasonable pressure range and ultimately ensuring stable braking until the vehicle comes to a stop. Dual-channel ABS requires controlling the hydraulic pressure of both the front and rear wheels, thus necessitating two wheel speed sensors and two valve control circuits.

[0026] The drawback of the above solution is that the vehicle speed algorithm of the dual-channel ABS is calculated based on the front and rear wheel speed signals. The stability and accuracy of the vehicle speed signals are greatly affected by the front and rear wheel speeds. When one of the wheel speed sensors malfunctions, such as signal loss due to connector damage, signal protrusion due to wheel speed gear ring damage, or wheel speed deviation due to wheel size changes, the wheel speed will fail, the dual-channel ABS function will report a fault, and the entire ABS function will fail.

[0027] Therefore, how to provide a vehicle speed calculation method with higher adaptability, stability, and accuracy is an urgent problem to be solved.

[0028] In view of this, the inventors of this invention have designed a single-channel ABS vehicle speed calculation method and device. By acquiring a single wheel speed sensor signal, vehicle speed can be calculated, reducing sensor costs and achieving cost reduction. The vehicle speed algorithm based on single wheel speed reduces fault alarms caused by abnormal square wave signals from two or one wheel. This further reduces the number of electronic components in the hardware, shrinks the overall ECU layout, and achieves product miniaturization. It also reduces hydraulic control circuits, allowing for the use of smaller motors for small-displacement vehicles, reducing the size of the hydraulic control unit and achieving product lightweighting. The single-channel ABS is used to control the hydraulic system of the front wheels, maximizing the braking performance of the disc brakes. During braking, the deceleration generated by the front brake is twice that of the rear brake. This solution allows even low-priced two-wheeled vehicles to be equipped with ABS, greatly improving the safety of two-wheeled vehicles during emergency braking.

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of this invention, it should be noted that the terms "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. Example

[0035] This embodiment provides a single-channel ABS vehicle speed calculation method and device, applied to motorcycles equipped with an ABS anti-lock braking system. The main working principle of the ABS anti-lock braking system is as follows: front and rear wheel speed sensors detect wheel speed square wave signals, which are input to the electronic control unit (ECU). The ECU calculates the vehicle slip ratio. When a tendency for the wheels to lock up is detected, it indicates excessive braking force. The ECU outputs a control signal to the solenoid valve, which reduces the wheel cylinder pressure by opening and closing the valve. When the pressure drops too low, the wheel speed increases, and the controller calculates a decrease in the slip ratio. It then adjusts the wheel cylinder pressure by controlling the solenoid valve. The ABS controller, through the hydraulic control unit, adjusts the wheel cylinder braking pressure to prevent wheel lock-up and keeps the wheels near the optimal slip ratio, maintaining optimal braking performance. Motorcycle ABS has the following functions: improving lateral stability during braking, improving directional maneuverability during braking, and improving braking efficiency.

[0036] ABS braking control is a closed-loop control system. The input for motorcycle braking is the rider gripping the handbrake, which generates hydraulic pressure in the master cylinder. This hydraulic pressure, after passing through the ABS hydraulic module, acts on the calipers. The entire ABS system has only one input signal: the wheel speed sensor. The wheel speed sensor is mounted on the front wheel and obtains an analog signal corresponding to changes in wheel speed. The wheel, as the controlled object, decelerates under the action of the calipers during braking. The calipers are hydraulically driven. In non-ABS control mode, the handbrake force acts directly on the calipers. In ABS mode, the handbrake force is processed by the ABS system, outputting a force that effectively prevents wheel lock-up. Whether ABS activates depends on the slip ratio calculated from the wheel speed and vehicle speed. When the slip ratio exceeds the ABS threshold, the wheels tend to lock up, the vehicle becomes unstable, and ABS activates to control the braking force. The direct object of control is the valve in the ABS hydraulic control unit (HCU). The opening and closing of the valve effectively controls the hydraulic pressure acting on the calipers, thereby controlling the wheel speed.

