CN115743065A

CN115743065A - Single-channel ABS vehicle speed calculation method and device

Info

Publication number: CN115743065A
Application number: CN202211472657.9A
Authority: CN
Inventors: 单东升; 陈赞; 王琛
Original assignee: Ningbo Saifu Automobile Brake Co ltd
Current assignee: Ningbo Saifu Automobile Brake Co ltd
Priority date: 2022-11-17
Filing date: 2022-11-17
Publication date: 2023-03-07

Abstract

The invention provides a method and a device for calculating the vehicle speed of a single-channel ABS (anti-lock brake system), which can calculate the vehicle speed by only acquiring a wheel speed sensor signal, reduce the sensor cost and realize cost reduction of products. The vehicle speed algorithm development based on the single wheel speed reduces the fault alarm caused by the abnormal speed signals of two wheels or one wheel. And then reduce the electronic components of hardware, reduce whole ECU's overall arrangement, realize the miniaturization of product and reduce hydraulic control circuit, to small discharge capacity motorcycle type development, can select the small-size motor, reduce the volume of hydraulic control unit, realize the lightweight of product. The single-channel ABS is used for controlling a hydraulic system of the front wheel, the maximum braking performance of the disc brake is exerted, and in the braking process, the deceleration generated by the front brake is 2 times that of the rear brake. This scheme allows can let 2 wheelers of low price can both install ABS, very big improvement the security of 2 wheelers under the emergency braking condition.

Description

Single-channel ABS vehicle speed calculation method and device

Technical Field

The invention relates to the technical field of computers, in particular to a method and a device for calculating the speed of a single-channel ABS vehicle.

Background

With market warming and technological progress in the motorcycle industry, anti-lock brake system (ABS) is more and more commonly equipped on two-wheeled motorcycles, from the first one only on large displacement (above 250 cc), to the current one on small displacement (150 cc and below), and is expected to become the standard safety configuration of 2-wheeled motorcycles.

In the market at present, the ABS product of the motorcycle mainly comprises a double-wheel speed sensor and a double-channel hydraulic control unit, so that the ABS product is difficult to popularize low-end motorcycle types in cost and is generally assembled only on high-end or high-mix motorcycle types. In the existing scheme, the ABS needs to have 2 wheel speed sensors to acquire wheel speed signals of front wheels and rear wheels, and estimate the vehicle speed of the vehicle in the braking process according to a vehicle speed algorithm, so as to acquire the slip rate of the front wheels or the rear wheels, so as to control a Hydraulic Control Unit (HCU), stabilize the braking force in a reasonable pressure range, and finally ensure the stable braking of the vehicle until the vehicle stops. The dual channel ABS needs to control the hydraulic pressure of the front and rear wheels, thus requiring two wheel speed sensors and two valve control loops.

The scheme has the defects that the vehicle speed algorithm of the double-channel ABS is calculated based on the front and rear wheel speed signals, the stability and the accuracy of the vehicle speed signal are greatly influenced by the front and rear wheel speeds, when one wheel speed sensor of a vehicle is abnormal, for example, the signal is lost due to the damage of a connector, the signal is protruded due to the damage of a wheel speed gear ring, the wheel speed is failed due to the wheel speed deviation lamp caused by the size change of a wheel, the double-channel ABS function can report the fault, and the whole ABS function is failed.

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

Disclosure of Invention

In order to solve the problems, the invention provides a method and a device for calculating the vehicle speed of a single-channel ABS.

In a first aspect of the embodiments of the present invention, a method for calculating a vehicle speed of a single-channel ABS is provided, where the method includes:

obtaining a wheel speed square wave signal through a wheel speed sensor arranged on a front wheel of the motorcycle, and calculating to obtain a corresponding wheel speed according to the wheel speed square wave signal;

carrying out delay correction on the wheel speed;

determining the rise or fall of the vehicle speed according to the corrected wheel speed;

calculating an ascending variable value or a descending variable value of the vehicle speed;

the vehicle deceleration value is corrected to calculate the vehicle speed.

Optionally, the step of performing a delay correction on the wheel speed specifically includes:

judging whether the deviation value of the wheel speed variable of the current detection period and the wheel speed variable of the previous detection period is smaller than a preset first threshold value or not, and if so, keeping the wheel speed variable of the previous detection period at the current value;

if not, judging whether the wheel speed variable of the current detection period is smaller than the wheel speed variable of the previous detection period, if so, approaching the wheel speed variable of the current detection period by the wheel speed variable of the previous detection period with a negative slope, and if not, approaching the wheel speed variable of the current detection period by the wheel speed variable of the previous detection period with a positive slope.

