Dual-rudder parameter calibration method, device and equipment and storage medium

Abstract

The application discloses a double-steering-wheel parameter calibration method and device, equipment and a storage medium, and relates to mobile robot technology. The second steering wheel included in the target vehicle is placed at zero position, and first pose data detected by an encoder of the first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle are acquired during driving of the target vehicle according to a preset track. Based on the correlation between the first pose data and the third pose data, the values of the to-be-calibrated parameters of the first steering wheel and the external parameters of the guiding device relative to the center of the universal wheel are determined, and the center of the universal wheel is determined based on the positions of the first steering wheel and the second steering wheel in the target vehicle. Based on the values of the to-be-calibrated parameters of the first steering wheel and the correlation between the first pose data and the second pose data, the values of the to-be-calibrated parameters of the second steering wheel are determined, so that the parameters of the double steering wheels are calibrated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mobile robots, and provides a double-steering-wheel parameter calibration method, device, equipment and storage medium. BACKGROUND

[0002] An automated guided vehicle (AGV) is also commonly known as an AGV trolley. The driving mode of the AGV trolley can be divided into differential wheel driving, single-steering-wheel driving and double-steering-wheel driving. Compared with single-steering-wheel driving, double-steering-wheel driving is more flexible in complex dynamic environments. One of the keys to achieving high-precision servo movement planning control for an AGV trolley based on double-steering-wheel driving is double-steering-wheel parameter calibration.

[0003] At present, in the double-steering-wheel calibration process, the front steering wheel and the rear steering wheel are controlled to be at a set rotation angle, and move forward or backward at the same speed. If the movement trajectory of the vehicle body deflects clockwise, the rotation angles of the front and rear steering wheels are adjusted counterclockwise by the same angle. If the movement trajectory of the vehicle body deflects counterclockwise, the rotation angles of the front and rear steering wheels are adjusted clockwise by the same angle. After the movement trajectory is not deflected, the current positions of the steering wheels are taken as zero points for the deflection adjustment of the front and rear steering wheels. However, the method of adjusting the steering wheels based on the clockwise deflection of the vehicle body and the counterclockwise adjustment cannot be generalized, and is a deflection adjustment method based on experience. Moreover, the method only calibrates the steering wheel zero deflection of the double-steering-wheel, and the steering wheel radius and other parameters cannot be calibrated by the method.

[0004] Therefore, there is no effective solution to the calibration of various parameters of the double-steering-wheel in the related art. SUMMARY

[0005] Embodiments of the present application provide a double-steering-wheel parameter calibration method, device, equipment and storage medium, which are used to calibrate various parameters of the double-steering-wheel.

[0006] In one aspect, a double-steering-wheel parameter calibration method is provided, and the method comprises:

[0007] The second steering wheel included in the target vehicle is placed at zero position, and first pose data detected by an encoder of the first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle are acquired during driving of the target vehicle according to a preset trajectory; wherein the preset trajectory is a non-straight trajectory;

[0008] Based on the correlation between the first pose data and the third pose data, the values of various to-be-calibrated parameters of the first steering wheel and the external parameters of the guiding device relative to the center of the universal wheel are determined, and the center of the universal wheel is determined based on the positions of the first steering wheel and the second steering wheel in the target vehicle.

[0009] determine the values of the to-be-calibrated parameters of the second steering wheel based on the values of the to-be-calibrated parameters of the first steering wheel and the correlation between the first pose data and the second pose data.

[0010] In one aspect, a device for calibrating parameters of a double steering wheel is provided, and the device comprises:

[0011] a data acquisition unit configured to place a second steering wheel included in a target vehicle at zero position, and acquire first pose data detected by an encoder of a first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle during driving of the target vehicle along a preset trajectory, wherein the preset trajectory is a non-straight trajectory;

[0012] a first calculation unit configured to determine values of to-be-calibrated parameters of the first steering wheel and an external parameter of the guiding device relative to a center of a universal wheel based on a correlation between the first pose data and the third pose data, wherein the center of the universal wheel is determined based on positions of the first steering wheel and the second steering wheel in the target vehicle;

[0013] a second calculation unit configured to determine values of to-be-calibrated parameters of the second steering wheel based on the values of the to-be-calibrated parameters of the first steering wheel and the correlation between the first pose data and the second pose data.

[0014] Optionally, the preset path comprises:

[0015] a first path, the first path being a path in which the first steering wheel travels for a first time duration after being adjusted by a first angle in a first direction, the first direction being any one of clockwise or counterclockwise;

[0016] a second path, the second path being a path in which the first steering wheel travels for a second time duration after being returned to zero from the first angle;

[0017] a third path, the third path being a path in which the first steering wheel travels for the first time duration after being adjusted by the first angle in a second direction, the second direction being an opposite direction of the first direction.

[0018] Optionally, the first pose data comprises a first rotation speed and a first rotation angle of the first steering wheel at each detection time, and the third pose data comprises a deflection angle at each detection time and position information at each detection time.

[0019] The first calculation unit is specifically configured to:

[0020] determine a zero offset angle of the first steering wheel based on the first rotation speed, the first rotation angle and the deflection angle, with a constraint that a first rotation angle corresponding to the first steering wheel is equal to a third rotation angle corresponding to the guide device;

[0021] determine a displacement vector between each two adjacent detection moments of the guide device based on position information corresponding to each two adjacent detection moments;

[0022] determine a first wheelbase between the first steering wheel and the center of the universal wheel and an extrinsic parameter of the guide device based on a correlation between each obtained displacement vector and a displacement vector corresponding to the first steering wheel;

[0023] determine a radius of the first steering wheel based on the wheelbase and the zero offset angle.

[0024] Optionally, the first computing unit is specifically configured to:

[0025] determine a third rotation angle of the guide device between each two adjacent moments based on the deflection angle by using a least square iteration method;

[0026] determine the zero offset angle based on the first rotation speed, the first rotation angle and the third rotation angle, with a constraint that the first rotation angle is equal to the third rotation angle.

[0027] Optionally, the first computing unit is specifically configured to:

[0028] construct a least square equation based on the wheelbase and the extrinsic parameter, with a constraint that each displacement vector is equal to the displacement vector corresponding to the first steering wheel;

[0029] solve the least square equation to obtain the first wheelbase and the extrinsic parameter.

[0030] Optionally, the first pose data includes a second rotation angle of the second steering wheel at each detection moment.

[0031] The second computing unit is specifically configured to:

[0032] determine a radius of the second steering wheel and a second wheelbase between the second steering wheel and the center of the universal wheel based on the first rotation speed, the first rotation angle and the radius of the first steering wheel, the second rotation angle, and a constraint that a mileage of the first steering wheel is equal to a mileage of the second steering wheel.

