Target locking method, device, equipment and readable storage medium

Abstract

The present application discloses a target locking method, apparatus, device, and readable storage medium, the method comprising the steps of: obtaining the current speed and yaw rate of a vehicle; establishing a non-inertial reference system with the vehicle as the coordinate origin; obtaining a reference target located in front of the vehicle when the speed is within a preset vehicle speed range, and obtaining a first position parameter of the reference target in the non-inertial reference system; calculating a second position parameter of the reference target in the non-inertial reference system based on the non-inertial reference system, the first position parameter, and the yaw rate, so as to determine the position of the reference target based on the second position parameter. The present application realizes the precise calculation of the second position parameter of the reference target after relative motion by establishing a dynamic non-inertial reference system and combining the yaw rate, vehicle speed, and the first position parameter of the reference target.

Description

Technical Field

[0001] The present application relates to the field of autonomous driving, and in particular to a target locking method, device, equipment and readable storage medium. Background Art

[0002] With the continuous development of vehicle autonomous driving technology, some vehicles now have autonomous driving functions. The autonomous driving function relies on data fusion from multiple sensors on the vehicle to predict obstacles in front of the vehicle, driving routes, etc.

[0003] However, when the vehicle enters a curve, the vehicle's forward direction keeps changing, making it impossible to accurately calculate the relative position of the vehicle and the reference point in front of the vehicle, and thus impossible to lock the reference point to calculate the driving trajectory. Summary of the Invention

[0004] In view of this, the present application provides a target locking method, apparatus, device and readable storage medium, aiming to improve the accuracy of calculating the position parameters of the target in front of the vehicle.

[0005] To achieve the above objectives, the present application provides a target locking method, which includes the following steps:

[0006] Obtaining the current speed of the vehicle and the yaw rate of the vehicle;

[0007] A dynamically changing non-inertial reference system is established with the vehicle as the coordinate origin;

[0008] When the speed is within a preset vehicle speed range, obtaining a reference target located in front of the vehicle, and obtaining a first position parameter of the reference target in the non-inertial reference system;

[0009] A second position parameter of the reference target after relative motion is obtained by calculation based on the non-inertial reference system, the first position parameter, and the yaw angular velocity.

[0010] Exemplarily, the calculating, based on the non-inertial reference system, the first position parameter, and the yaw angular velocity, to obtain the second position parameter of the reference target after the relative motion occurs includes:

[0011] Determining an inertial reference frame in which the reference target is located based on the first position parameter;

[0012] calculating an absolute velocity of the vehicle relative to the inertial reference system based on the first position parameter;

[0013] calculating a velocity of the reference target relative to a non-inertial reference frame based on the first position parameter and the yaw angular velocity;

[0014] Based on the absolute speed and the involved speed, a second position parameter of the reference target after the relative motion is obtained by calculation.

[0015] Exemplarily, after determining the inertial reference frame where the reference target is located based on the first position parameter, the method further includes:

[0016] The vehicle is used as a moving mass point for calculating velocity and acceleration; the moving mass point is used to calculate the driving conditions of the vehicle in the non-inertial reference system and the inertial reference system;

[0017] The path from the vehicle to the reference target is used as the vector path of the moving particle; wherein the vector path is used to calculate the motion of the moving particle in different coordinate systems.

[0018] Exemplarily, calculating the absolute speed of the vehicle relative to the inertial reference system based on the first position parameter includes:

[0019] In the inertial reference system, calculating the derivative of the vector path with respect to a preset time to obtain an absolute velocity;

[0020] After calculating the derivative of the vector path with respect to a preset time in the inertial reference frame to obtain the absolute velocity, the method further includes:

[0021] The derivative of the absolute speed with respect to the preset time is calculated to obtain an absolute acceleration; the absolute acceleration is used to calculate the relative motion of the vehicle in the inertial reference frame.

[0022] Exemplarily, the calculating, based on the first position parameter and the yaw angular velocity, the drag velocity of the reference target relative to the non-inertial reference frame includes:

[0023] In the non-inertial reference frame, calculating the derivative of the vector path with respect to the preset time to obtain a relative velocity;

[0024] The difference between the absolute speed and the relative speed is calculated to obtain the involved speed.