Optionally, when the vehicle is in a non-ABS control state, the value of the rising variable is a fixed value, and when the vehicle is in an early stage of ABS control, the value of the falling variable is calculated by:

judging whether the deceleration of the vehicle is smaller than a preset second threshold value or not;

if so, the value of the drop variable of the vehicle speed is twice of the deceleration of the vehicle,

if not, the front wheel deceleration is judged, and an appropriate value is set for the descent variable value according to the value of the front wheel deceleration.

Optionally, when the vehicle is in the ABS control state, the step of calculating an increasing variable value or a decreasing variable value of the vehicle speed specifically includes:

when the vehicle enters a first detection period of ABS control, judging whether the deceleration of front wheels is smaller than a preset third threshold, if so, determining that the vehicle speed reduction variation is 0.5 times of the vehicle deceleration value, and if not, determining that the vehicle speed reduction variation is the vehicle deceleration value;

and when the vehicle enters an eighth detection period of the ABS control, judging whether the maximum slip ratio of the vehicle is greater than a preset fourth threshold, if so, determining that the vehicle speed reduction variation is a preset fixed variation, and if not, determining that the vehicle speed reduction variation is 0.8 times of the vehicle deceleration value.

Optionally, the step of calculating an ascending variable value or a descending variable value of the vehicle speed further includes:

acquiring a wheel speed peak value;

calculating the slope between the front and rear wheel speed peak points;

the calculated slope is used as the vehicle speed decrease change amount after the subsequent wheel speed peak point.

judging whether the calculated slope value is available, if not, the vehicle speed reduction variation is a vehicle deceleration value,

if yes, the calculated slope is corrected, and the corrected slope is used as the vehicle speed reduction change amount after the next wheel speed peak point.

Optionally, the step of correcting the calculated slope specifically includes:

correcting the slope between two wheel speed peak values according to the wheel speed and the road surface characteristics;

and judging whether the road surface characteristics accord with the characteristics of the high-adhesion road condition, if so, limiting the slope value in a preset fifth threshold interval, and if not, taking the slope as the vehicle speed reduction variation.

Optionally, the step of calculating the vehicle speed specifically includes:

multiplying the descending variable value by the time length of the detection period to obtain the vehicle speed variation of each period;

judging whether the vehicle speed variable is greater than the wheel speed variable of the current detection period, if so, changing the vehicle speed according to the calculated vehicle speed variable quantity, and enabling the vehicle speed variable quantity not to be less than the wheel speed; if not, further judging whether the vehicle speed variable is smaller than the wheel speed variable of the last detection period, if so, changing the vehicle speed by a preset positive fixed wheel speed variable quantity, and not being larger than the wheel speed variable of the last detection period.

Optionally, the step of calculating a vehicle speed further specifically includes:

and identifying the vehicle speed deviation, and if the vehicle speed curve deviation is judged to occur, reducing or amplifying the slope by a certain coefficient.

In a second aspect of the embodiments of the present invention, there is provided an ABS vehicle speed calculation device, the device including:

the wheel speed detection unit is used for obtaining a wheel speed square wave signal through a wheel speed sensor arranged on the front wheel of the motorcycle and calculating a corresponding wheel speed according to the wheel speed square wave signal;

a wheel speed correction unit for performing delay correction on a wheel speed;

the rising and falling statistical unit is used for determining rising or falling of the vehicle speed according to the corrected wheel speed;

a variation calculating unit for calculating an up-variable value or a down-variable value of the vehicle speed;

and a vehicle speed calculation unit for correcting the vehicle deceleration value and calculating the vehicle speed.

In a third aspect of the embodiments of the present invention, there is provided an electronic device, including:

one or more processors; a 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, the one or more programs configured to perform the method of the first aspect.

In a fourth aspect of the embodiments of the present invention, a computer-readable storage medium is provided, where a program code is stored in the computer-readable storage medium, and the program code is called by a processor to execute the method according to the first aspect.