[0033] Optionally, the second computing unit is specifically configured to:

[0034] for any two adjacent detection moments in the preset track, perform the following operations:

[0035] determine a displacement amount of the first rudder before the two adjacent detection moments based on the first rotation speed, the first rotation angle and the radius of the first rudder at the two adjacent detection moments;

[0036] determine a rotation radius of the first rudder at the two adjacent detection moments based on the first wheelbase and a rotation angle of the first rudder at a previous moment of the two adjacent detection moments;

[0037] determine a displacement amount change rate of the first rudder based on a ratio between the obtained displacement amount and the rotation radius;

[0038] construct an equation based on the second wheelbase and the radius of the second rudder based on the obtained displacement amount change rate, the first wheelbase and the second rotation angle;

[0039] solve the equation to obtain the second wheelbase and the radius of the second rudder.

[0040] In an aspect, a computer device is provided, including a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of any of the above methods when executing the computer program.

[0041] In an aspect, a computer storage medium is provided, having computer program instructions stored thereon, the computer program instructions being executed by a processor to implement the steps of any of the above methods.

[0042] In an aspect, a computer program product or computer program is provided, including computer instructions stored in a computer readable storage medium. A processor of a computer device reads the computer instructions from the computer readable storage medium, and the processor executes the computer instructions to cause the computer device to perform the steps of any of the above methods.

[0043] In the embodiment of the present application, the second steering wheel included in the target vehicle is placed at zero position, and the first pose data detected by the encoder of the first steering wheel, the second pose data detected by the encoder of the second steering wheel and the third pose data detected by the guide device are acquired during the driving of the target vehicle according to the preset trajectory, and then the correlation between the first pose data and the third pose data is used to determine the to-be-calibrated parameter values of the first steering wheel and the external parameters of the guide device relative to the center of the universal wheel, and the correlation between the first pose data and the second pose data is used to determine the to-be-calibrated parameter values of the second steering wheel based on the to-be-calibrated parameter values of the first steering wheel. In the embodiment of the present application, the second steering wheel is placed at zero position, so that the zero offset angle of the second steering wheel does not need to be calibrated, the efficiency of calibration is improved, and the whole double-steering wheel calibration is ingeniously converted into single-steering wheel calibration, and then the parameters of the second steering wheel can be solved based on the correlation between the pose data of the front and rear steering wheels after the parameters of the first steering wheel are solved, so as to realize the parameter calibration of the double-steering wheel. BRIEF DESCRIPTION OF DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technical solutions, the drawings needed to be used in the embodiments or the related technical solution description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor based on the provided drawings.

[0045] Figure 1 The application scenario provided for the embodiments of the present application is shown in the figure;

[0046] Figure 2 The vehicle body model of the target vehicle provided for the embodiments of the present application is shown in the figure;

[0047] Figure 3 The flowchart of the double-steering wheel parameter calibration provided for the embodiments of the present application is shown in the figure;

[0048] Figure 4 The schematic diagram of a possible motion trajectory provided for the embodiments of the present application is shown in the figure;

[0049] Figure 5 The principle diagram for solving the related parameters of the second steering wheel provided for the embodiments of the present application is shown in the figure;

[0050] Figure 6 The flowchart of the calibration process provided for the embodiments of the present application is shown in the figure;

[0051] Figure 7 The structure diagram of the double-steering wheel parameter calibration device provided for the embodiments of the present application is shown in the figure;

[0052] Figure 8 The structure diagram of the computer device provided for the embodiments of the present application is shown in the figure;

[0053] Figure 9 Another structural schematic diagram of a computer device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0054] For the purpose, technical solutions and advantages of the present application to be clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application. The embodiments in the present application and the features in the embodiments can be combined with each other in a non-conflicting manner. Moreover, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0055] For the purpose, technical solutions and advantages of the present application to be clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application. The embodiments in the present application and the features in the embodiments can be combined with each other in a non-conflicting manner. Moreover, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in an order different from that shown here.

[0056] AGV: or mobile robot, can include equipped with electromagnetic or optical automatic navigation device, can travel along the specified navigation path, with safety protection and various transfer functions of the transport trolley.

[0057] Steering wheel: or drive wheel, used to drive the vehicle movement. Generally speaking, the driving mode of AGV can include differential wheel drive, single steering wheel drive and double steering wheel drive. Compared with single steering wheel drive mode, double steering wheel has higher degree of freedom and more complex model, so the parameter calibration is more complex. Taking double steering wheel as an example, it contains two steering wheels, which can be deployed according to the demand of double steering wheel position, such as the diagonal position of the vehicle body, such as the upper left corner and the lower right corner. In subsequent use, the parameters of the two steering wheels need to be based on to control the movement of the vehicle body, so the parameters need to be accurately calibrated.

[0058] The design idea of the embodiments of the present application will be briefly introduced as follows:

[0059] At present, in the calibration process of the double rudders, the front rudder and the rear rudder can be controlled to be at a set rotation angle and move forward or backward at the same rotation speed. If the movement trajectory of the vehicle body deflects clockwise, the rotation angle of the front rudder and the rear rudder is adjusted counterclockwise by the same angle. If the movement trajectory of the vehicle body deflects counterclockwise, the rotation angle of the front rudder and the rear rudder is adjusted clockwise by the same angle. After the movement trajectory is not deflected, the current positions of the rudders are taken as zero points for the deflection adjustment of the front rudder and the rear rudder. However, the method cannot be generalized, which is an empirical deflection adjustment method. Moreover, the method only calibrates the zero deflection of the double rudders, and parameters such as the rudder radius cannot be calibrated by the method.

[0060] Therefore, the embodiment of the present application provides a double rudder parameter calibration method. In the method, the second rudder included in the target vehicle is placed at zero position. First pose data detected by an encoder of the first rudder, second pose data detected by an encoder of the second rudder, and third pose data detected by a guide device are obtained during movement of the target vehicle according to a preset trajectory. Then, based on the correlation between the first pose data and the third pose data, the values of the to-be-calibrated parameters of the first rudder and the external parameters of the guide device relative to the center of the universal wheel are determined. Based on the values of the to-be-calibrated parameters of the first rudder and the correlation between the first pose data and the second pose data, the values of the to-be-calibrated parameters of the second rudder are determined. In the embodiment of the present application, the second rudder is placed at zero position, so that the zero deflection angle of the second rudder does not need to be calibrated, the efficiency of calibration is improved, and the double rudder calibration is ingeniously converted into single rudder calibration. Then, the parameters of the second rudder are solved based on the correlation between the pose data of the front rudder and the rear rudder after the parameters of the first rudder are solved, so as to realize the parameter calibration of the double rudder.

[0061] In addition, in the calibration of the parameters of the first rudder and the external parameters of the guide device, the zero deflection angle of the first rudder is solved by rotation constraint, and then the radius and the wheelbase of the first rudder and the external parameters of the guide device are solved based on translation constraint. Finally, the parameters of the second rudder are solved based on the displacement constraint between the first rudder and the second rudder, so as to realize the parameter calibration of the double rudder.

