Wheel speed correction method, device and electronic equipment

Abstract

The application discloses a wheel speed correction method and device and electronic equipment, wherein the method comprises the following steps: acquiring wheel speed of a vehicle at a current sampling moment when the vehicle is steering; correcting first left front wheel speed and first right front wheel speed by using the wheel speed to obtain second left front wheel speed and second right front wheel speed; determining corrected left front wheel speed at the current sampling moment according to a difference between the second left front wheel speed and left front wheel speed corrected at a previous sampling moment; and determining corrected right front wheel speed at the current sampling moment according to a difference between the second right front wheel speed and right front wheel speed corrected at the previous sampling moment. Through the above steps, the left front wheel speed and the right front wheel speed are corrected when the vehicle is steering, and the wheel speed without the influence of wheel steering angle speed can be output, so that the accuracy of the wheel speed output is improved.

Description

Technical Field

[0001] This application belongs to the field of vehicle technology, and in particular relates to a wheel speed correction method, device and electronic equipment. Background Technology

[0002] Wheel speed sensors measure the angular velocity of a car's wheels and are currently widely used in passenger vehicles. Current post-processing methods for wheel speed signals primarily involve filtering.

[0003] The purpose of using wheel speed signals in chassis domain dynamics control algorithms is mainly twofold: first, to estimate the vehicle's speed relative to the ground using easily measurable wheel speeds; and second, to obtain the actual wheel rotation speed to calculate wheel slippage. For the first purpose, the algorithm often assumes that the linear velocity obtained by multiplying the wheel speed by the wheel radius represents the vehicle's speed relative to the ground at that wheel's position. Therefore, the closer the wheel speed signal is to this assumption, the more accurate the vehicle speed estimated by the algorithm.

[0004] However, the current estimation method has a large error in obtaining the wheel speed when the wheel is turning, and the wheel speed output is not accurate enough. Summary of the Invention

[0005] This application provides a wheel speed correction method, apparatus, and electronic device that can correct wheel speed when the wheel is turning, thereby improving the accuracy of wheel speed output.

[0006] In a first aspect, embodiments of this application provide a wheel speed correction method, including:

[0007] While the vehicle is turning, the wheel speeds of the vehicle measured at the current sampling time are obtained, and the wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed.

[0008] Using the wheel speeds, the first left front wheel speed and the first right front wheel speed are corrected to obtain the second left front wheel speed and the second right front wheel speed;

[0009] Based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, the corrected left front wheel speed at the current sampling time is determined, wherein the corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed.

[0010] Based on the difference between the second right front wheel speed and the right front wheel speed corrected at the previous sampling time, the corrected right front wheel speed at the current sampling time is determined, wherein the corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed.

[0011] Secondly, embodiments of this application provide a wheel speed correction device, comprising:

[0012] The first acquisition module is used to acquire the wheel speeds of the vehicle measured at the current sampling time when the vehicle is turning. The wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed.

[0013] The second acquisition module is used to use the wheel speed to correct the first left front wheel speed and the first right front wheel speed to obtain the second left front wheel speed and the second right front wheel speed.

[0014] The first determining module is used to determine the corrected left front wheel speed at the current sampling time based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, wherein the corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed.

[0015] The second determining module is used to determine the corrected right front wheel speed at the current sampling time based on the difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time, wherein the corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed.

[0016] Thirdly, embodiments of this application provide an electronic device, the device including: a processor and a memory storing computer program instructions;

[0017] When the processor executes the computer program instructions, it implements the method as described in the first aspect.

[0018] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions that, when executed by a processor, implement the method described in the first aspect.

[0019] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the method described in the first aspect.

[0020] The wheel speed correction method, apparatus, and electronic device of this application include: when a vehicle is turning, acquiring the wheel speeds of the vehicle measured at the current sampling time, the wheel speeds including a first left front wheel speed, a first right front wheel speed, a first left rear wheel speed, and a first right rear wheel speed; using the wheel speeds, correcting the first left front wheel speed and the first right front wheel speed to obtain a second left front wheel speed and a second right front wheel speed; determining the corrected left front wheel speed at the current sampling time based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, the corrected left front wheel speed being either the first left front wheel speed or the second left front wheel speed; and determining the corrected right front wheel speed at the current sampling time based on the difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time, the corrected right front wheel speed being either the first right front wheel speed or the second right front wheel speed. By following the steps described above, the wheel speeds of the left and right front wheels can be corrected while the vehicle is turning, thereby improving the accuracy of wheel speed output. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a velocity decomposition diagram of the wheel rolling process in one embodiment of this application;