In summary, the invention provides a method and a device for calculating the vehicle speed of a single-channel ABS vehicle, which can calculate the vehicle speed by only acquiring a wheel speed sensor signal, thereby reducing the sensor cost and realizing cost reduction of the product. The vehicle speed algorithm development based on the single wheel speed reduces the fault alarm caused by the abnormal wheel speed signals of two wheels or one wheel. And then reduce the electronic components of hardware, reduce whole ECU's overall arrangement, realize the miniaturization of product and reduce hydraulic control circuit, to small discharge capacity motorcycle type development, can select the small-size motor, reduce the volume of hydraulic control unit, realize the lightweight of product. The single-channel ABS is used for controlling a hydraulic system of the front wheel, the maximum braking performance of the disc brake is exerted, and in the braking process, the deceleration generated by the front brake is 2 times that of the rear brake. This scheme allows can let 2 wheelers of low price can both install ABS, very big improvement the security of 2 wheelers under the emergency braking condition.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a flow chart of a method for calculating vehicle speed of a single-channel ABS according to an embodiment of the invention;

FIG. 2 is a schematic diagram illustrating wheel speed peak selection according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a case where a slope correction is required according to an embodiment of the present invention;

FIG. 4 is a schematic illustration of the effect of the vehicle speed deviation after identification correction according to the embodiment of the present invention;

FIG. 5 is a functional block diagram of an ABS vehicle speed calculation device according to an embodiment of the invention;

fig. 6 is a block diagram of an electronic device for executing a single-channel ABS vehicle speed calculation method according to an embodiment of the present application.

Fig. 7 is a block diagram of a computer-readable storage medium storing or carrying program code for implementing a method for calculating a vehicle speed in a single-channel ABS according to an embodiment of the present application.

Icon:

a wheel speed detection unit 110; a wheel speed correction unit 120; a rising-falling statistic unit 130; a variation amount calculation unit 140; a vehicle speed calculation unit 150; an electronic device 300; a processor 310; a memory 320; a computer-readable storage medium 400; program code 410.

Detailed Description

With market warming and technological progress in the motorcycle industry, the arrangement of an anti-lock brake system (ABS) on a two-wheeled motorcycle is more and more common, and from the initial arrangement only on a large displacement (more than 250 cc) to the detection of a small displacement (150 cc and below) motorcycle type, the ABS is expected to become the standard safety configuration of the 2-wheeled motorcycle.

In the market at present, the ABS products of the motorcycles mainly comprise double-wheel speed sensors and double-channel hydraulic control units, so that the ABS products are difficult to popularize in low-end motorcycle types in cost and are generally assembled only in high-end or high-mix motorcycle types. In the existing scheme, the ABS needs to have 2 wheel speed sensors to acquire wheel speed signals of front wheels and rear wheels, and estimate the vehicle speed of the vehicle in the braking process according to a vehicle speed algorithm, so as to acquire the slip rate of the front wheels or the rear wheels, so as to control a Hydraulic Control Unit (HCU), stabilize the braking force in a reasonable pressure range, and finally ensure the stable braking of the vehicle until the vehicle stops. The dual channel ABS needs to control the hydraulic pressure of the front and rear wheels, thus requiring two wheel speed sensors and two valve control loops.

The technical scheme has the disadvantages that the speed algorithm of the double-channel ABS is obtained by calculation based on the front wheel speed signal and the rear wheel speed signal, the stability and the accuracy of the speed signal are greatly influenced by the front wheel speed and the rear wheel speed, when one wheel speed sensor of the vehicle is abnormal, for example, signals are lost due to the damage of a connector, signal protruding strips are caused due to the damage of a wheel speed gear ring, the wheel speed is failed due to the fact that a wheel speed deviation lamp caused by the change of the size of the wheel, the double-channel ABS function reports faults, and therefore the whole ABS function fails.

In view of this, the designer of the invention designs a single-channel ABS vehicle speed calculation method and device, which can calculate the vehicle speed by obtaining a wheel speed sensor signal, reduce the sensor cost, and realize cost reduction of the product. The vehicle speed algorithm development based on the single wheel speed reduces the fault alarm caused by the abnormal wheel speed signals of two wheels or one wheel. And then reduce the electronic components of hardware, reduce whole ECU's overall arrangement, realize the miniaturization of product and reduce hydraulic control circuit, to small discharge capacity motorcycle type development, can select the small-size motor, reduce the volume of hydraulic control unit, realize the lightweight of product. The single-channel ABS is used for controlling a hydraulic system of the front wheel, the maximum braking performance of the disc brake is exerted, and in the braking process, the deceleration generated by the front brake is 2 times that of the rear brake. This scheme allows can let 2 wheelers of low price can both install ABS, very big improvement the security of 2 wheelers under the emergency braking condition.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "top", "bottom", "inside", "outside", and the like refer to orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships conventionally used to place products of the present invention, and are used for convenience in describing the present invention and simplifying the description, but do not refer to or imply that the devices or elements referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in a specific case to those of ordinary skill in the art.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