[0062] The application scenarios to which the technical solution of the embodiment of the present application can be applied will be briefly introduced below. It should be noted that the following application scenarios are only used to illustrate the embodiment of the present application but not to limit. In the specific implementation process, the technical solution provided by the embodiment of the present application can be flexibly applied according to actual needs.

[0063] The scheme provided by the embodiment of the present application can be applied to most double rudder based vehicle parameter calibration scenarios, such as the double rudder parameter calibration of the AGV small car mentioned above.

[0064] like Figure 1 The diagram shown is an application scenario provided by an embodiment of this application. In this scenario, a calibration device 101 and a vehicle to be calibrated 102 may be included.

[0065] The calibration device 101 can be any computer device with a certain computing capability, such as a mobile phone, tablet computer (PAD), laptop computer, desktop computer, smart TV, smart in-vehicle device, smart wearable device, and server. The server can be a standalone physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms, but is not limited to these. The vehicle to be calibrated 102 is any vehicle using a dual-steering wheel drive system, which includes at least two steering wheels and a guidance device.

[0066] It should be noted that the dual-steering wheel calibration method in this application embodiment can be executed by the calibration device 101 or the vehicle 102 to be calibrated alone, or by the vehicle 102 to be calibrated and the calibration device 101 together. For example, the vehicle 102 to be calibrated can place its second steering wheel in the zero position and drive according to a preset trajectory, collecting the first pose data detected by the encoder of the first steering wheel, the second pose data detected by the encoder of the second steering wheel, and the third pose data detected by the guidance device, and then perform parameter calibration based on the collected data using the method of this application embodiment. Alternatively, the calibration device 101 can execute the method. For example, the calibration device 101 can control the vehicle 102 to be calibrated to place the second steering wheel in the zero position and send driving parameters to the vehicle 102 to be calibrated according to a preset trajectory, and receive the first pose data, second pose data, and third pose data sent by the vehicle 102 to be calibrated, and then perform parameter calibration based on the collected data using the method of this application embodiment. Alternatively, the vehicle to be calibrated 102 can place its second steering wheel in the zero position and drive along a preset trajectory, collecting first, second, and third pose data, which are then sent to the calibration device 101. The calibration device 101 then performs calculations based on this data. This application does not impose specific limitations here; the following explanation mainly uses the calibration device 101 as an example.

[0067] Taking the calibration device 101 as an example, the calibration device 101 can include one or more processors, memories, I / O interfaces for interacting with terminals, and the like. The memories can further store program instructions of the double-steering wheel parameter calibration method provided in the embodiments of the present application, which can be executed by the processors to implement the steps of the double-steering wheel parameter calibration method provided in the embodiments of the present application, so as to implement the parameter calibration process of the double-steering wheel.

[0068] In the embodiments of the present application, the calibration device 101 and the vehicle to be calibrated 102 can be directly or indirectly connected through one or more networks 103. The network 103 can be a wired network or a wireless network. For example, the wireless network can be a mobile cellular network or a wireless fidelity (WIFI) network. Of course, the network can also be other possible networks, and the embodiments of the present application do not limit the network.

[0069] It should be noted that, Figure 1 It should be noted that,

[0070] The double-steering wheel parameter calibration method provided in the exemplary embodiments of the present application will be described below in combination with the application scenarios described above and with reference to the accompanying drawings. It should be noted that the above-mentioned application scenarios are only shown to facilitate the understanding of the spirit and principles of the present application, and the embodiments of the present application are not limited in this respect.

[0071] Before introducing the method flow, the vehicle body model of the calibration target vehicle required in the embodiments of the present application will be introduced first. Referring to Figure 2 The vehicle body model of the target vehicle is shown in the figure, which is specifically shown by taking the steering wheels at the upper left corner and the lower right corner as examples, i.e., A1 is the front steering wheel and A2 is the rear steering wheel, but the positions of the two steering wheels are not limited in the actual scenario.

[0072] For the double-steering wheel, the forward direction of the vehicle body is defined first, referring to Figure 2 The forward direction is defined as the direction of the second steering wheel, i.e., the A2 steering wheel, when the steering wheels are reset. The WA2 line segment (herein, the line segment between the center point of A2 and the universal wheel center W) is perpendicular to the forward direction of A2, and the line connecting the front steering wheel center A1 and W is perpendicular to WA2. The position and uniqueness of W can be determined according to the above two conditions. The vehicle body mileage center O is the intersection of the perpendicular bisectors of WA1 and WA2. Figure 2The middle Laser represents a guiding device, which is specifically shown by laser navigation as the guiding device in this embodiment, and the following embodiments are also specifically described by taking laser navigation as an example, but it should be noted that other possible guiding devices can also be used in actual applications, and the embodiments of the present application do not limit this.

[0073] Therefore, in the embodiments of the present application, the quantities required for calibration of the double steering wheels are as follows:

[0074] (1) The radius r of the steering wheel A1 A1 .

[0075] (2) The zero offset angle θ of the steering wheel A1 relative to the forward direction when the steering wheel A1 is at zero position offA1 .

[0076] (3) The wheelbase b of the steering wheel A1 from the center W of the universal wheel.

[0077] (4) The radius r of the steering wheel A2 A2 .

[0078] (5) The wheelbase a of the steering wheel A2 from the center W of the universal wheel.

[0079] (6) The external parameters (x o_l y o_l θ o_l ) of the laser relative to the center W of the universal wheel, x o_l and y o_l are the coordinates of the guiding device relative to the center W of the universal wheel, and θ o_l is the angle of the guiding device relative to the center W of the universal wheel.

[0080] It should be noted that in the embodiments of the present application, the zero offset of the steering wheel A2 relative to the forward direction when the steering wheel A2 is at zero position is 0 by definition, and therefore does not need to be calibrated. When b and a are known, the external parameters of the laser relative to W can be converted to parameters in the coordinate system relative to the center O of the odometer, and therefore only the external parameters of the laser relative to W need to be calibrated.

[0081] Referring to FIG. 1, a flowchart of a double steering wheel parameter calibration method provided by the embodiments of the present application is shown, and the specific implementation process of the method is as follows: Figure 3

[0082] Step 301: Place the second steering wheel A2 included in the target vehicle at zero position, and obtain first pose data detected by an encoder of the first steering wheel A1, second pose data detected by an encoder of the second steering wheel A2, and third pose data detected by a guiding device during driving of the target vehicle according to a preset trajectory.

[0083] The preset trajectory is a non-straight trajectory, in other words, the preset trajectory includes a path that rotates relative to the forward direction, and the forward direction is the direction pointed to by the second steering wheel when the second steering wheel is at zero position.​

[0084] In one possible implementation, the preset trajectory can be adopted as follows: Figure 4 The trajectory shown specifically includes three paths:

[0085] (1) The first path is the trajectory obtained by adjusting the first angle along the first direction and traveling for the first duration. The first direction is either clockwise or counterclockwise.