[0023] Figure 2 This is a schematic flowchart of a wheel speed correction method provided in one embodiment of this application;

[0024] Figure 3 This is a schematic diagram of the signal interface of the wheel speed correction module during steering provided in one embodiment of this application;

[0025] Figure 4 This is another schematic flowchart of a wheel speed correction method provided in one embodiment of this application;

[0026] Figure 5 This is a wheel angle signal diagram provided in one embodiment of this application;

[0027] Figure 6 This is a wheel speed signal diagram provided in one embodiment of this application;

[0028] Figure 7 This is a diagram showing the result of determining whether a wheel is turning, provided in one embodiment of this application.

[0029] Figure 8This is a comparison diagram of wheel speeds before and after correction provided in one embodiment of this application;

[0030] Figure 9 This is a partially enlarged comparison image of the wheel speed before and after correction provided in one embodiment of this application;

[0031] Figure 10 This is a graph showing the results of determining whether the wheel speed fluctuation before and after correction is too large, provided in one embodiment of this application.

[0032] Figure 11 This is a final revised four-wheel speed diagram provided in one embodiment of this application for subsequent use;

[0033] Figure 12 This is a comparison chart showing the accuracy of yaw rate estimation using wheel speeds before and after correction, provided in one embodiment of this application.

[0034] Figure 13 This is a schematic diagram of the structure of a wheel speed correction device provided in one embodiment of this application;

[0035] Figure 14 This is a schematic diagram of the structure of an electronic device provided in another embodiment of this application. Detailed Implementation

[0036] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0038] Figure 1Decomposing the velocity of a rolling wheel, such as Figure 1 As shown, the speed V at the wheel contact point C It can be calculated according to the following expression:

[0039]

[0040] Wheel sliding speed V relative to the ground s for:

[0041] V s =V C -Ω×r

[0042] Existing algorithms often assume that there is no slippage between the wheel and the ground. s =0, the vehicle speed V is estimated from the wheel speed. veh :

[0043]

[0044] It can be seen that the commonly used estimation method V veh =Ω×r only This holds true when the wheels are not turning. If the wheels are turning, the existing method will introduce errors.

[0045] This application provides a method for correcting wheel speed, which corrects Ω to Ω′, such that... Enhance all V utilization veh The accuracy of the algorithm based on the condition =Ω×r.

[0046] It should be noted that, in this application, wheel speed can also be referred to as rotational speed.

[0047] To address the problems of the prior art, embodiments of this application provide a wheel speed correction method, apparatus, electronic device, medium, and product. The wheel speed correction method provided in this application embodiment will be described first below.

[0048] Figure 2 A schematic flowchart of a wheel speed correction method according to an embodiment of this application is shown. Figure 2 As shown, the wheel speed correction method provided in this application embodiment includes the following steps 101-104, wherein:

[0049] Step 101: While the vehicle is turning, obtain the wheel speeds of the vehicle measured at the current sampling time. The wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed.

[0050] The wheel speed correction method provided in this application can be applied when the vehicle is turning. The process for determining whether the vehicle is turning can be as follows:

[0051] Obtain the first steering wheel angle at the current sampling time and the second steering wheel angle at the previous sampling time; if the absolute value of the difference between the first steering wheel angle and the second steering wheel angle is greater than the second threshold, it is determined that the wheel is turning.

[0052] When the sampling frequency is 100Hz, the second threshold α1 ranges from 1deg to 2deg, corresponding to a steering wheel speed of 100deg / s to 200deg / s. This value can be used to convert the values ​​at different sampling frequencies.

[0053] If the vehicle is turning, the wheel speeds of the left and right front wheels are further corrected. If the vehicle is not turning, that is, the absolute value of the difference between the first steering wheel angle and the second steering wheel angle is less than or equal to the second threshold, no correction is made.

[0054] Step 102: Using the wheel speeds, correct the first left front wheel speed and the first right front wheel speed to obtain the second left front wheel speed and the second right front wheel speed.

[0055] Specifically, the first left front wheel speed and the first right front wheel speed can be corrected using the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed. For example, the first left front wheel speed and the first right front wheel speed can be corrected using the following expression to obtain the second left front wheel speed ω. flm And the second right front wheel speed ω frm :

[0056]

[0057]

[0058] Where, ω fl The first left front wheel speed, ω fr The first right front wheel speed, ω rl The first left rear wheel speed, ω rr δ is the first right rear wheel speed, δ is the first steering wheel angle at the current sampling moment, and n is the steering system transmission ratio.