[0037] The execution logic of the ABS algorithm control is as follows: the signal obtained by the wheel speed sensor is an analog square wave signal, and the frequency of the square wave changes according to the vehicle speed. The first step of the ABS algorithm is to convert the analog signal into a wheel speed square wave signal that reflects the vehicle's braking speed. A simple wheel speed square wave signal may have jitter due to signal interference, so it needs to be filtered to obtain a smoother wheel speed square wave signal. Since no sensor is installed to detect the vehicle speed, this signal needs to be calculated by the algorithm based on the wheel speed. With the vehicle speed and wheel speed, the current slip ratio can be calculated. The slip ratio signal can be used to determine the current stability of the vehicle, and the road surface condition that the vehicle may be on can be identified based on the current wheel speed square wave signal, thereby determining whether ABS should be activated for anti-lock braking control. The ABS controller, from the vehicle controller to the axle controller and then to the wheel controller, calculates the accurate control time to achieve the anti-lock control effect. Finally, the control time is converted into the opening and closing commands of the corresponding valves, driving the valve motors, etc., to hydraulically control the brake fluid, keeping the braking force within an effective control range, thereby controlling the wheel-to-ground slip ratio within the optimal range.

[0038] Based on the above, such as Figure 1 As shown, this is a single-channel ABS vehicle speed calculation method provided by an embodiment of the present invention. The basic logic of the vehicle speed algorithm is that, under the single-channel ABS control module, there is only one wheel speed curve as a reference. The change in vehicle speed needs to be adjusted in real time according to the change in wheel speed. The adjustment variable calculated from the wheel speed is then compared with the deceleration value to obtain a more suitable correction parameter, and finally the vehicle speed is calculated.

[0039] Specifically, the method includes: Step S101: Obtain a wheel speed square wave signal by using a wheel speed sensor installed on the front wheel of the motorcycle, and calculate the corresponding wheel speed based on the wheel speed square wave signal.

[0040] Step S102: Perform delay correction on wheel speed; Because wheel speed fluctuates after the speed increases, and the actual vehicle speed lags behind the wheel speed, a delay correction is applied to the wheel speed, and the corrected speed is considered to be the current vehicle speed.

[0041] In a preferred embodiment of the present invention, the step of delaying the wheel speed specifically includes: Determine whether the deviation between the wheel speed variable in the current detection cycle and the wheel speed variable in the previous detection cycle is less than a preset first threshold. If so, the wheel speed variable in the previous detection cycle remains at its current value. If not, determine whether the wheel speed variable of the current detection cycle is less than the wheel speed variable of the previous detection cycle. If yes, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope. If no, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope.

[0042] Preferably, the first threshold value is 0.06.

[0043] The purpose of wheel speed correction is to filter out minor fluctuations in wheel speed data. The filtered wheel speeds are then processed to ensure uninterrupted control. The decrease and increase correction amounts are fixed values ​​under non-ABS control, therefore the curve change of the corrected wheel speed in each cycle is relatively regular. A value less than 0.06 is used to maintain a certain deviation between vehicle speed and wheel speed. For actual vehicle speed and wheel speed, wheel speed is greater than vehicle speed during acceleration and less than vehicle speed during deceleration.

[0044] Step S103: Determine whether the vehicle speed increases or decreases based on the corrected wheel speed; If the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope, it is determined that the vehicle speed is decreasing; if the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope, it is determined that the vehicle speed is increasing.

[0045] Step S104: Calculate the value of the increase or decrease in vehicle speed; In embodiments of the present invention, a suitable calculation method is selected based on whether the system is in ABS control state.

[0046] In a preferred embodiment of the present invention, when the vehicle is in a non-ABS control state, the rising variable value is a fixed value; when the vehicle is in the early stage of ABS control, the falling variable value is calculated as follows: Determine whether the vehicle deceleration is less than a preset second threshold; If so, the value of the decrease in vehicle speed is twice the vehicle deceleration. If not, determine the front wheel deceleration and, based on the front wheel deceleration value, determine the value of the descent variable.

[0047] Specifically, the early stage of ABS control refers to the period when braking begins but the slip ratio has not yet reached the ABS intervention threshold.

[0048] Preferably, the second threshold value is -2.5 m / s^2.

[0049] The deceleration varies around -2.5 m / s², reflecting the current vehicle's operating state. The filtered wheel deceleration reflects the wheel's changing state. The vehicle's operating state cannot be significantly affected by wheel changes; therefore, specific values ​​need to be assigned to the vehicle speed change for different wheel decelerations. The minimum overall change value should not exceed -10. It's important to note that all calculated changes are multiplied by the detection cycle time to obtain the vehicle speed change in each cycle. When the wheel speed is greater than the vehicle speed, the vehicle speed increases towards the wheel speed at a fixed rate. When braking occurs, the wheel speed decreases and becomes less than the vehicle speed. At this point, a suitable downward slope variable is assigned to the vehicle speed based on the current vehicle deceleration and wheel deceleration (i.e., the downward slope is used to approach the wheel speed in each calculation cycle based on the vehicle speed decrease), ensuring the estimated vehicle speed is as close as possible to the actual vehicle speed and guaranteeing effective ABS braking.