[0086] For example, see Figure 4 As shown, by returning the second steering wheel A2 to position 0 and adjusting the first steering wheel A1 to turn 45 degrees to the left, after traveling for a period of time, the following can be obtained: Figure 4 The arc trajectory AB around O1.

[0087] (2) The second path is the trajectory obtained after the first steering wheel A1 returns to zero from the first angle and travels for a second duration.

[0088] For example, see Figure 4 As shown, the first steering wheel A1 is adjusted from 45 degrees to the left to zero. After traveling for a period of time, the following is obtained: Figure 4 The straight-line trajectory BC in the diagram.

[0089] (3) The third path is to adjust the first steering wheel A1 along the second direction at the first angle and travel for the first time. The second direction is the opposite of the first direction. For example, if the first direction is counterclockwise, then the second direction can be clockwise.

[0090] For example, see Figure 4 As shown, after adjusting the first steering wheel A1 to turn 45 degrees to the right and traveling for a period of time, the following is obtained: Figure 4 The arc trajectory CD around O2.

[0091] In one possible implementation, parameters such as the angle of the steering wheel and the speed of travel at each moment in the preset trajectory can be sent to the target vehicle in advance. The target vehicle can then move according to the given preset parameters, and the corresponding pose data during the process can be collected by the encoder of the steering wheel and the laser.

[0092] In another possible implementation, parameters can be sent to the target vehicle in real time. For example, the target vehicle can be instructed to move according to the open-loop speed. Figure 4 The vehicle travels in three segments, and because it operates at an open-loop speed, it does not need to strictly track the trajectory of the target vehicle.

[0093] It should be noted that, Figure 4 The motion trajectory shown is only one possible example. In actual scenarios, the trajectory can be set according to the requirements. This application embodiment does not limit this.

[0094] In this embodiment, the encoders of both the first and second steering wheels can be implemented using code disks, and the pose data collected by both are similar, both including the following data:

[0095] (1) The rotational speed at each detection moment, i.e. the real-time rotational speed of the steering wheel, is represented by the first rotational speed and the second rotational speed, respectively, in order to distinguish the position and pose data collected by the encoders of the first and second steering wheels.

[0096] (2) The rotation angle at each detection moment, that is, the real-time rotation angle of the steering wheel, that is, the angle rotated relative to the initial position of the code disk. Similarly, in order to distinguish the position and pose data collected by the encoders of the first steering wheel and the second steering wheel, the rotation angle of the first steering wheel is represented by the first rotation angle, and the rotation angle of the second steering wheel is represented by the second rotation angle.

[0097] In this embodiment of the application, when the guiding device is a laser, the third pose data it collects may include the following data:

[0098] (1) The deflection angle at each detection time, i.e. the real-time deflection angle of the target vehicle detected by the laser. The deflection angle can refer to the angle at which the target vehicle deflects relative to the reference angle in the laser coordinate system, or it can be the angle after transformation based on the reference angle.

[0099] (2) The location information at each detection time, i.e. the real-time location of the target vehicle detected by the laser, can be represented by coordinates in the laser coordinate system.

[0100] Step 302: Based on the correlation between the first pose data and the third pose data, determine the values ​​of each parameter to be calibrated for the first steering wheel and the external parameters of the guiding device relative to the center of the universal wheel. The center of the universal wheel is determined based on the positions of the first steering wheel and the second steering wheel in the target vehicle.

[0101] In this embodiment, since the guidance device and the first steering wheel are both installed on the target vehicle and do not usually move relative to the target vehicle, the pose data detected by both can reflect the state of the target vehicle. Therefore, there is a certain correlation between them. Thus, the calibration parameters related to the first steering wheel and the guidance device can be solved based on this correlation.

[0102] See Figure 3 As shown, step 302 may include the following two processes:

[0103] Step 3021: Solve for the zero deflection angle of the first steering wheel using rotational constraints.

[0104] In the embodiments of the present application, considering that the steering wheel and the laser are installed and then move following the target vehicle, the rotation angle determined based on the detection values of the two should be the same, and thus the zero offset angle of the first steering wheel can be determined by taking this as a constraint, i.e., taking the correlation between the first rotation angle corresponding to the first steering wheel and the third rotation angle corresponding to the guiding device as a constraint, and determining the zero offset angle of the first steering wheel based on the first rotation speed, the first rotation angle and the deflection angle.

[0105] Specifically, taking the laser as an example, the Iterated Closest Points (IPC) method can be used to determine the third rotation angle of the guiding device between every two adjacent time instants based on the deflection angle detected by the laser, and the zero offset angle can be determined based on the first rotation speed, the first rotation angle and the third rotation angle by taking the equality of the first rotation angle and the third rotation angle as a constraint. It should be noted that the deflection angle here is not a simple value, but a process state quantity, which represents the possibility of the actual deflection angle of the target vehicle.

[0106] In a possible implementation manner, the ICP solution can obtain the third rotation angle of the laser from t i to t i+1 , which can be expressed as Δθ l (ICP solution), where t i represents the i th time instant in the above driving trajectory; the first rotation angle of the first steering wheel A1 encoder from t i to t i+1 is Δθ o , and the rotation constraint in the two-dimensional plane can be degenerated as follows according to the rotation constraint:

[0107] Δθ l = Δθ o

[0108] which can be written in a matrix form as

[0109]

[0110] k1=r·cosθ offA1 / b

[0111] k2=r·sinθ offA1 / b

[0112] where n w represents the first rotation speed of the first steering wheel, θ w represents the first rotation angle of the first steering wheel, K can be obtained by solving the above linear equation set, and the zero offset of the steering wheel A1 is:

[0113]

[0114] Step 3022: solve the first steering wheel A1 distance from the universal wheel center W axis distance b, laser relative to the universal wheel W center of the external parameter (x o_l y o_l θ o_l ), the radius of the steering wheel A1 r A1 .

[0115] Similarly, after the steering wheel and the laser are installed, they both follow the target vehicle to move, so the displacement determined based on the detection values of the two should be the same, and thus the zero deflection angle of the first steering wheel can be determined based on the translational constraint, that is, the first steering wheel corresponding displacement vector and the guide device corresponding displacement vector are related as a constraint to determine the first steering wheel and the universal wheel center between the first axis distance, the radius and the external parameter of the guide device.

[0116] Specifically, taking the laser as an example, the Iterated Closest Points (IPC) method can also be used to determine the displacement vector between each two adjacent detection time points of the guide device based on the position information corresponding to each two adjacent detection time points, and then based on the correlation between the obtained displacement vector and the displacement vector corresponding to the first steering wheel, the first axis distance between the first steering wheel and the universal wheel center, and the external parameter of the guide device are determined; and based on the axis distance and the zero deflection angle, the radius of the first steering wheel is determined. It also needs to be explained that the position information here is not a simple value, but a process state quantity, which expresses the possibility of the actual position of the target vehicle.