Examples

The single-channel ABS vehicle speed calculation method and device provided by the embodiment are applied to a motorcycle provided with an ABS anti-lock brake control system. The main working principle of the ABS anti-lock brake control system is as follows: the front and rear wheel speed sensors detect wheel speed square wave signals and input the signals into the electronic control unit, the electronic control unit calculates the slip rate of the vehicle, when the wheels are found to have locking tendency, the brake force is overlarge at the moment, the control unit outputs control signals to the electromagnetic valve, the wheel cylinder pressure is reduced through the opening and closing of the valve, when the pressure is too low, the wheel speed is accelerated, the slip rate calculated by the controller is reduced, and the wheel cylinder pressure is adjusted through controlling the electromagnetic valve. The ABS controller adjusts the braking pressure of the wheel cylinder through the hydraulic control unit, prevents wheels from locking, enables the wheels to be kept near the optimal slip rate all the time, and keeps the optimal braking state. The motorcycle ABS has the following functions: the lateral stability of the vehicle during braking is improved, the directional operability of the vehicle during braking is improved, and the braking efficiency is improved.

ABS brake control belongs to closed-loop control, and the input quantity of the motorcycle brake process is that a driver holds a hand brake tightly to drive the interior of a main cylinder to generate hydraulic pressure, and the hydraulic pressure acts on calipers through a hydraulic module of the ABS. The whole ABS system has one and only one input signal, which is input by a wheel speed sensor. A wheel speed sensor is mounted on the front wheel and obtains an analog signal corresponding to a change in the wheel speed. The wheel is used as a controlled object and is decelerated under the action of the caliper in the braking process, the caliper is driven by hydraulic action, the hand brake force directly acts on the caliper in a non-ABS control state, and the hand brake force can be processed by the ABS in an ABS state to output force for effectively preventing the wheel from being locked. Whether the ABS is started or not depends on the slip ratio calculated by the wheel speed and the vehicle speed, when the slip ratio is larger than the ABS threshold value, the wheels tend to be locked, the vehicle tends to be unstable, and the ABS is started to control the braking force. The direct object of control is a valve in an ABS Hydraulic Control Unit (HCU), and the opening and closing of the valve can effectively control the hydraulic pressure acting on the caliper, so that the effect of controlling the wheel speed is achieved.

The execution logic of the ABS algorithm control is that the signals obtained by the wheel speed sensor are analog square wave signals, and the speed of the vehicle corresponds to the change frequency of the square wave. The ABS algorithm first needs to convert the analog signal into a wheel speed signal that can reflect the braking of the vehicle, and the simple wheel speed signal may have jitter caused by signal interference, so that the wheel speed needs to be filtered to obtain a smoother wheel speed signal. The signal is obtained by calculating according to wheel speed through an algorithm without a sensor, the current slip rate can be calculated by the aid of the vehicle speed and the wheel speed, the stable state of the current vehicle can be judged through the slip rate signal, and the road surface state where the vehicle is possibly located is identified according to the current wheel speed signal, so that whether the ABS is required to be started for anti-lock braking control or not is judged. The ABS controller is from vehicle controller to axle controller to wheel controller, calculates the accurate control time to achieve the anti-lock control effect, and finally converts the control time into the switch command of corresponding valve, drives the valve motor, etc. to perform the hydraulic control of brake fluid, and makes the brake force keep in the effective control range, thereby making the slip ratio of wheel and ground controlled in the optimum interval.

On the basis, as shown in fig. 1, for the single-channel ABS vehicle speed calculation method provided in an embodiment of the present invention, the basic logic of the vehicle speed algorithm is that only one wheel speed curve is used as a reference under the single-channel ABS control module, the change of the vehicle speed needs to be adjusted in real time according to the change of the wheel speed, the adjustment variable calculated from the wheel speed is compared with the deceleration value to obtain a more appropriate correction parameter, and finally the vehicle speed is calculated.