[0050] As a preferred embodiment of the present invention, the variable calculation under ABS control mainly consists of three parts: Part 1: Selection of vehicle speed change when ABS is first activated.

[0051] At this time, when the vehicle is under ABS control, the step of calculating the increase or decrease of the vehicle speed variable value specifically includes: When entering the first detection cycle of ABS control, it is determined whether the front wheel deceleration is less than the preset third threshold. If so, the change in vehicle speed is 0.5 times the vehicle deceleration value. If not, the change in vehicle speed is the vehicle deceleration value. Preferably, the third threshold is -60.

[0052] When entering the eighth detection cycle of ABS control, it is determined whether the vehicle's maximum slip ratio is greater than a preset fourth threshold. If so, the change in vehicle speed is a preset fixed change; otherwise, the change in vehicle speed is 0.8 times the vehicle deceleration value. Preferably, the fourth threshold is set to 0.13.

[0053] When ABS is first activated, there are very few signals that can be used as a reference for subsequent vehicle speed changes. At this time, the deceleration is in the state before ABS was activated. The only signal that can be used as a reference and to predict subsequent vehicle speed changes is the wheel deceleration signal. Because the force exerted by braking on the wheels under different road surface adhesion coefficients will cause differences in wheel speed changes, the friction on high-friction surfaces is greater, so the reaction force on braking is also greater, and the wheel speed change may be large, but the effect time is short, and the wheel deceleration will often remain at a low value. On low-friction surfaces, the friction on the ground is smaller, and the wheels will not immediately recover wheel speed even when decelerated. Therefore, on low-friction surfaces, the wheel deceleration value is in a larger range and will last for a longer period of time.

[0054] The initial ABS processing flow is divided into two stages. The first stage is the initial ABS activation, where vehicle speed changes are correlated with the vehicle's deceleration value. The second stage, the 8th detection cycle after activation, assesses the magnitude of wheel deceleration and slip ratio. On high-friction surfaces, wheel deceleration will increase, and the slip ratio is generally small. On low-friction surfaces, wheel deceleration is larger, and the wheel speed change process will continue for some time. Of course, medium-friction surfaces may also trigger the high-friction judgment condition. Therefore, in this section of the process, the correction is limited to -6 to avoid excessive correction. High-friction surfaces may also mistakenly trigger the low-friction judgment, but this does not affect subsequent vehicle speed changes.

[0055] Part Two: Based on the wheel speed vibration, obtain the peak wheel speed and calculate the slope between the two peak wheel speed points as the change in vehicle speed thereafter. Specific steps include: Obtain the peak wheel speed; Calculate the slope between the two peak wheel speed points; The calculated slope is used as the change in vehicle speed after the next wheel speed peak point.

[0056] Selection of wheel speed peak point, such as Figure 2 As shown in the figure, the smoother curve is the corrected wheel speed curve. The variables for rising and falling are fixed, which is helpful for judging the rising and falling conditions. Label 1 is the first wheel speed peak point, and label 2 is the second wheel speed peak point. The slope between the wheel speed peaks of the two points is calculated, and the calculated slope is used as the change in vehicle speed after label 2.

[0057] The step of correcting the calculated slope also includes: The slope between two wheel speed peaks is corrected based on wheel speed and road surface characteristics; The system determines whether the road surface characteristics conform to those of a high-adhesion road condition. If so, the slope value is limited to a preset fifth threshold range; otherwise, the slope is used as the change in vehicle speed. Preferably, the fifth threshold range is set to (-9, -7).

[0058] Part Three: When the peak slope is inappropriate or special road conditions and driving situations occur, deceleration will be applied. The previously calculated peak slope, the coefficient of deceleration, and the minimum value will be selected as the variable for vehicle speed change.

[0059] In a preferred embodiment, after calculating the slope between the two peak wheel speed points, it is necessary to determine whether the calculated slope value is usable. If not, the change in vehicle speed is the vehicle deceleration value. If so, the calculated slope is corrected and the corrected slope is used as the change in vehicle speed after the next peak wheel speed point.