[0117] Specifically, the ICP can be used to obtain the laser t i t i+1 translation vector:

[0118]

[0119] Since the position information of the laser is known, the translation vector is a known observation.

[0120] In addition, the t i t i+1 translation vector of the encoder of the first steering wheel A1 is:

[0121]

[0122] Since the radius of the first steering wheel is unknown, the translation vector is an unknown observation.

[0123] In one possible implementation, based on the hand-eye calibration algorithm AX=XB, the following results can be obtained:

[0124]

[0125]

[0126] wherein b is the wheelbase of the first steering wheel A1 from the center of the universal wheel W, (x o_l y o_l θ o_l ) is the extrinsic parameter of the laser relative to the center of the universal wheel W.

[0127] In another possible implementation, a least square equation based on the wheelbase and the extrinsic parameter can be constructed based on the displacement vector obtained by the laser, and the least square equation is solved to obtain the first wheelbase and the extrinsic parameter, with the constraint that the displacement vector obtained by the laser corresponds to the displacement vector of the first steering wheel.

[0128] Specifically, the translation constraint can be expressed as the following formula in a two-dimensional plane:

[0129]

[0130] wherein θ o corresponding to the first steering wheel, the translation vector of the encoder can be further expressed as:

[0131]

[0132] wherein [c x c y ] T The above translation constraint expression can be simplified as the following formula by integration:

[0133]

[0134] Based on the above formula, the following constrained least square equation is constructed:

[0135]

[0136]

[0137] M =∑Q k T Q k

[0138]

[0139]

[0140] Solving the least square equation, the following can be obtained:

[0141]

[0142]

[0143] Furthermore, the radius of the first steering wheel can be calculated using the following formula:

[0144]

[0145] Step 303: Based on the values ​​of each parameter to be calibrated of the first steering wheel and the correlation between the first pose data and the second pose data, determine the values ​​of each parameter to be calibrated of the second steering wheel.

[0146] In this embodiment, the relevant parameters of the first steering wheel can be obtained through the above steps, thereby revealing the mileage traveled by the first steering wheel. Since the second steering wheel moves with the target vehicle as well as the first steering wheel, their theoretical mileage is the same. Therefore, the relevant parameters of the second steering wheel can be determined based on the correlation between the two. Thus, based on the first rotational speed, the first turning angle, the radius of the first steering wheel, and the second turning angle, and constrained by the equality of the mileage traveled by the first and second steering wheels, the radius of the second steering wheel and the second wheelbase between the center of the second steering wheel and the omnidirectional wheel can be determined.

[0147] Specifically, for any two adjacent detection times in the preset trajectory, let t be an example. i To t i+1 For example, perform the following operations:

[0148] Based on the first rotational speed, first rotation angle, and radius of the first steering wheel at two adjacent detection moments, the displacement of the first steering wheel before the two adjacent detection moments is determined; based on the first wheelbase and the rotation angle of the first steering wheel at the previous moment in the two adjacent detection moments, the rotation radius of the first steering wheel at the two adjacent detection moments is determined; based on the ratio between the obtained displacement and the rotation radius, the displacement change rate of the first steering wheel is determined; based on the obtained displacement change rate, first wheelbase, and second rotation angle, an equation based on the second wheelbase and the radius of the second steering wheel is constructed; the equation is solved to obtain the second wheelbase and the radius of the second steering wheel.

[0149] See Figure 5 The diagram shown illustrates the principle for solving the relevant parameters of the second steering wheel. Here, Δl represents the encoder t of the first steering wheel A1. i To t i+1 The displacement, i.e., the arc distance N1N2, where N1 and N2 represent the positions of the first steering wheel at two different moments, i.e., t i To t i+1 The arc formed by N1 and N2 at the two corresponding moments is the trajectory of the steering wheel during that time period. Since the radius of the first steering wheel A1 has been solved above, Δl is a known observation. The angle of the first steering wheel A1 at that time is δ. The wheelbase b of the first steering wheel A1 from the center W of the omnidirectional wheel has been solved as a known quantity. Therefore, the following equation exists:

[0150]

[0151] Wherein, b / sin(δ) is the rotation radius of the first steering wheel A1.

[0152] In a possible implementation, the radius r of the second steering wheel A2 can be solved by using the least square method A2 and the axle distance a of the second steering wheel A2 from the universal wheel center W, then the following equation can exist:

[0153]

[0154] The left side of the above equation is the mileage of the first steering wheel A1, the right side of the equation is the mileage of the second steering wheel A2, θ f2 is the corresponding second rotation angle of the second steering wheel A2.

[0155] Substituting dθ into the above equation, the final equation can be obtained as follows:

[0156]

[0157]

[0158] Further, solving the above equation, a and R A2 can be obtained, and thus the calibration of all parameters of the target vehicle related to the double steering wheels is completed.

[0159] Next, with a specific embodiment, the calibration process of the embodiments of the present application will be introduced. Referring to Figure 6 , it is a flowchart of the calibration process.

[0160] Step 601: define the forward direction as the direction of the second steering wheel A2 when the steering wheel is reset, and reset the second steering wheel to zero.

[0161] Step 602: place the first steering wheel A1 to left 45°, zero and right 45° respectively, and send open loop speed to walk 3 paths.

[0162] Step 603: solve by using rotation constraint to obtain the zero offset angle of the first steering wheel A1.

[0163] Step 604: solve by using translation constraint to obtain the first axle distance of the first steering wheel A1 from the universal wheel center W, the radius of the first steering wheel A1 and the external parameter of the laser.

[0164] Step 605: solve by using the equation of equal displacement between the front and rear steering wheels to obtain the second axle distance of the second steering wheel A2 from the universal wheel center W and the radius of the second steering wheel A2.

[0165] In summary, the embodiment of the present application provides a joint calibration solving method for the encoder internal parameter and the laser external parameter of a double steering wheel model, which ingeniously converts the double steering wheel problem into a single steering wheel calibration, and solves the remaining quantities through the equation that the front and rear steering wheels walk the same distance. Specifically, the double steering wheels are made to walk along a specific 3-segment path, and the data of the laser and the encoder are collected. The radius r A1 of the front steering wheel A1, the zero offset θ offA1 of the front steering wheel, the axle distance b of the rear steering wheel relative to the center of the universal wheel, and the external parameter (x o_l y o_l θ o_l ) of the laser are calibrated by first converting the entire double steering wheel into a single steering wheel calibration. Then, the radius r A2 of the rear steering wheel A2 and the axle distance a of the rear steering wheel A2 relative to the center of the universal wheel W are calibrated by constructing the equation of the rear steering wheel with the calibrated quantities.