Specifically, the method comprises the following steps:

step S101, a wheel speed square wave signal is obtained through a wheel speed sensor arranged on a front wheel of the motorcycle, and a corresponding wheel speed is obtained through calculation according to the wheel speed square wave signal.

Step S102, delay correction is carried out on the wheel speed;

since the wheel speed fluctuates up and down after the speed rises and the actual vehicle speed has a certain delay for the wheel speed, the wheel speed is corrected in a delayed manner, and the corrected wheel speed is regarded as the current vehicle speed.

As a preferred embodiment of the present invention, the step of correcting the wheel speed delay specifically includes:

if not, judging whether the wheel speed variable of the current detection period is smaller than the wheel speed variable of the previous detection period, if so, approaching the wheel speed variable of the previous detection period to the wheel speed variable of the current detection period by a negative slope, and if not, approaching the wheel speed variable of the previous detection period to the wheel speed variable of the current detection period by a positive slope.

Preferably, the first threshold value is 0.06.

The purpose of wheel speed correction is to filter out micro-jitter in wheel speed data and process the filtered wheel speed so that the control is not disturbed. The descending correction amount and the ascending correction amount are fixed amounts under non-ASB control, so that the curve change of the corrected wheel speed in each period is relatively regular. The term of less than 0.06 is used to maintain a certain deviation between the vehicle speed and the wheel speed, and for the actual vehicle speed and the wheel speed, the wheel speed is greater than the vehicle speed in the case of acceleration and less than the vehicle speed in the case of deceleration.

Step S103, determining the rise or fall of the vehicle speed according to the corrected wheel speed;

and the wheel speed variable of the previous detection period approaches the wheel speed variable of the current detection period by a negative slope and is determined as the speed reduction, and the wheel speed variable of the previous detection period approaches the wheel speed variable of the current detection period by a positive slope and is determined as the speed reduction.

Step S104, calculating an ascending variable value or a descending variable value of the vehicle speed;

in the embodiment of the invention, an appropriate calculation mode is selected according to whether the ABS control state is present.

In a preferred embodiment of the present invention, the value of the rising variable is a fixed value when the vehicle is in a non-ABS control state, and the value of the falling variable is calculated in such a manner that:

if so, the value of the drop variable of the vehicle speed is twice the deceleration of the vehicle,

The early stage of the ABS control specifically refers to a time period when braking is started, but the slip rate does not reach an ABS intervention threshold.

Preferably, the second threshold value is-2.5 m/s 2.

Different variation values are obtained when the deceleration is-2.5 m/s 2, the deceleration reflects the current running state of the vehicle, the filtered wheel deceleration reflects the wheel changing state, the running state of the vehicle cannot be greatly influenced by the change of the wheels, so a specific value needs to be set for the vehicle speed variation under different wheel decelerations, and the minimum value of the total variation does not exceed-10. It should be noted that: after the variation is calculated, the variation is multiplied by the detection period time, and the variation of the vehicle speed in each period is obtained. When the wheel speed is higher than the vehicle speed, the vehicle speed approaches to the wheel speed by a fixed ascending variable, when the vehicle is braked, the wheel speed is reduced, the wheel speed is lower than the vehicle speed, at the moment, a proper descending slope variable is given to the vehicle speed according to the current vehicle deceleration and the wheel deceleration (namely, the vehicle speed descending variable quantity is taken as the descending slope to approach to the wheel speed in each calculation period), so that the estimated value of the vehicle speed can approach to the actual vehicle speed as much as possible, and the effective braking of the ABS is ensured.

As a preferred embodiment implemented by the invention, the variable calculation under the ABS control state mainly comprises three parts:

a first part: and selecting the vehicle speed variation just entering the ABS.

At this time, when the vehicle is in the ABS control state, the step of calculating the value of the rising variable or the value of the falling variable of the vehicle speed specifically includes:

when the vehicle enters a first detection period of ABS control, judging whether the deceleration of front wheels is smaller than a preset third threshold, if so, determining that the vehicle speed reduction variation is 0.5 times of the vehicle deceleration value, and if not, determining that the vehicle speed reduction variation is the vehicle deceleration value; preferably, the third threshold value is-60.

And when the vehicle enters an eighth detection period of the ABS control, judging whether the maximum slip ratio of the vehicle is greater than a preset fourth threshold, if so, determining that the vehicle speed reduction variation is a preset fixed variation, and if not, determining that the vehicle speed reduction variation is 0.8 times of the vehicle deceleration value. Preferably, the fourth threshold value is 0.13.