[0060] Specifically, situations requiring slope correction include: Figure 3 As shown in the figure, the slopes calculated from points 1 and 2 are relatively large. When calculating the slopes from points 2 and 3, since the peak values ​​of these two points are approximately at the same location, the resulting slopes are smaller, resulting in a larger difference compared to the slopes calculated from points 1 and 2. This situation will be corrected using deceleration. The speed change after point 3 will be the minimum value between the previously calculated slope and the deceleration, which will be used as the variable.

[0061] Step S105: Correct the vehicle deceleration value and calculate the vehicle speed.

[0062] In a preferred embodiment of the present invention, the step of calculating the vehicle speed specifically includes: Multiply the decrease variable value by the length of the detection period to obtain the vehicle speed change in each period; Determine whether the vehicle speed variable is greater than the wheel speed variable in the current detection cycle. If so, the vehicle speed changes according to the calculated vehicle speed change amount, and cannot be less than the wheel speed. If not, further determine whether the vehicle speed variable is less than the wheel speed variable in the previous detection cycle. If so, the vehicle speed changes according to a preset positive fixed wheel speed change amount, and cannot be greater than the wheel speed variable in the previous detection cycle.

[0063] When the vehicle speed is greater than the wheel speed variable of the upper reference wheel speed curve in the current detection cycle, the vehicle speed decreases according to the real-time calculated change. When it is less than the wheel speed variable of the lower reference wheel speed curve in the previous detection cycle, the vehicle speed increases by a fixed increment. Preferably, this positive fixed wheel speed change is +0.035 m / s / cycle. Typically, each cycle is 5 ms long.

[0064] In a preferred embodiment of the present invention, in order to adjust the vehicle speed in a timely manner when deviation occurs, deviation recognition is incorporated into the vehicle speed calculation. If a deviation in the vehicle speed curve is detected, the slope is reduced or increased by a certain coefficient.

[0065] The specific judgment method includes two aspects, namely: 1. Determine whether the current wheel speed is greater than the vehicle speed and whether the peak wheel speed is greater than 0.1 deviations. If so, further determine whether the vehicle deceleration is greater than -4 and whether the minimum wheel deceleration detected during the wheel speed decrease and increase is less than -10. If both are true, then reduce the slope by a coefficient of 0.8.

[0066] Second, determine whether the current vehicle speed is greater than 0.2 deviations from the peak wheel speed. If so, further determine whether the vehicle deceleration is greater than -4. If so, amplify the slope by a factor of 1.2.

[0067] The effect of correction after vehicle speed deviation detection is as follows: Figure 4 As shown, the curve within the dashed box in the figure deviates downwards. To make the subsequent vehicle speed more realistic, coefficients were added to the variables in the subsequent calculations.

[0068] It should be noted that the above correction process only applies to low-to-medium road conditions and only to changes in vehicle speed correction using deceleration, because this indicates that the estimated deceleration value is already too high and needs to be reduced.

[0069] In summary, the single-channel ABS vehicle speed calculation method provided in this embodiment can calculate vehicle speed by acquiring only one wheel speed sensor signal, reducing sensor costs and achieving product cost reduction. The single-wheel speed-based vehicle speed algorithm reduces fault alarms caused by abnormal square wave signals from two or one wheel. This further reduces the number of electronic components in the hardware, shrinks the overall ECU layout, and achieves product miniaturization. It also reduces hydraulic control circuits, allowing for the use of smaller motors for small-displacement vehicles, reducing the size of the hydraulic control unit and achieving product lightweighting. The single-channel ABS is used to control the hydraulic system of the front wheels, maximizing the braking performance of the disc brakes. During braking, the deceleration generated by the front brake is twice that of the rear brake. This solution allows even low-priced two-wheeled vehicles to be equipped with ABS, greatly improving the safety of two-wheeled vehicles during emergency braking.

[0070] like Figure 5 As shown, the ABS vehicle speed calculation device provided by this invention includes: The wheel speed detection unit 110 is used to obtain a wheel speed square wave signal through a wheel speed sensor installed on the front wheel of the motorcycle, and calculate the corresponding wheel speed based on the wheel speed square wave signal. Wheel speed correction unit 120 is used to perform delay correction on wheel speed; The rise / fall statistics unit 130 is used to determine whether the vehicle speed is rising or falling based on the corrected wheel speed. The change calculation unit 140 is used to calculate the increase or decrease of the vehicle speed. The vehicle speed calculation unit 150 is used to correct the vehicle deceleration value and calculate the vehicle speed.