[0166] Please refer to Figure 7 Based on the same inventive concept, the embodiment of the present application also provides a double steering wheel parameter calibration device 70, which comprises:

[0167] A data acquisition unit 701 is configured to place a second steering wheel included in a target vehicle at a zero position, and acquire first pose data detected by an encoder of a first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle during driving of the target vehicle according to a preset trajectory; wherein the preset trajectory is a non-straight trajectory.

[0168] A first calculation unit 702 is configured to determine values of each to-be-calibrated parameter of the first steering wheel and an external parameter of the guiding device relative to a universal wheel center based on the correlation between the first pose data and the third pose data, wherein the universal wheel center is determined based on the positions of the first steering wheel and the second steering wheel in the target vehicle.

[0169] A second calculation unit 703 is configured to determine values of each to-be-calibrated parameter of the second steering wheel based on the values of each to-be-calibrated parameter of the first steering wheel and the correlation between the first pose data and the second pose data.

[0170] Optionally, the preset path comprises:

[0171] A first segment path, the first segment path is that the first steering wheel is adjusted by a first angle in a first direction and then travels for a first time length, and the first direction is any one of clockwise or counterclockwise.

[0172] A second segment path, the second segment path is that the first steering wheel is returned to zero from the first angle and then travels for a second time length.

[0173] a third segment path, the third segment path being a path of the first steering wheel after being adjusted by a first angle in a second direction for a first time length, the second direction being a reverse direction of the first direction.

[0174] Optionally, the first pose data comprises a first rotation speed and a first rotation angle of the first steering wheel at each detection time, and the third pose data comprises a deflection angle at each detection time and position information at each detection time.

[0175] The first computing unit 702 is specifically configured to:

[0176] determine a zero deflection angle of the first steering wheel based on the first rotation speed, the first rotation angle and the deflection angle, with a correlation between the first rotation angle corresponding to the first steering wheel and a third rotation angle corresponding to the guide device as a constraint.

[0177] determine a displacement vector between each two adjacent detection times of the guide device based on position information corresponding to each two adjacent detection times.

[0178] determine a first wheelbase between the first steering wheel and a center of the universal wheel and an extrinsic parameter of the guide device based on a correlation between each obtained displacement vector and a displacement vector corresponding to the first steering wheel.

[0179] determine a radius of the first steering wheel based on the wheelbase and the zero deflection angle.

[0180] Optionally, the first computing unit 702 is specifically configured to:

[0181] determine the third rotation angle of the guide device between each two adjacent times based on the deflection angle by using a least square iteration method.

[0182] determine the zero deflection angle based on the first rotation speed, the first rotation angle and the third rotation angle, with the first rotation angle being equal to the third rotation angle as a constraint.

[0183] Optionally, the first computing unit 702 is specifically configured to:

[0184] construct a least square equation based on the wheelbase and the extrinsic parameter based on the displacement vectors, with each displacement vector being equal to the displacement vector corresponding to the first steering wheel as a constraint.

[0185] solve the least square equation to obtain the first wheelbase and the extrinsic parameter.

[0186] Optionally, the first pose data comprises a second rotation angle of the second steering wheel at each detection time.

[0187] The second calculation unit 703 is specifically used for:

[0188] Based on the first rotational speed, the first turning angle, the radius of the first steering wheel, and the second turning angle, and with the constraint that the distance traveled by the first steering wheel is equal to the distance traveled by the second steering wheel, the radius of the second steering wheel and the second wheelbase between the second steering wheel and the center of the omnidirectional wheel are determined.

[0189] Optionally, the second computing unit 703 is specifically used for:

[0190] For any two adjacent detection times in the preset trajectory, perform the following operations:

[0191] Based on the first rotational speed, the first rotational angle, and the radius of the first steering wheel at two adjacent detection moments, the displacement of the first steering wheel before the two adjacent detection moments is determined;

[0192] Based on the first wheelbase and the rotation angle of the first steering wheel in the previous moment between the two adjacent detection moments, the rotation radius of the first steering wheel at the two adjacent detection moments is determined.

[0193] Based on the ratio between the obtained displacement and the rotation radius, the displacement change rate corresponding to the first steering wheel is determined;

[0194] Based on the obtained displacement change rate, the first wheelbase, and the second rotation angle, an equation is constructed based on the second wheelbase and the radius of the second steering wheel;

[0195] Solving the equation yields the second wheelbase and the radius of the second steering wheel.

[0196] The aforementioned device cleverly transforms the dual-steering wheel problem into a single-steering wheel calibration problem. After calculating some quantities, the remaining quantities are solved by applying an equation that the front and rear steering wheels travel equal distances. This device can be used to execute the methods shown in the various embodiments of this application. Therefore, the functions that each functional module of this device can achieve can be referred to the description of the foregoing embodiments, and will not be elaborated further.

[0197] Please see Figure 8 Based on the same technical concept, embodiments of this application also provide a computer device. In one embodiment, the computer device can be... Figure 1 The computer device, as mentioned in the corresponding embodiment section, is like... Figure 8 As shown, it includes a memory 801, a communication module 803, and one or more processors 802.

[0198] The memory 801 is configured to store computer programs executed by the processor 802. The memory 801 can mainly include a program storage area and a data storage area. The program storage area can store an operating system and programs required for running instant messaging functions, etc. The data storage area can store various instant messaging information and operation instruction sets, etc.

[0199] The memory 801 can be a volatile memory, for example, a random-access memory (RAM). The memory 801 can also be a non-volatile memory, for example, a read-only memory, a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD). Or the memory 801 can be any other medium capable of carrying or storing desired program codes in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. The memory 801 can be a combination of the above memories.

[0200] The processor 802 can include one or more central processing units (CPUs) or digital processing units, etc. The processor 802 is configured to invoke the computer programs stored in the memory 801 to implement the above double-rudder parameter calibration method.

[0201] The communication module 803 is configured to communicate with terminal devices and other servers.

[0202] The specific connection medium between the above memory 801, the communication module 803 and the processor 802 is not limited in the embodiments of the present application. In the embodiments of the present application, the memory 801 and the processor 802 are connected through a bus 804. The bus 804 is described by a thick line in the embodiments of the present application. The connection mode between other components is only schematically described and is not limited. The bus 804 can be divided into an address bus, a data bus, a control bus, etc. For the convenience of description, only one thick line is used to describe the bus 804 in the embodiments of the present application, but it is not described that there is only one bus or only one type of bus. Figure 8 Figure 8 Figure 8

[0203] The memory 801 stores computer storage media, and the computer storage media stores computer executable instructions. The computer executable instructions are used to implement the double-rudder parameter calibration method of the embodiments of the present application. The processor 802 is configured to execute the double-rudder parameter calibration method of each of the above embodiments.