[0059] Step 103: Based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, determine the corrected left front wheel speed at the current sampling time. The corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed.

[0060] Step 104: Based on the difference between the second right front wheel speed and the right front wheel speed corrected at the previous sampling time, determine the corrected right front wheel speed at the current sampling time. The corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed.

[0061] To ensure the reliability of the corrections for the left and right front wheel speeds, the second left and right front wheel speeds are not directly used as the final determined wheel speeds. Instead, a loopback test is performed before the wheel speeds are output. The second left front wheel speed is compared with the left front wheel speed obtained after correction at the previous sampling time, and the second right front wheel speed is compared with the right front wheel speed obtained after correction at the previous sampling time. If the difference between the wheel speeds at the previous and next sampling times is greater than a first threshold, it indicates that the error in the correction process may be large. To ensure safety, the correction at the current time is abandoned, and the first left front wheel speed or the first right front wheel speed obtained from the initial measurement is directly output.

[0062] Specifically, the corrected left front wheel speed is the final determined left front wheel speed. If the absolute value of the first difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time is less than or equal to a first threshold, then the corrected left front wheel speed is determined to be the second left front wheel speed; if the absolute value of the first difference is greater than the first threshold, then the corrected left front wheel speed is determined to be the first left front wheel speed.

[0063] Accordingly, the corrected right front wheel speed is the final determined right front wheel speed. If the absolute value of the second difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time is less than or equal to the first threshold, then the corrected right front wheel speed is determined to be the second right front wheel speed; if the absolute value of the second difference is greater than the first threshold, then the corrected right front wheel speed is determined to be the first right front wheel speed.

[0064] When the sampling frequency is 100Hz, the first threshold α2 ranges from 5deg / s to 10deg / s, corresponding to a wheel acceleration of 500deg / s. 2 -1000deg / s 2 This can be used to perform conversions at different sampling frequencies.

[0065] In this embodiment, when the vehicle is turning, the method acquires the wheel speeds measured at the current sampling time. These wheel speeds include a first left front wheel speed, a first right front wheel speed, a first left rear wheel speed, and a first right rear wheel speed. Using these wheel speeds, the first left front wheel speed and the first right front wheel speed are corrected to obtain a second left front wheel speed and a second right front wheel speed. Based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, the corrected left front wheel speed at the current sampling time is determined; this corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed. Similarly, based on the difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time, the corrected right front wheel speed at the current sampling time is determined; this corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed. By correcting the wheel speeds of the left and right front wheels while the vehicle is turning, the wheel speeds can be output without the influence of wheel angular velocity, thereby improving the accuracy of wheel speed output and making the relevant algorithms for wheel speed control in the subsequent vehicle chassis control more accurate.

[0066] In one embodiment of this application, step 102, using the wheel speeds, corrects the first left front wheel speed and the first right front wheel speed to obtain the second left front wheel speed and the second right front wheel speed, including steps 1021 and 1022:

[0067] Step 1021: Using the wheel speeds, determine the sum of the front wheel speeds, the difference in the front wheel speeds, the sum of the rear wheel speeds, and the difference in the rear wheel speeds. The sum of the front wheel speeds, the difference in the front wheel speeds, the sum of the rear wheel speeds, and the difference in the rear wheel speeds can be obtained through actual measurement. For example, ω fl +ω fr Let ω be the sum of the front wheel speeds. fl -ω fr For the front wheel speed difference, ω rl +ω rr Let ω be the sum of the rear wheel speeds. rl -ω rr Rear wheel speed difference. ω fl The first left front wheel speed, ω fr The first right front wheel speed, ω rl The first left rear wheel speed, ω rr The first right rear wheel speed.

[0068] Step 1022: Perform a weighted average fusion of the sum of the front wheel speeds, the difference between the front wheel speeds, the sum of the rear wheel speeds, and the difference between the rear wheel speeds to obtain the corrected second left front wheel speed and the second right front wheel speed.

[0069] Based on the principles of kinematics, the following expression can be obtained:

[0070]

[0071]

[0072]

[0073]

[0074] δ is the steering wheel angle at the current sampling moment, n is the steering system transmission ratio, and V x V represents the longitudinal vehicle speed. y The lateral speed is the speed of the vehicle. Let yaw rate be t, wheel track be r, wheel radius be e. KP Let B be a unit vector along the kingpin direction of the tire, and let C be any point on the kingpin. Let C be the center point of the tire contact patch. denoted as , where is the difference between the steering wheel angle at the current sampling time and the steering wheel angle at the previous sampling time, and 'a' is the distance from the vehicle's center of gravity to the front axle.