[0025] Exemplarily, after calculating the velocity of the reference target relative to the non-inertial reference frame based on the first position parameter and the yaw angular velocity, the method further includes:

[0026] respectively calculating derivatives of the relative speed and the involved speed with respect to the preset time to obtain relative acceleration and involved acceleration;

[0027] The difference between the absolute acceleration, the relative acceleration and the involved acceleration is calculated to obtain the Coriolis acceleration; the Coriolis acceleration is used to calculate the dynamic change between the non-inertial reference system and the inertial reference system.

[0028] Exemplarily, after calculating the second position parameter of the reference target after the relative motion based on the absolute speed and the involved speed, the method further includes:

[0029] Calculating a plurality of second position parameters of the reference target in the non-inertial reference frame based on a preset detection interval duration;

[0030] Fitting a motion trajectory curve of the reference target in the non-inertial reference frame based on the multiple second position parameters;

[0031] The motion trajectory curve is output to a vehicle-mounted sensor so that the sensor can predict the position of the reference target at the next moment.

[0032] Exemplarily, to achieve the above-mentioned purpose, the present application further provides a target locking device, the device comprising:

[0033] A first acquisition module is used to acquire the current speed of the vehicle and the yaw rate of the vehicle;

[0034] Establishment module: used for establishing a dynamically changing non-inertial reference system with the vehicle as the coordinate origin;

[0035] A second acquisition module is configured to acquire a reference target located in front of the vehicle and acquire a first position parameter of the reference target in the non-inertial reference system when the speed is within a preset vehicle speed range;

[0036] A calculation module is configured to calculate a second position parameter of the reference target after relative motion based on the non-inertial reference system, the first position parameter, and the yaw angular velocity.

[0037] Exemplarily, to achieve the above-mentioned purpose, the present application also provides a target locking device, which includes: a memory, a processor, and a target motion compensation calculation program stored on the memory and executable on the processor, wherein the target motion compensation calculation program is configured to implement the steps of the target locking method described above.

[0038] Exemplarily, to achieve the above-mentioned purpose, the present application also provides a computer-readable storage medium, on which a target motion compensation calculation program is stored. When the target motion compensation calculation program is executed by a processor, the steps of the target locking method described above are implemented.

[0039] Compared with the prior art, where the vehicle's direction of travel keeps changing, resulting in the inability to accurately calculate the relative position of the vehicle and the reference point in front of the vehicle, and thus the inability to lock the reference point to calculate the driving trajectory, the present application realizes real-time monitoring of the vehicle's current speed and yaw rate, and at the same time establishes a non-inertial reference system with the vehicle as the coordinate origin that changes dynamically as the vehicle travels. When the vehicle's current speed is within a preset speed range, a reference target serving as a detection reference and a first position parameter of the reference target are obtained from the front of the vehicle. As the vehicle travels in a curve, the non-inertial reference system, the first position parameter and the yaw rate are combined to calculate the dynamic changes in the vehicle's driving process, determine the second position parameter of the reference target, and thereby determine the change in the position of the reference target during the vehicle's driving process, thereby accurately locking the reference target, and achieving the effect of accurately calculating the vehicle's current driving trajectory. That is, a dynamic non-inertial reference system is established with the vehicle as the coordinate origin, and the second position parameter of the reference target in the non-inertial reference system is accurately calculated by combining the vehicle's current speed, yaw angular velocity and first position parameter, so as to achieve the effect of accurately locking the reference target when the vehicle enters a curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of the first embodiment of the target locking method of the present application;

[0041] Figure 2 This is a schematic diagram of the rotation relationship of the non-inertial reference frame relative to the inertial reference frame in the target locking method of this application;

[0042] Figure 3 This is a flow chart of the second embodiment of the target locking method of the present application;

[0043] Figure 4 This is a flowchart of the third embodiment of the target locking method of the present application;

[0044] Figure 5 This is a flowchart of the fourth embodiment of the target locking method of the present application;

[0045] Figure 6 It is a structural diagram of the hardware operating environment involved in the embodiment of the present application.