When the ABS control is just started, signals which can be used for making reference for subsequent vehicle speed change are few, the deceleration at the moment is in a state before the ABS is started, and the only signal which can be used as the reference and can estimate the vehicle speed change situation after the deceleration is a wheel deceleration signal. Because the acting force generated by the forced action on the wheels can cause the wheel speed change to be different under different road adhesion coefficients, the higher the adhesion road surface is, the larger the reacting force on the brake is, the larger the wheel speed change can be, but the acting time is shorter, the wheel deceleration can be always kept at a lower deceleration value. Under a low-adhesion road surface, the wheel does not immediately recover the wheel speed even in a depressurized state because the friction of the ground is small, and therefore, the wheel deceleration value is in a large range and continues for a long period of time under the low-adhesion road surface.

The processing flow of the ABS is divided into two stages, wherein the first stage is just entering the ABS, the vehicle speed variation is changed by deceleration vehicle deceleration value, the second stage is the 8 th detection period after entering, the deceleration value and the slip rate of the wheel at the time are judged, the deceleration value of the wheel under the high-adhesion road surface rises, the slip rate is generally small, the deceleration value of the wheel under the low-adhesion road surface is large, and the change process of the wheel speed lasts for a period of time. Of course, the condition of the medium-attachment road surface may enter the condition of the high-attachment judgment, so that the correction amount is limited to-6 in the flow of this section, and the correction amount is not too much. However, the high-adhesion road surface may be erroneously determined as the low-adhesion process, but this does not affect the subsequent vehicle speed change.

A second part: and acquiring a wheel speed peak value according to the wheel speed shaking condition, and calculating the slope of the front wheel speed peak value point and the back wheel speed peak value point as the variation of the vehicle speed change. The method comprises the following specific steps:

acquiring a wheel speed peak value;

calculating the slope between the front and rear wheel speed peak points;

The wheel speed peak is selected as shown in fig. 2. The smoother curve in the graph is the corrected wheel speed curve, and the ascending and descending variables are fixed, so that the judgment of the ascending and descending conditions is facilitated. The reference numeral 1 is a first wheel speed peak point, the reference numeral 2 is a second wheel speed peak point, the wheel speed peak values of the two points are taken to calculate the slope between the two points, and the calculated slope is taken as the variation of the vehicle speed after the reference numeral 2.

Wherein, the step of correcting the calculated slope further comprises:

correcting the slope between the two wheel speed peak values according to the wheel speed and the road surface characteristics;

and judging whether the road surface characteristics accord with the characteristics of the high-adhesion road condition, if so, limiting the slope value in a preset fifth threshold interval, and if not, taking the slope as the vehicle speed reduction variation. Preferably, the fifth threshold interval takes on a value (-9, -7).

And a third part: when the peak slope is not suitable or special road conditions and driving conditions occur, deceleration is adopted, the last calculated peak slope and the coefficient multiple of the deceleration are compared, and the minimum reference value is selected as the variable of the vehicle speed change.

In a preferred embodiment, after calculating the slope between the front and rear wheel speed peak points, it is further determined whether the calculated slope value is usable, if not, the vehicle speed reduction variation is the vehicle deceleration value, and if so, the calculated slope is corrected, and the corrected slope is used as the vehicle speed reduction variation after the rear wheel speed peak point.

Specifically, as shown in fig. 3, the slope is calculated from two points 1 and 2, and the slope calculated from two points 2 and 3 is large, and the peaks of the two points are almost at the same position when calculating the slope, so the obtained slope is small, and the difference between the calculated slopes of the two points 1 and 2 is large. This case is corrected by deceleration, and the vehicle speed after reference numeral 3 is changed to the minimum value between the slope calculated last time and the deceleration as a variable.

In step S105, the vehicle deceleration value is corrected to calculate the vehicle speed.

As a preferred embodiment of the present invention, the step of calculating the vehicle speed specifically includes:

judging whether the vehicle speed variable is larger than the wheel speed variable of the current detection period, if so, changing the vehicle speed according to the calculated vehicle speed variable quantity, and not being smaller than the wheel speed; and if so, further judging whether the vehicle speed variable is smaller than the wheel speed variable of the last detection period, and if so, changing the vehicle speed by a preset positive fixed wheel speed variable quantity which cannot be larger than the wheel speed variable of the last detection period.