[0204] In another embodiment, the computer device can also be other computer devices, such as​​​Figure 1 The terminal device mentioned in the corresponding embodiment part. In this embodiment, the structure of the computer device can be as shown in the figure, including: a communication component 910, a memory 920, a display unit 930, a camera 940, a sensor 950, an audio circuit 960, a Bluetooth module 970, a processor 980, and the like. Figure 9

[0205] The communication component 910 is used for communication with the server. In some embodiments, a wireless fidelity (WiFi) module can be included, which belongs to a short-range wireless transmission technology. The computer device can help users send and receive information through the WiFi module.

[0206] The memory 920 can be used to store software programs and data. The processor 980 executes various functions and data processing of the terminal device by running the software programs or data stored in the memory 920. The memory 920 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other volatile solid-state memory device. The memory 920 stores an operating system that enables the terminal device to operate. In this application, the memory 920 can store the operating system and various application programs, and can also store the code for executing the double-rudder parameter calibration method of the embodiment of the application.

[0207] The display unit 930 can also be used to display information input by the user or information provided to the user, as well as the graphical user interface (GUI) of various menus of the terminal device. Specifically, the display unit 930 can include a display screen 932 arranged on the front of the terminal device. The display screen 932 can be configured in the form of a liquid crystal display, a light-emitting diode, etc. The display unit 930 can be used to display various interfaces in the embodiment of the application, such as the control interface of the target vehicle, the double-rudder parameter calibration result page, and the real-time driving interface of the target vehicle.

[0208] The display unit 930 can also be used to receive input digital or character information, and generate signal input related to user settings and function control of the terminal device. Specifically, the display unit 930 can include a touch screen 931 arranged on the front of the terminal device, which can collect touch operations of the user thereon or therearound, such as clicking buttons, dragging scroll boxes, etc.

[0209] The touch screen 931 can be overlaid on the display screen 932, or the touch screen 931 and the display screen 932 can be integrated to realize the input and output functions of the terminal device. After integration, it can be simply referred to as a touch display screen. In this application, the display unit 930 can display application programs and corresponding operation steps. ​

[0210] The camera 940 can be used to capture still images, which a user can post comments on through an application. The camera 940 can be one or more. An object generates an optical image through a lens and projects the optical image onto a photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, which is then passed to the processor 980 to convert into a digital image signal.

[0211] The terminal device can also include at least one sensor 950, such as an acceleration sensor 951, a distance sensor 952, a fingerprint sensor 953, a temperature sensor 954. The terminal device can also be configured with a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, a light sensor, a motion sensor, and other sensors.

[0212] The audio circuit 960, the speaker 961, and the microphone 962 can provide an audio interface between the user and the terminal device. The audio circuit 960 can convert the received audio data into an electrical signal, which is transmitted to the speaker 961 and converted into a sound signal by the speaker 961. The terminal device can also be configured with a volume button for adjusting the volume of the sound signal. On the other hand, the microphone 962 converts the collected sound signal into an electrical signal, which is received by the audio circuit 960 and converted into audio data, which is then output to the communication component 910 for transmission to, for example, another terminal device, or to the memory 920 for further processing.

[0213] The Bluetooth module 970 is used to interact with other Bluetooth devices with Bluetooth modules through Bluetooth protocols. For example, the terminal device can establish a Bluetooth connection with a wearable computer device (e.g., a smart watch) that also has a Bluetooth module through the Bluetooth module 970, and thus interact with data.

[0214] The processor 980 is a control center of the terminal device, connects all parts of the terminal through various interfaces and lines, and performs various functions of the terminal device and processes data by running or executing software programs stored in the memory 920 and calling data stored in the memory 920. In some embodiments, the processor 980 can include one or more processing units; the processor 980 can also integrate an application processor and a baseband processor, wherein the application processor mainly processes operating systems, user interfaces, and application programs, and the baseband processor mainly processes wireless communication. It can be understood that the above-mentioned baseband processor can also not be integrated into the processor 980. In the present application, the processor 980 can run an operating system, an application program, a user interface display and a touch response, and a double rudder parameter calibration method of the embodiments of the present application. In addition, the processor 980 is coupled with the display unit 930.

[0215] In some possible implementation manners, various aspects of the double rudder parameter calibration method provided by the present application can also be implemented in the form of a program product, which includes program codes for causing a computer device to execute the steps of the double rudder parameter calibration method according to various exemplary embodiments of the present application described above in the specification when the program product is run on the computer device, for example, the computer device can execute the steps of the embodiments.

[0216] The program product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium may, for example, be but is not limited to an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination of the above. More specific examples (non-exhaustive list) of readable storage media include an electrical connection having one or more wires, a portable disc, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0217] The program product of the embodiments of the present application can adopt a portable compact disc read-only memory (CD-ROM) and include program codes, and can be run on a computing device. However, the program product of the present application is not limited to this, and in the present application, the readable storage medium can be any tangible medium containing or storing a program, which can be used by or in combination with a command execution system, device or apparatus.

[0218] A readable signal medium can be any medium that can be read by a machine (e.g., a computer) and can contain any combination of instructions and data that can be used to program a processing device, such as a general-purpose computer. The readable signal medium can also be any medium that can be used to make the program elements available for reading by a machine.

[0219] The program code embodied on the readable medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0220] Program code embodied on a readable medium can be executed by one or more processing devices utilizing any suitable operating system. As will be apparent to those of ordinary skill in the art, other program code, which is indicative of a set of instructions that can be executed by a processor or computing device, can also be used. A "processor" includes any hardware system, apparatus, or device that processes data, such as a computer or system on a chip. A processor can include any of both processors and multi-processors and both can be coupled to memory that stores program code, data, or both for execution by the processor. A processor can include any suitable processor, such as a conventional processor, a microprocessor, a microcontroller, a programmable logic device, a dedicated controller, or any other processing device or system.

[0221] It should be noted that, although the foregoing detailed description has set forth several embodiments of the devices and / or methods, no limitations are intended to the details of those embodiments disclosed herein, but rather such details are contemplated to be among the specific embodiments. It is therefore contemplated that the features, functions, and / or functions described herein can be implemented in one or more embodiments. It is also contemplated that the features, functions, and / or functions described herein can be implemented in a combination of two or more specific embodiments. It is further contemplated that features, functions, and / or functions described herein can be implemented in an installation environment, such as a computer system or the like, which has multiple instances of a functional design.

[0222] Further, although processes of the present application have been described in a certain order, this is not meant to be a limitation on the order of the processes for carrying out the methodologies described herein, nor is it required that all described processes be carried out, but rather the processes can be carried out in any order, or some of the processes can be omitted, combined, or divided into further processes.

[0223] Those skilled in the art will appreciate that embodiments of the present application can be devised for a method, a system, or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer readable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code thereon for use by or in connection with an instruction execution system. For the purposes of this description, a computer usable or computer readable storage medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

[0224] Although preferred embodiments of the application have been described herein, those skilled in the art will appreciate that other changes and modifications can be made to the embodiments described without departing from the spirit and scope of the application. It is therefore intended that the appended claims encompass all such changes and modifications as fall within the scope of the application.