[0046] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0047] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0048] This application provides a target locking method, referring to Figure 1 , Figure 1 This is a flow chart of the first embodiment of the target locking method of the present application.

[0049] The embodiments of the present application provide an embodiment of a target locking method. It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than here. For ease of description, the following description of the steps of the target locking method is omitted. The target locking method includes:

[0050] Step S110: obtaining the current speed of the vehicle and obtaining the yaw angular velocity of the vehicle;

[0051] The vehicle's autonomous driving mode usually uses on-board sensors to judge the vehicle's surrounding conditions. For example, for static or dynamic objects in front of the vehicle, it measures the relative position between the vehicle and the object, thereby achieving functions such as avoiding obstacles, avoiding other vehicles, driving in a standardized lane, and responding to emergency braking situations that occur during driving.

[0052] When a vehicle enters a curve, its direction of travel will change according to its current speed and the yaw rate of the vehicle body. At this time, before the vehicle enters the curve, the vehicle's on-board sensors will select an object to be used as a reference target. During the vehicle's travel, the object will produce a large relative position change relative to the vehicle. For example, when the vehicle turns, the vehicle's speed changes in multiple directions based on the object as a reference, and the direction of the vehicle body also rotates.

[0053] The yaw rate is the vehicle's deflection about its vertical axis, representing its stability. The vertical axis is perpendicular to the ground. The yaw rate is used to assess the vehicle's current stability. When the yaw rate exceeds a threshold, the vehicle is considered unstable and presents a driving risk.

[0054] By detecting the vehicle's current speed and yaw rate, the vehicle's current state in the curve is determined. The vehicle's trajectory in the curve is calculated based on the vehicle's current speed.

[0055] During vehicle driving, for example, when the vehicle is driving in a straight line or entering a curve, the yaw rate of the vehicle tends to be almost zero in a very short period of time. Therefore, the yaw rate is usually calculated as a constant value.

[0056] The yaw angular velocity can be directly obtained through the inertial sensor carried by the vehicle.

[0057] Step S120: establishing a dynamically changing non-inertial reference system with the vehicle as the coordinate origin;

[0058] When a vehicle is moving, its position is constantly changing. A coordinate system is established with the vehicle as the coordinate origin. This coordinate system undergoes corresponding dynamic changes as the position of the vehicle changes. Therefore, the coordinate system established with the position of the moving vehicle is a non-inertial reference system.

[0059] Compared with establishing an inertial reference frame, the non-inertial reference frame established based on the vehicle's own position directly reflects the dynamic changes of the vehicle during driving.

[0060] For example, when a vehicle is traveling in a curve, two changes occur in the state of the vehicle from the entrance to the curve exit. One is the change in the vehicle's driving direction, and the other is the yaw angular velocity generated by the vehicle itself, which causes the vehicle to rotate.

[0061] Reference Figure 2 , Figure 2 Schematic diagram of the rotation relationship of a fixed point in a non-inertial reference frame relative to an inertial reference frame.

[0062] Among them, with point 0 as the coordinate origin, an inertial reference system consisting of the X0 axis, Y0 axis and Z0 axis is established. This inertial reference system is used to express the effect of the inertial reference system when the vehicle does not generate a yaw angular velocity. Among them, with point 0 as the coordinate origin, a non-inertial reference system consisting of the X axis, Y axis and Z axis is established. When the vehicle does not generate a yaw angular velocity, the non-inertial reference system coincides with the inertial reference system. However, when the non-inertial reference system is affected by the yaw angular velocity of the vehicle, the non-inertial reference system will deflect around the same coordinate origin as the inertial reference system. That is, when the vehicle enters a curve, the vehicle will generate a corresponding yaw angular velocity, and the vehicle's non-inertial reference system will produce relative rotation with respect to the inertial reference system.

[0063] When rotation occurs between a non-inertial reference frame and an inertial reference frame, corresponding parameters such as the involved velocity and involved acceleration are generated. If the inertial reference frame is directly established with the vehicle as the coordinate origin, while ignoring the yaw angular velocity generated by the vehicle and the involved velocity and involved acceleration between the non-inertial reference frame and the inertial reference frame, the calculation accuracy will be reduced. Therefore, a dynamically changing non-inertial reference frame is established with the vehicle as the coordinate origin.