[0075] Therefore, the ideal sum of front wheel speeds, the difference in front wheel speeds, the sum of rear wheel speeds, and the difference in rear wheel speeds can be obtained as follows:

[0076]

[0077]

[0078]

[0079]

[0080] The ideal first left front wheel speed and the first right front wheel speed are determined according to the following known expressions:

[0081]

[0082]

[0083] In the above, the expression on the right side of the equals sign is used to determine the ideal value, that is, the target value.

[0084] Define the following expression:

[0085] ω fl =ω trans +ω rot

[0086] ω fr =ω trans -ω rot

[0087] Where, ωtrans The wheel speed ω is the speed generated by the lateral and longitudinal vehicle speeds. rot The wheel speed generated by the yaw rate can be obtained from the above expression:

[0088]

[0089]

[0090] Comparing the definitions of wheel speed sum and wheel speed difference mentioned earlier, we can see that wheel speed sum reflects the wheel speed ω generated by the lateral and longitudinal vehicle speeds. trans Wheel speed difference reflects the wheel speed ω generated by the yaw rate. rot Therefore, ω can be expressed using the wheel speed and the difference between wheel speeds. trans With ω rot An estimation is performed. Since both the sum and difference of the front and rear wheel speeds contain measurement errors, a weighted average approach can be used to fuse them. Specifically, the sum of the front wheel speeds, the difference of the front wheel speeds, the sum of the rear wheel speeds, and the difference of the rear wheel speeds are weighted and averaged to obtain the corrected second left front wheel speed ω. flm and the second right front wheel speed ω frm :

[0091] ω flm =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))+(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0092] ω frm =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))-(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0093] Where w1, w2, w3, and w4 are weights.

[0094] Because the rear wheel speed cannot include the projection of the lateral speed onto the front wheel plane. For this item, if the vehicle is a rear-wheel drive vehicle, the rear wheel speed includes the wheel speed due to drive slip. In order to ensure that the fusion of the wheel speeds generated by the lateral and longitudinal vehicle speeds is unbiased, the following expression needs to be satisfied:

[0095] E(w1(ω fl +ω fr )+w2(ω rl +ω rr ))=ω trans

[0096] Solving for w1, we get w1 = 0.5 and w2 = 0. It should be noted that the weights remain unchanged if the vehicle is front-wheel drive or four-wheel drive.

[0097] Since the front wheel speed difference includes additional wheel speed caused by steering, the following expression needs to be satisfied to ensure the unbiasedness of the wheel speed generated by the yaw rate after fusion:

[0098] E(w3(ω fl -ω fr )+w4(ω rl -ω rr ))=ω rot

[0099] Solving for w3, we get w3 = 0.

[0100] In the above, E represents expectation.

[0101] The wheel speed correction method provided in this application is illustrated with the following examples.

[0102] The schematic diagram of the wheel speed correction module interface during steering of the present invention is shown below. Figure 3 As shown. Its inputs are the steering wheel angle δ and the rotational speeds of the four wheels (left front wheel speed ω). fl Right front wheel speed ω fr Left rear wheel speed ω rl Right rear wheel speed ω rr After internal processing by the module, the corrected left front wheel speed ω is output. flmm With the corrected right front wheel speed ω frm .

[0103] The workflow within each cycle of the module is as follows: Figure 4 As shown.

[0104] The first step is to perform differential analysis on the steering wheel angle signal, that is, to perform differential analysis on the steering wheel angle δ at the current moment. k Steering wheel angle δ at the previous moment k-1 The difference is calculated. If the difference is greater than the threshold α1 (when the sampling frequency is 100Hz, the common range of α1 is 1-2 degrees, corresponding to a steering wheel speed of 100-200 degrees; this can be used for conversion at different sampling frequencies), the module determines that the current wheel is turning and corrects the left and right front wheel speeds. Otherwise, no processing is performed, and the original measured wheel speeds ω of the left and right front axles are directly used.fl With ω fr The corrected left front wheel speed ω flm With the right front wheel speed ω frm Output.

[0105] The second step is to correct the speeds of the left front and right front wheels, calculated as follows:

[0106]

[0107]

[0108] This gives the corrected wheel speeds of the left and right front wheels. Here, n is the steering system transmission ratio.