[0071] The ABS vehicle speed calculation device provided in this embodiment of the invention is used to implement the above-mentioned single-channel ABS vehicle speed calculation method. Therefore, the specific implementation method is the same as the above method, and will not be repeated here.

[0072] like Figure 6The diagram shows a structural block diagram of an electronic device 300 provided in an embodiment of the present invention. This electronic device 300 can be a smartphone, tablet computer, e-reader, or other electronic device capable of running applications. The electronic device 300 in this application may include one or more of the following components: a processor 310, a memory 320, and one or more applications, wherein the one or more applications can be stored in the memory 320 and configured to be executed by one or more processors 310, and the one or more applications are configured to perform the methods described in the foregoing method embodiments.

[0073] Processor 310 may include one or more processing cores. Processor 310 connects to various parts within the electronic device 300 using various interfaces and lines, and performs various functions and processes data of the electronic device 300 by running or executing instructions, programs, code sets, or instruction sets stored in memory 320, and by calling data stored in memory 320. Optionally, processor 310 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 310 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into processor 310 and may be implemented separately using a communication chip.

[0074] The memory 320 may include random access memory (RAM) or read-only memory (ROM). The memory 320 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 320 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), and instructions for implementing the various method embodiments described below. The data storage area may also store data created by the terminal during use (such as phonebook data, audio and video data, chat log data, etc.).

[0075] like Figure 7The diagram shows a structural block diagram of a computer-readable storage medium 400 provided in an embodiment of the present invention. The computer-readable medium stores program code 410, which can be called by a processor to execute the methods described in the above method embodiments.

[0076] The computer-readable storage medium 400 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 400 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 400 has storage space for program code 410 that performs any of the method steps described above. This program code 410 can be read from or written to one or more computer program products. The program code 410 may be compressed, for example, in a suitable form.

[0077] In summary, this invention provides a single-channel ABS vehicle speed calculation method and device. It calculates vehicle speed by acquiring only one wheel speed sensor signal, reducing sensor costs and achieving cost reduction. The single-wheel speed algorithm reduces fault alarms caused by abnormal square wave signals from two or one wheel. This further reduces the number of electronic components in the hardware, shrinks the overall ECU layout, and achieves product miniaturization. It also reduces hydraulic control circuits, allowing for the use of smaller motors for small-displacement vehicles, reducing the size of the hydraulic control unit and achieving product lightweighting. The single-channel ABS controls the front wheel hydraulic system, maximizing the braking performance of the disc brakes. During braking, the deceleration generated by the front brake is twice that of the rear brake. This solution allows even low-priced two-wheeled vehicles to be equipped with ABS, greatly improving the safety of two-wheeled vehicles during emergency braking.

[0078] In the embodiments disclosed in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0079] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0080] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for calculating ABS vehicle speed, characterized in that, The method includes: A wheel speed square wave signal is obtained by a wheel speed sensor installed on the front wheel of the motorcycle, and the corresponding wheel speed is calculated based on the wheel speed square wave signal. The wheel speed is delayed and corrected by comparing the wheel speed variable in the current detection cycle with that in the previous detection cycle. The vehicle speed is determined to increase or decrease based on the corrected wheel speed. If the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope, it is determined to be a decrease in vehicle speed. If the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope, it is determined to be an increase in vehicle speed. The calculation of the vehicle speed increase or decrease variable value is as follows: When the vehicle is not under ABS control, the increase variable value is a fixed value; when the vehicle is in the early stage of ABS control, the decrease variable value is calculated as follows: Determine if the vehicle deceleration is less than a preset second threshold; if so, the vehicle speed decrease variable value is twice the vehicle deceleration; if not, determine the front wheel deceleration and determine the decrease variable value based on the front wheel deceleration value. When the vehicle is under ABS control, the calculation method for the decrease variable value is as follows: When entering the first detection cycle of ABS control, it is determined whether the front wheel deceleration is less than the preset third threshold. If it is, the change in vehicle speed is 0.5 times the vehicle deceleration value. If not, the change in vehicle speed is the vehicle deceleration value. When entering the eighth detection cycle of ABS control, it is determined whether the maximum slip ratio of the vehicle is greater than the preset fourth threshold. If it is, the change in vehicle speed is the preset fixed change. If not, the change in vehicle speed is 0.8 times the vehicle deceleration value. The adjustment variable calculated from the wheel speed is compared with the vehicle deceleration value to obtain the correction parameter, and the vehicle deceleration value is corrected to calculate the vehicle speed.