When the vehicle speed is larger than the wheel speed variable of the current detection period of the upper reference wheel speed curve, the vehicle speed is reduced according to the real-time calculated variable quantity, and when the vehicle speed is smaller than the wheel speed variable of the last detection period of the lower reference wheel speed curve, the vehicle speed is increased according to the fixed rising variable. Preferably, the positive fixed wheel speed varies by +0.035 m/s/cycle. Typically each period is 5ms in length.

In order to adjust the vehicle speed in time when a deviation occurs, the deviation is identified in the vehicle speed calculation. And if the deviation of the vehicle speed curve is judged to occur, reducing or amplifying the slope by a certain coefficient.

The specific judgment mode comprises two aspects which are respectively as follows:

1. and judging whether the current wheel speed is greater than the wheel speed by more than 0.1 deviation of the peak wheel speed, if so, further judging whether the vehicle deceleration is greater than-4 and whether the minimum value identified by the wheel deceleration in the descending and ascending processes of the wheel speed is less than-10, and if so, reducing the slope by a factor of 0.8.

2. And judging whether the current vehicle speed is greater than the deviation of the wheel speed peak point by more than 0.2, if so, further judging whether the vehicle deceleration is greater than-4, and if so, amplifying the slope by a factor of 1.2 times.

The effect of the vehicle speed deviation after the identification correction is as shown in fig. 4, in which the curve in the broken line frame is deviated downward, and in order to make the vehicle speed after the identification more realistic, the following calculation variables are processed by adding coefficients.

It should be noted that the above correction flow is only for the medium-low additional road condition, and only for the change situation with deceleration as the vehicle speed correction amount, because this situation illustrates that the deceleration estimation value at this time is already large, and the adjustment processing is required.

In conclusion, the single-channel ABS vehicle speed calculation method provided by the embodiment can calculate the vehicle speed by only acquiring one path of wheel speed sensor signal, so that the sensor cost is reduced, and the cost of the product is reduced. The vehicle speed algorithm development based on the single wheel speed reduces the fault alarm caused by the abnormal speed signals of two wheels or one wheel. And then reduce the electronic components of hardware, reduce whole ECU's overall arrangement, realize the miniaturization of product and reduce hydraulic control circuit, to small discharge capacity motorcycle type development, can select the small-size motor, reduce the volume of hydraulic control unit, realize the lightweight of product. The single-channel ABS is used for controlling a hydraulic system of the front wheel, the maximum braking performance of the disc brake is exerted, and in the braking process, the deceleration generated by the front brake is 2 times that of the rear brake. This scheme allows can let 2 wheelers of low price can both install ABS, very big improvement the security of 2 wheelers under the emergency braking condition.

As shown in fig. 5, the ABS vehicle speed calculation apparatus according to the embodiment of the present invention includes:

a wheel speed detection unit 110, configured to obtain a wheel speed square wave signal through a wheel speed sensor mounted on a front wheel of a motorcycle, and calculate a corresponding wheel speed according to the wheel speed square wave signal;

a wheel speed correction unit 120 for performing delay correction on the wheel speed;

a rise-and-fall statistical unit 130 for determining a rise or fall of a vehicle speed according to the corrected wheel speed;

a variation calculating unit 140 for calculating an up-variable value or a down-variable value of the vehicle speed;

vehicle speed calculating means 150 corrects the vehicle deceleration value and calculates the vehicle speed.

The ABS vehicle speed calculation apparatus provided in the embodiment of the present invention is used to implement the above single-channel ABS vehicle speed calculation method, and therefore the specific implementation is the same as the above method, and is not described herein again.

As shown in fig. 6, a block diagram of an electronic device 300 according to an embodiment of the present invention is provided. The electronic device 300 may be a smart phone, a tablet computer, an electronic book, or the like, which is capable of running an application program. The electronic device 300 in the present 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 may be stored in the memory 320 and configured to be executed by the one or more processors 310, the one or more programs configured to perform a method as described in the aforementioned method embodiments.

Processor 310 may include one or more processing cores. The processor 310 connects various parts throughout the electronic device 300 using various interfaces and lines, and performs various functions of the electronic device 300 and processes data by executing or executing instructions, programs, code sets, or instruction sets stored in the memory 320 and calling data stored in the memory 320. Alternatively, the processor 310 may be implemented in at least one hardware form of Digital Signal Processing (DSP), field-Programmable Gate Array (FPGA), and Programmable Logic Array (PLA). The processor 310 may integrate one or more of a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a modem, and the like. Wherein, the CPU mainly processes an operating system, a user interface, an application program and the like; the GPU is used for rendering and drawing display content; the modem is used to handle wireless communications. It is understood that the modem may not be integrated into the processor 310, but may be implemented by a communication chip.