[0109] The derivation of the above formula is described below. Based on the principles of kinematics, the following expression can be obtained:

[0110]

[0111]

[0112]

[0113]

[0114] Among them, V x V represents the longitudinal vehicle speed. y The lateral speed is the speed of the vehicle. yaw rate, δ is the steering wheel angle, n is the steering gear ratio, a is the distance from the center of gravity to the front axle, t is the track width, r is the wheel radius, and e is the yaw rate. KP , like Figure 1 As shown in the image.

[0115] Based on the above formula, the sum of front wheel speeds, the difference in front wheel speeds, the sum of rear wheel speeds, and the difference in rear wheel speeds are as follows:

[0116]

[0117]

[0118]

[0119]

[0120] The ideal front wheel speed should be:

[0121]

[0122]

[0123] Set the following expression:

[0124] ω fl =ω trans +ω rot

[0125] ω fr =ω trans -ω rot

[0126] Where ω trans The wheel speed ω is the speed generated by the lateral and longitudinal vehicle speeds. rot Let the wheel speed be the yaw rate. Then, according to the above expression, we can obtain:

[0127]

[0128]

[0129] Comparing the definitions of wheel speed sum and wheel speed difference mentioned earlier, we can see that wheel speed sum reflects the wheel speed ω generated by the lateral and longitudinal vehicle speeds. trans Wheel speed difference reflects the wheel speed ω generated by the yaw rate. rot Therefore, ω can be expressed using the wheel speed and the difference between wheel speeds. trans With ω rot An estimation is performed. Since both the wheel speeds and their differences between the front and rear wheels have measurement errors, a weighted average approach is needed to fuse them, resulting in the following expression:

[0130] ω flm =ω trans +ω rot =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))+(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0131] ω frm =ω trans -ω rot =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))-(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0132] Where w 1～4 The weights for fusion.

[0133] One fusion method presented in this application, namely the method of setting weights, is that the rear wheel speed cannot include the projection of the lateral vehicle speed onto the front wheel plane. In this embodiment, the object is a rear-wheel drive vehicle, and the rear wheel speeds include the wheel speeds caused by drive slip. Therefore, to ensure that the rear wheel speed fusion is unbiased, the following expression must be satisfied:

[0134] E(w1(ω fl +ω fr )+w2(ω rl +ω rr ))=ω trans

[0135] Solving for w1, we get w1 = 0.5 and w2 = 0. It should be noted that the weights remain unchanged for front-wheel or four-wheel drive systems.

[0136] Since the front wheel speed difference includes additional wheel speed caused by steering, the following expression must be satisfied to ensure the unbiasedness after fusion:

[0137] E(w3(ω fl -ω fr )+w4(ω rl -ω rr ))=ω rot

[0138] Solving for w3, we get w3 = 0.

[0139] The result of this fusion is:

[0140]

[0141]

[0142] This refers to the wheel speed correction expression derived earlier.

[0143] Finally, since the correction method implicitly involves a loop process of first subtracting the wheel speed difference caused by the different turning radii of the inner and outer sides, and then adding back the wheel speed difference caused by the different turning radii of the inner and outer sides, a loop check is performed before the final output to ensure reliability. That is, the wheel speeds ω of the corrected left and right front wheels are checked. flm With ω frm Compared to the previous moment ω flm With ω frm For comparison, since wheel speed cannot change abruptly, if the difference in wheel speed between two consecutive moments is greater than α2 (when the sampling frequency is 100Hz, the common range of α2 is 5-10 degrees Celsius, corresponding to a wheel acceleration of 500 degrees Celsius), then the wheel speed will be affected. 2 -1000deg / s 2(This can be converted based on different sampling frequencies). If the error is too large during the correction process, then to ensure safety, the correction should be abandoned and the wheel speeds ω of the left and right front axles measured by the original sensor should be used. fl With ω fr Output directly.

[0144] The wheel speed correction method provided in this application can remove the additional wheel speed caused by the wheel turning from the original wheel speed signal, making the results obtained by the subsequent vehicle speed estimation algorithm more accurate. Specifically, the method in this application relies only on the steering system reduction ratio, a specific structural parameter that is easily obtained. This reduces the calibration workload when matching the algorithm to a real vehicle and makes it less susceptible to parameter disturbances caused by different operating conditions, resulting in strong robustness. Furthermore, besides the original wheel speed signal, the algorithm only requires the signal from a common sensor such as the steering wheel angle sensor, making it low-cost, safe, reliable, and easy to upgrade to existing architectures. In addition, to ensure safety and robustness, a loop closure detection method is designed based on wheel rotation dynamics to ensure that the error of the aforementioned fusion result is within an acceptable range.