[0225] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for calibrating parameters of a dual rudder wheel, characterized in that, The method comprises: Placing a second steering wheel included in a target vehicle at zero position, and obtaining first pose data detected by an encoder of the first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle during driving of the target vehicle according to a preset track; wherein the preset track is a non-straight track; Based on the first pose data and the third pose data, determining each to-be-calibrated parameter value of the first steering wheel and an external parameter of the guiding device relative to a universal wheel center, the universal wheel center being determined based on positions of the first steering wheel and the second steering wheel in the target vehicle, as a constraint between a first rotation angle corresponding to the first steering wheel and a third rotation angle corresponding to the guiding device, and as a constraint between a displacement vector between each two adjacent detection time instants detected by the guiding device and a displacement vector corresponding to the first steering wheel; Based on each to-be-calibrated parameter value of the first steering wheel, and the first pose data and the second pose data, determining each to-be-calibrated parameter value of the second steering wheel as a constraint that a mileage walked by the first steering wheel is equal to a mileage walked by the second steering wheel.

2. The method of claim 1, wherein, The preset path comprises: A first path segment, the first path segment being a first time length after the first steering wheel is adjusted by a first angle in a first direction, the first direction being any one of clockwise or counterclockwise; A second path segment, the second path segment being a second time length after the first steering wheel is returned to zero from the first angle; A third path segment, the third path segment being the first time length after the first steering wheel is adjusted by the first angle in a second direction, the second direction being an opposite direction of the first direction.

3. The method of claim 1, wherein, The first pose data comprises a first rotation speed and a first rotation angle of the first steering wheel at each detection time instant, and the third pose data comprises a deflection angle at each detection time instant and position information at each detection time instant; Then, based on the first pose data and the third pose data, determining the parameters of the first steering wheel and the external parameter of the guiding device comprises: Determining a zero deflection angle of the first steering wheel based on the first rotation speed, the first rotation angle, and the deflection angle as a constraint between a first rotation angle corresponding to the first steering wheel and a third rotation angle corresponding to the guiding device; Determining a displacement vector between each two adjacent detection time instants detected by the guiding device based on position information corresponding to each two adjacent detection time instants; Determining a first wheelbase between the first steering wheel and the universal wheel center and the external parameter of the guiding device based on a correlation between each obtained displacement vector and a displacement vector corresponding to the first steering wheel as a constraint; Determining a radius of the first steering wheel based on the wheelbase and the zero deflection angle.

4. The method of claim 3, wherein, Determining a zero deflection angle of the first steering wheel based on the first rotation speed, the first rotation angle, and the deflection angle as a constraint between a first rotation angle corresponding to the first steering wheel and a third rotation angle corresponding to the guiding device comprises: determine, based on the deflection angle, a third rotation angle of the guiding device between each two adjacent time instants using a least square method; determine the zero deflection angle based on the first rotation speed, the first rotation angle and the third rotation angle, with the constraint that the first rotation angle is equal to the third rotation angle.

5. The method of claim 3, wherein, determine the first wheelbase between the first steering wheel and the center of the universal wheel and the extrinsic parameters of the guiding device based on the correlation between each displacement vector and the displacement vector corresponding to the first steering wheel, and the first wheelbase and the extrinsic parameters including: construct a least square equation based on the wheelbase and the extrinsic parameters with the constraint that each displacement vector is equal to the displacement vector corresponding to the first steering wheel; solve the least square equation to obtain the first wheelbase and the extrinsic parameters.

6. The method of any one of claims 3-5, wherein, The second pose data includes a second rotation angle of the second steering wheel at each detection time instant; determine the values of each to-be-calibrated parameter of the second steering wheel based on the values of each to-be-calibrated parameter of the first steering wheel, the first pose data and the second pose data, and with the constraint that the mileage of the first steering wheel is equal to the mileage of the second steering wheel. determine the radius of the second steering wheel and the second wheelbase between the second steering wheel and the center of the universal wheel based on the first rotation speed, the first rotation angle and the radius of the first steering wheel, and the second rotation angle, with the constraint that the mileage of the first steering wheel is equal to the mileage of the second steering wheel.

7. The method of any one of claims 3-5, wherein, determine the radius of the second steering wheel and the second wheelbase between the second steering wheel and the center of the universal wheel based on the first rotation speed, the first rotation angle and the radius of the first steering wheel, and the second rotation angle, with the constraint that the mileage of the first steering wheel is equal to the mileage of the second steering wheel. For any two adjacent detection time instants in the preset trajectory, the following operations are performed: determine the displacement of the first steering wheel before the two adjacent detection time instants based on the first rotation speed, the first rotation angle and the radius of the first steering wheel at the two adjacent detection time instants; determine the rotation radius of the first steering wheel at the two adjacent detection time instants based on the first wheelbase and the rotation angle of the first steering wheel at the previous time instant among the two adjacent detection time instants; determine the displacement rate of the first steering wheel corresponding to the displacement based on the ratio between the obtained displacement and the rotation radius; construct an equation based on the second wheelbase and the radius of the second steering wheel based on the obtained displacement rate, the first wheelbase and the second rotation angle; solve the equation to obtain the second wheelbase and the radius of the second steering wheel.

8. A dual rudder wheel parameter calibration device, characterized in that, The device comprises: a data acquisition unit configured to place a second steering wheel included in a target vehicle at a zero position, and acquire first pose data detected by an encoder of a first steering wheel, second pose data detected by an encoder of the second steering wheel, and third pose data detected by a guiding device on the target vehicle during driving of the target vehicle according to a preset trajectory; wherein the preset trajectory is a non-straight trajectory. The first computing unit is configured to determine, based on the first pose data and the third pose data, the to-be-calibrated parameter values of the first steering wheel and the external parameter of the guide device relative to the universal wheel center, as a constraint between a first rotation angle corresponding to the first steering wheel and a third rotation angle corresponding to the guide device, and as a constraint between a displacement vector between every two adjacent detection time instants detected by the guide device and a displacement vector corresponding to the first steering wheel, the universal wheel center being determined based on positions of the first steering wheel and the second steering wheel in the target vehicle; The second computing unit is configured to determine, based on the to-be-calibrated parameter values of the first steering wheel and the first pose data and the second pose data, the to-be-calibrated parameter values of the second steering wheel, as a constraint that a mileage of the first steering wheel is equal to a mileage of the second steering wheel. 9.A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: The processor implements steps of the method in any one of claims 1 to 7 when executing the computer program. 10.A computer storage medium having computer program instructions stored thereon, wherein: The computer program instructions are executed by a processor to implement steps of the method in any one of claims 1 to 7. 11.A computer program product, comprising computer program instructions, wherein: The computer program instructions are executed by a processor to implement steps of the method in any one of claims 1 to 7.

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