The Memory 320 may include a Random Access Memory (RAM) or a Read-Only Memory (Read-Only Memory). The memory 320 may be used to store instructions, programs, code sets, or instruction sets. The memory 320 may include a stored program area and a stored data area, wherein the stored program area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a touch function, a sound playing function, an image playing function, etc.), instructions for implementing various method embodiments described below, and the like. The storage data area may also store data created by the terminal in use, such as a phonebook, audio-video data, chat log data, and the like.

As shown in fig. 7, an embodiment of the invention provides a block diagram of a computer-readable storage medium 400. The computer readable medium has stored therein a program code 410, said program code 410 being invokable by the processor for performing the method described in the above method embodiments.

The computer-readable storage medium 400 may be an electronic memory such as a flash memory, an EEPROM (electrically erasable programmable read only memory), an EPROM, a hard disk, or a ROM. Alternatively, the computer-readable storage medium 400 includes a non-volatile computer-readable storage medium. The computer readable storage medium 400 has storage space for program code 410 for performing any of the method steps of the method described above. The program code 410 can be read from or written to one or more computer program products. Program code 410 may be compressed, for example, in a suitable form.

In the embodiments disclosed in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The apparatus embodiments described above are merely illustrative and, for example, the flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

In addition, functional modules in the embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

The functions, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer-readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk, and various media capable of storing program codes.

Claims

1. A single-channel ABS vehicle speed calculation method is characterized by comprising the following steps:

obtaining a wheel speed square wave signal through a wheel speed sensor arranged on a front wheel of the motorcycle, and calculating according to the wheel speed square wave signal to obtain a corresponding wheel speed;

carrying out delay correction on the wheel speed;

the vehicle deceleration value is corrected to calculate the vehicle speed.

2. The single-channel ABS vehicle speed calculation method according to claim 1, wherein the step of performing the delay correction on the wheel speed specifically comprises:

3. The single-channel ABS vehicle speed calculation method of claim 2, wherein when the vehicle is in a non-ABS control state, the value of the rising variable is a fixed value, and when the vehicle is in an early stage of ABS control, the value of the falling variable is calculated by:

if not, the deceleration of the front wheel is judged, and an appropriate value is set for the value of the drop variable according to the value of the deceleration of the front wheel.

4. The single-channel ABS vehicle speed calculation method of claim 3, wherein when the vehicle is in the ABS control state, the step of calculating the value of the rising variable or the value of the falling variable of the vehicle speed specifically comprises:

5. The single-channel ABS vehicle speed calculation method according to claim 4, wherein the step of calculating the value of the rising variable or the value of the falling variable of the vehicle speed further comprises:

acquiring a wheel speed peak value;

calculating the slope between the front and rear wheel speed peak points;

6. The single-channel ABS vehicle speed calculation method of claim 5, wherein the step of calculating the value of the rising variable or the value of the falling variable of the vehicle speed further comprises:

judging whether the calculated slope value is usable or not, if not, the vehicle speed reduction variation is a vehicle deceleration value,

7. The single-channel ABS vehicle speed calculation method of claim 6 wherein the step of correcting the calculated slope includes:

8. The single-channel ABS vehicle speed calculation method according to claim 7, wherein the step of calculating the vehicle speed specifically comprises:

judging whether the vehicle speed variable is larger than the wheel speed variable of the current detection period, if so, changing the vehicle speed according to the calculated vehicle speed variable quantity, and not being smaller than the wheel speed; if not, further judging whether the vehicle speed variable is smaller than the wheel speed variable of the last detection period, if so, changing the vehicle speed by a preset positive fixed wheel speed variable quantity, and not being larger than the wheel speed variable of the last detection period.

9. The method for calculating the vehicle speed of the single-channel ABS according to claim 8, wherein the step of calculating the vehicle speed further comprises:

and carrying out vehicle speed deviation identification, and if judging that the vehicle speed curve deviates, reducing or amplifying the slope by a certain coefficient.

10. An ABS vehicle speed calculation apparatus, characterized in that the apparatus comprises:

a wheel speed correction unit for performing delay correction on a wheel speed;