[0145] It should be noted that this method is not limited to four-wheeled passenger cars; multi-axle vehicles with non-all-axle steering or construction machinery can also use this method to correct the wheel speed of the steering wheels. Furthermore, the sensor solution used in this method is only one of several options; the steering wheel angle sensor can be replaced by a wheel angle sensor, power steering motor angle sensor, or any other measurement solution that can be used to determine whether steering is in progress and calculate the wheel angle.

[0146] The following specific embodiments illustrate the wheel speed correction method provided in this application.

[0147] The following example illustrates the specific implementation of the wheel speed signal correction method proposed in this invention, using the application of this algorithm in a passenger vehicle as a concrete example. The object of this embodiment is a front-axle steering, rear-wheel drive family sedan. Initially, it travels in a straight line at a constant speed of 5 km / h. At the 47th second, a step input is applied to the steering wheel, and the vehicle begins to turn. The original wheel speed signal measured during the above experiment is as follows: Figure 5 Wheel angle signal, such as Figure 6 It can be seen that from the 47th to the 53rd second, when the front wheels are turning, the wheel speed fluctuates, and the left and right front wheels change speeds in opposite directions. This is the additional wheel speed caused by turning mentioned in this invention. Next, the wheel speed measured in this experiment is corrected according to the correction method proposed in this invention.

[0148] First, the steering wheel angle is differentially calculated, and its absolute value is checked to see if it is greater than 2 degrees. The result is as follows: Figure 7Where 1 represents true and 0 represents false. If the result is true from the 47th to the 53rd second, the subsequent correction steps continue; otherwise, if the result is false, the calculation for the current cycle ends directly.

[0149] The first step of the correction is to calculate the average wheel speed of the left and right front wheels. The second step is to multiply the difference in wheel speed between the left and right rear wheels by the cosine of the front wheel angle derived from the steering wheel angle, and then add or subtract this product from the average wheel speed of the left and right front wheels obtained in the first step (add for the left front wheel, subtract for the right front wheel). The correction result is as follows. Figure 8 and Figure 9 As shown.

[0150] Finally, it was determined whether the difference between the corrected result and the wheel speed at the previous moment was too large, exceeding 10 deg / s. The result was as follows: Figure 10 If all values ​​are false, the wheel speed correction result will be output normally. The final wheel speed correction result is as follows: Figure 11 .

[0151] To illustrate the significance of this wheel speed correction, the vehicle's yaw rate is calculated using the wheel speeds before and after correction, and compared with the measured values ​​from the yaw rate sensor. Figure 11 As shown, it is evident that the yaw rate estimation accuracy will significantly decrease if wheel speed is not corrected during steering. After correction using the method of this invention, the estimation accuracy is significantly improved, and the estimation accuracy during non-steering conditions remains unchanged, indicating that the method is effective and beneficial for high-precision vehicle motion state estimation based on wheel speed.

[0152] Figure 13 A structural diagram of the wheel speed correction device provided in an embodiment of this application is shown. Figure 13 As shown, the wheel speed correction device 400 includes:

[0153] The first acquisition module 401 is used to acquire the wheel speeds of the vehicle measured at the current sampling time when the vehicle is turning. The wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed.

[0154] Correction module 402 is used to correct the first left front wheel speed and the first right front wheel speed using the wheel speed to obtain the second left front wheel speed and the second right front wheel speed;

[0155] The first determining module 403 is used to determine the corrected left front wheel speed at the current sampling time based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, wherein the corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed.

[0156] The second determining module 404 is used to determine the corrected right front wheel speed at the current sampling time based on the difference between the second right front wheel speed and the right front wheel speed corrected at the previous sampling time, wherein the corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed.

[0157] Optionally, the correction module 402 includes:

[0158] The first determining submodule is used to determine the sum of front wheel speeds, the difference between front wheel speeds, the sum of rear wheel speeds, and the difference between rear wheel speeds using the wheel speeds of the wheels.

[0159] The correction submodule is used to perform a weighted average fusion of the sum of the front wheel speeds, the difference between the front wheel speeds, the sum of the rear wheel speeds, and the difference between the rear wheel speeds to obtain the corrected second left front wheel speed and the second right front wheel speed.