[0064] Among them, r is the vector path starting from the coordinate origin.

[0065] Step S130: When the speed is within a preset vehicle speed range, obtaining a reference target located in front of the vehicle, and obtaining a first position parameter of the reference target in the non-inertial reference system;

[0066] Before obtaining the benchmark target in front of the vehicle as a measurement basis, the vehicle's current speed will be detected and judged to determine whether the current speed meets the calculation benchmark target. If the current speed does not fall within the preset speed range, the benchmark target in front of the vehicle will not be selected and calculated.

[0067] The preset vehicle speed range is used as a standard range value for judging the vehicle speed, so as to exclude the vehicle speed being too low or too high.

[0068] For example, when the current speed of the vehicle is too high or too low, it will affect the vehicle position measurement.

[0069] When the vehicle's current speed is too high, the onboard speed sensor may fail, and the vehicle may be in a faulty state, which can lead to poor prediction capabilities of the vehicle dynamics model, inaccurate predictions of the forward target, and data association errors. Therefore, when the vehicle's current speed is too high, it is not appropriate to use onboard sensors to measure the reference target.

[0070] Among them, when the current speed of the vehicle is too low, the vehicle is driving slowly. At this time, when the on-board sensor measures the reference target in front of the vehicle, the error generated is small. The reference target is directly monitored by the video monitoring sensor, and the target will not be unable to be locked due to the excessive speed of the vehicle. Therefore, when the current speed is too low, there is no need to use the method of establishing a non-inertial reference system to measure the reference target.

[0071] At the same time, there is a malfunction in the speed measuring instrument such as the sensor or monitor that monitors the current speed of the vehicle, and the current speed detected is a negative number or an excessively large value. Such values are not within the preset speed range, so as to avoid the problem that the calculation result deviates too much from the normal value due to damage to the speed measuring instrument.

[0072] When the vehicle speed meets the judgment condition, a reference target is obtained, where the reference target is a static target in front of the vehicle. The geodetic coordinate system is a static coordinate system with the ground as the coordinate origin.

[0073] After obtaining the reference target, the reference target is used to measure changes in the vehicle's driving path. The vehicle must remain locked to the reference target. However, the vehicle speed, yaw angular velocity, etc. generated when entering a curve hinder the vehicle from locking onto the reference target. Therefore, after obtaining the reference target, the first position parameter of the reference target in the non-inertial coordinate system is obtained. The first position parameter is used for subsequent calculation of the motion state of the reference target in the non-inertial coordinate system.

[0074] For example, depending on the type of target selected, different measurement results will be produced for static targets and dynamic targets. The measurement content is to measure the first position parameters of the reference target in the non-inertial coordinate system.

[0075] When measuring a static target, the velocity and acceleration of the static target relative to the vehicle in a non-inertial reference frame are calculated. The static target remains stationary in the static coordinate system, meaning it is in relative motion with the vehicle.

[0076] Among them, when measuring dynamic targets, the relative motion between the dynamic target and the vehicle is taken into account. Combined with the relative motion and the change in the motion parameters of the vehicle relative to the static coordinate system in the non-inertial reference system, the current speed and driving trend of the dynamic target are calculated. This part of the parameters is used as compensation parameters and introduced into the current motion parameter calculation of the vehicle.

[0077] During vehicle travel, a static target is typically selected to calculate the vehicle's historical posture or the relative motion of the static target. This reduces the complexity of calculations performed by onboard sensors and systems. Therefore, the following descriptions of reference targets use static targets as examples.

[0078] Exemplarily, a static target is a static object located in front of the vehicle during driving. The static target may be a road sign, roadblock, roadside fence, etc. located in front of the vehicle. The static target in this embodiment is mainly the historical position of the front vehicle. The static is the virtual position of the front target. The virtual position is the static position point of the front target vehicle, that is, the new position of the front target in the non-inertial coordinate system when the vehicle and the front target produce relative motion.

[0079] After determining a reference target as a measurement reference, the coordinate parameters of the reference target in the non-inertial reference system are determined according to the non-inertial reference system of the vehicle.