2. The ABS vehicle speed calculation method according to claim 1, characterized in that, The step of delaying the wheel speed specifically includes: Determine whether the deviation between the wheel speed variable in the current detection cycle and the wheel speed variable in the previous detection cycle is less than a preset first threshold. If so, the wheel speed variable in the previous detection cycle remains at its current value. If not, determine whether the wheel speed variable of the current detection cycle is less than the wheel speed variable of the previous detection cycle. If yes, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope. If no, the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope.

3. The ABS vehicle speed calculation method according to claim 2, characterized in that, The step of calculating the increasing or decreasing value of the vehicle speed variable further includes: Obtain the peak wheel speed; Calculate the slope between the two peak wheel speed points; The calculated slope is used as the change in vehicle speed after the next wheel speed peak point.

4. The ABS vehicle speed calculation method according to claim 3, characterized in that, The step of calculating the increasing or decreasing value of the vehicle speed variable also includes: Determine if the calculated slope value is usable. If not, the change in vehicle speed is the vehicle deceleration value. If so, the calculated slope is corrected, and the corrected slope is used as the change in vehicle speed after the next wheel speed peak point.

5. The ABS vehicle speed calculation method according to claim 4, characterized in that, The step of correcting the calculated slope specifically includes: The slope between two wheel speed peaks is corrected based on wheel speed and road surface characteristics; Determine whether the road surface characteristics meet the characteristics of a high-adhesion road condition. If so, limit the slope value to a preset fifth threshold range. If not, use the slope as the change in vehicle speed.

6. The ABS vehicle speed calculation method according to claim 5, characterized in that, The steps for calculating vehicle speed specifically include: Multiply the decrease variable value by the length of the detection period to obtain the vehicle speed change in each period; Determine whether the vehicle speed variable is greater than the wheel speed variable in the current detection cycle. If so, the vehicle speed changes according to the calculated vehicle speed change amount, and cannot be less than the wheel speed. If not, further determine whether the vehicle speed variable is less than the wheel speed variable in the previous detection cycle. If so, the vehicle speed changes according to a preset positive fixed wheel speed change amount, and cannot be greater than the wheel speed variable in the previous detection cycle.

7. The ABS vehicle speed calculation method according to claim 6, characterized in that, The steps for calculating vehicle speed also specifically include: Vehicle speed deviation is detected. If a deviation in the vehicle speed curve is detected, the slope is reduced or increased by a certain coefficient.

8. An ABS vehicle speed calculation device, characterized in that, The device includes: The wheel speed detection unit is used to obtain a wheel speed square wave signal through a wheel speed sensor installed on the front wheel of the motorcycle, and to calculate the corresponding wheel speed based on the wheel speed square wave signal. The wheel speed correction unit is used to perform delay correction on the wheel speed by comparing the wheel speed variable of the current detection cycle with the wheel speed variable of the previous detection cycle. The rising and falling statistics unit is used to determine whether the vehicle speed is rising or falling based on the corrected wheel speed. If the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a negative slope, it is determined that the vehicle speed is falling. If the wheel speed variable of the previous detection cycle approaches the wheel speed variable of the current detection cycle with a positive slope, it is determined that the vehicle speed is rising. The change calculation unit is used to calculate the rising or falling variable value of vehicle speed. When the vehicle is not under ABS control, the rising variable value is a fixed value. When the vehicle is in the early stage of ABS control, the falling variable value is calculated as follows: Determine if the vehicle deceleration is less than a preset second threshold; if so, the vehicle speed decrease variable value is twice the vehicle deceleration; if not, determine the front wheel deceleration and determine the decrease variable value based on the front wheel deceleration value. When the vehicle is under ABS control, the calculation method for the decrease variable value is as follows: When entering the first detection cycle of ABS control, it is determined whether the front wheel deceleration is less than the preset third threshold. If it is, the change in vehicle speed is 0.5 times the vehicle deceleration value. If not, the change in vehicle speed is the vehicle deceleration value. When entering the eighth detection cycle of ABS control, it is determined whether the maximum slip ratio of the vehicle is greater than the preset fourth threshold. If it is, the change in vehicle speed is the preset fixed change. If not, the change in vehicle speed is 0.8 times the vehicle deceleration value. The vehicle speed calculation unit is used to compare the adjustment variable calculated from the wheel speed with the vehicle deceleration value to obtain the correction parameter, correct the vehicle deceleration value, and calculate the vehicle speed.

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