[0160] Optionally, the correction submodule is used to perform a weighted average fusion of the sum of the front wheel speeds, the difference in the front wheel speeds, the sum of the rear wheel speeds, and the difference in the rear wheel speeds to obtain the corrected second left front wheel speed ω. flm and the second right front wheel speed ω frm :

[0161] ω flm =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))+(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0162] ω frm =(w1(ω) fl +ω fr )+w2(ω rl +ω rr ))-(w3(ω fl -ω fr )+w4(ω rl -ω rr ))

[0163] Where w1, w2, w3, and w4 are weights, and ω fl The first left front wheel speed, ω fr The first right front wheel speed, ω rl The first left rear wheel speed, ω rr The first right rear wheel speed.

[0164] Alternatively, the values ​​of w1, w2, w3, and w4 are determined according to the following expression:

[0165] E(w1(ω fl +ω fr )+w2(ω rl +ω rr ))=ω trans

[0166] E(w3(ω fl -ω fr )+w4(ω rl -ω rr ))=ω rot

[0167] in,

[0168]

[0169]

[0170] E represents expectation.

[0171] Optionally, the correction module 402 is used to correct the first left front wheel speed and the first right front wheel speed using the following expression to obtain the second left front wheel speed ω. flm And the second right front wheel speed ω frm :

[0172]

[0173]

[0174] Where, ω fl The first left front wheel speed, ω fr The first right front wheel speed, ω rl The first left rear wheel speed, ω rr δ is the first right rear wheel speed, δ is the first steering wheel angle at the current sampling moment, and n is the steering system transmission ratio.

[0175] Optionally, the first determining module 403 is used to determine the corrected left front wheel speed as the second left front wheel speed if the absolute value of the first difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time is less than or equal to a first threshold.

[0176] If the absolute value of the first difference is greater than the first threshold, then the corrected left front wheel speed is determined to be the first left front wheel speed;

[0177] The second determining module 404 is used to determine the corrected right front wheel speed as the second right front wheel speed if the absolute value of the second difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time is less than or equal to a first threshold.

[0178] If the absolute value of the second difference is greater than the first threshold, then the corrected right front wheel speed is determined to be the first right front wheel speed.

[0179] Optionally, the device further includes: a second acquisition module, used to acquire the first steering wheel angle at the current sampling time and the second steering wheel angle at the previous sampling time;

[0180] The determination module is used to determine that the vehicle is turning if the absolute value of the difference between the first steering wheel angle and the second steering wheel angle is greater than a second threshold.

[0181] The wheel speed correction device 400 provided in this application embodiment can realize all the processes implemented in the aforementioned wheel speed correction method embodiment and achieve the same technical effect. To avoid repetition, it will not be described again here.

[0182] Figure 14 A schematic diagram of the hardware structure of the wheel speed correction method provided in an embodiment of this application is shown.

[0183] An electronic device may include a processor 601 and a memory 602 storing computer program instructions.

[0184] Specifically, the processor 601 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0185] Memory 602 may include mass storage for data or instructions. For example, and not limitingly, memory 602 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 602 may include removable or non-removable (or fixed) media. Where appropriate, memory 602 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 602 is non-volatile solid-state memory.

[0186] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to the first aspect of this disclosure.

[0187] The processor 601 reads and executes computer program instructions stored in the memory 602 to implement any of the wheel speed correction methods in the above embodiments.

[0188] In one example, the electronic device may also include a communication interface 603 and a bus 610. For example, Figure 14 As shown, the processor 601, memory 602, and communication interface 603 are connected through bus 610 and complete communication with each other.

[0189] The communication interface 603 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0190] Bus 610 includes hardware, software, or both, that couples the components of the wheel speed correction method together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 610 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0191] Furthermore, in conjunction with the wheel speed correction methods in the above embodiments, this application embodiment can provide a computer-readable storage medium for implementation. This computer-readable storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the wheel speed correction methods in the above embodiments.

[0192] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0193] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0194] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0195] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0196] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for correcting wheel speed, characterized in that, The method includes: While the vehicle is turning, the wheel speeds of the vehicle measured at the current sampling time are obtained, and the wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed. Using the wheel speeds, the first left front wheel speed and the first right front wheel speed are corrected to obtain the second left front wheel speed and the second right front wheel speed; Based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, the corrected left front wheel speed at the current sampling time is determined, wherein the corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed. Based on the difference between the second right front wheel speed and the right front wheel speed corrected at the previous sampling time, the corrected right front wheel speed at the current sampling time is determined, wherein the corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed. Using the wheel speeds, the first left front wheel speed and the first right front wheel speed are corrected to obtain the second left front wheel speed and the second right front wheel speed, including: using the wheel speeds to determine the sum of front wheel speeds, the difference between front wheel speeds, the sum of rear wheel speeds, and the difference between rear wheel speeds; and performing a weighted average fusion of the sum of front wheel speeds, the difference between front wheel speeds, the sum of rear wheel speeds, and the difference between rear wheel speeds to obtain the corrected second left front wheel speed and the second right front wheel speed.

2. The method according to claim 1, characterized in that, The step of weighted averaging and fusing the sum of the front wheel speeds, the difference in the front wheel speeds, the sum of the rear wheel speeds, and the difference in the rear wheel speeds to obtain the corrected second left front wheel speed and second right front wheel speed includes: The weighted average of the sum of the front wheel speeds, the difference in the front wheel speeds, the sum of the rear wheel speeds, and the difference in the rear wheel speeds is fused to obtain the corrected second left front wheel speed. and the second right front wheel speed : in, , , , As weight, , The first right front wheel speed, , The first right rear wheel speed.

3. The method according to claim 2, characterized in that, , , , The value is determined by the following expression: in, E represents expectation. The wheel speed is generated by the lateral and longitudinal vehicle speeds. The wheel speed generated by the yaw rate. The steering wheel angle at the current sampling time is... This refers to the steering system gear ratio. For longitudinal vehicle speed, The lateral speed is the speed of the vehicle. The yaw rate is... For wheel moment, The radius is the wheel radius.

4. The method according to claim 1, characterized in that, Alternatively, the step of using the wheel speeds of the first left front wheel and the first right front wheel to correct the first left front wheel speed and the second right front wheel speed includes: The second left front wheel speed is obtained by correcting the first left front wheel speed and the first right front wheel speed using the following expression. and the second right front wheel speed : in, , The first right front wheel speed, , The first right rear wheel speed, The first steering wheel angle at the current sampling time. This is the steering system transmission ratio.

5. The method according to claim 1, characterized in that, The step of determining the corrected left front wheel speed at the current sampling time based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time includes: If the absolute value of the first difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time is less than or equal to the first threshold, then the corrected left front wheel speed is determined to be the second left front wheel speed. If the absolute value of the first difference is greater than the first threshold, then the corrected left front wheel speed is determined to be the first left front wheel speed; The step of determining the corrected right front wheel speed at the current sampling time based on the difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time includes: If the absolute value of the second difference between the second right front wheel speed and the corrected right front wheel speed at the previous sampling time is less than or equal to the first threshold, then the corrected right front wheel speed is determined to be the second right front wheel speed. If the absolute value of the second difference is greater than the first threshold, then the corrected right front wheel speed is determined to be the first right front wheel speed.

6. The method according to claim 1, characterized in that, Before obtaining the wheel speeds of the vehicle while it is turning, the method further includes: Obtain the first steering wheel angle at the current sampling time and the second steering wheel angle at the previous sampling time; If the absolute value of the difference between the first steering wheel angle and the second steering wheel angle is greater than the second threshold, it is determined that the vehicle is turning.

7. A wheel speed correction device, characterized in that, The device includes: The first acquisition module is used to acquire the wheel speeds of the vehicle measured at the current sampling time when the vehicle is turning. The wheel speeds include the first left front wheel speed, the first right front wheel speed, the first left rear wheel speed, and the first right rear wheel speed. The correction module is used to correct the first left front wheel speed and the first right front wheel speed using the wheel speed to obtain the second left front wheel speed and the second right front wheel speed. The first determining module is used to determine the corrected left front wheel speed at the current sampling time based on the difference between the second left front wheel speed and the corrected left front wheel speed at the previous sampling time, wherein the corrected left front wheel speed is either the first left front wheel speed or the second left front wheel speed. The second determining module is used to determine the corrected right front wheel speed at the current sampling time based on the difference between the second right front wheel speed and the right front wheel speed corrected at the previous sampling time, wherein the corrected right front wheel speed is either the first right front wheel speed or the second right front wheel speed. The correction module includes: a determination submodule, used to determine the sum of front wheel speeds, the difference between front wheel speeds, the sum of rear wheel speeds, and the difference between rear wheel speeds using the wheel speeds; and a correction submodule, used to perform a weighted average fusion of the sum of front wheel speeds, the difference between front wheel speeds, the sum of rear wheel speeds, and the difference between rear wheel speeds to obtain the corrected second left front wheel speed and the second right front wheel speed.

8. An electronic device, characterized in that, The device includes a processor and a memory storing computer program instructions, wherein the processor, when executing the computer program instructions, implements the method as described in any one of claims 1-6.

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