[0080] When the vehicle is driving, the target in front will produce speed changes in the X-axis direction and the Y-axis direction of the non-inertial reference system. Therefore, the coordinate parameter includes the X-axis coordinate parameter and the Y-axis coordinate parameter, which is the first position parameter.

[0081] Step S140: Calculating a second position parameter of the reference target after relative motion based on the non-inertial reference system, the first position parameter, and the yaw angular velocity.

[0082] When the vehicle is moving toward the reference target, the reference target is stationary relative to the ground, that is, the reference target is stationary relative to the moving vehicle.

[0083] If the vehicle is in a stationary state, the corresponding reference target is in a relatively moving state.

[0084] Based on the non-inertial reference system, the first position parameter, and the yaw angular velocity, with the vehicle as the static coordinate origin, after detecting that the reference target generates a motion trajectory in the non-inertial reference system, the position parameter change of the reference target in the non-inertial reference system is further detected, thereby calculating the dynamic change of the reference target in the non-inertial reference system within a preset time length, that is, determining the second position parameter of the reference target in the non-inertial reference system, and thus locking the position of the reference target.

[0085] Among them, the preset time length is usually an extremely short time, for example, 40 milliseconds or 50 milliseconds. When the vehicle is moving straight forward or turning forward normally, the vehicle will produce subtle changes in speed and direction in a very short time. At the same time, the preset time length is used as the detection time length unit to calculate the state changes of the vehicle during driving. With the measurement standard at the millisecond level, the yaw angular velocity of the vehicle is almost a constant value.

[0086] Compared with the prior art, where the vehicle's direction of travel keeps changing, resulting in the inability to accurately calculate the relative position of the vehicle and the reference point in front of the vehicle, and thus the inability to lock the reference point to calculate the driving trajectory, the present application realizes real-time monitoring of the vehicle's current speed and yaw rate, and at the same time establishes a non-inertial reference system with the vehicle as the coordinate origin that changes dynamically as the vehicle travels. When the vehicle's current speed is within a preset speed range, a reference target serving as a detection reference and a first position parameter of the reference target are obtained from the front of the vehicle. As the vehicle travels in a curve, the non-inertial reference system, the first position parameter and the yaw rate are combined to calculate the dynamic changes in the vehicle's driving process, determine the second position parameter of the reference target, and thereby determine the change in the position of the reference target during the vehicle's driving process, thereby accurately locking the reference target, and achieving the effect of accurately calculating the vehicle's current driving trajectory. That is, a dynamic non-inertial reference system is established with the vehicle as the coordinate origin, and the second position parameter of the reference target in the non-inertial reference system is accurately calculated by combining the vehicle's current speed, yaw angular velocity and first position parameter, so as to achieve the effect of accurately locking the reference target when the vehicle enters a curve.

[0087] For example, refer to Figure 3 , Figure 3 : is a flow chart of the second embodiment of the target locking method of the present application. Based on the first embodiment of the target locking method of the present application, the second embodiment is proposed. The method further includes:

[0088] Step S210: determining the inertial reference frame where the reference target is located based on the first position parameter;

[0089] The first position parameter is the initial coordinate parameter of the reference target in the non-inertial reference frame, that is, the initial coordinate parameter when the vehicle does not generate relative motion after the non-inertial reference frame is currently established. At this time, the inertial reference frame where the reference target is located is determined by the first position parameter.

[0090] The inertial reference frame of the reference target is usually a geodetic coordinate system based on the earth, that is, a static coordinate system. However, when a vehicle enters a curve, it will generate a yaw angular velocity, causing the non-inertial reference frame established with the vehicle as the coordinate origin to produce a corresponding rotation. Therefore, when determining the inertial reference frame of the reference target, the specific parameters of the first position parameter are used to determine the non-inertial reference frame in which the current vehicle does not rotate about the coordinate origin. The inertial reference frame of the reference target is determined based on the directions of the horizontal and vertical axes of the non-inertial reference frame to facilitate the subsequent calculation of the deflection effect of the non-inertial reference frame.

[0091] Exemplarily, after determining the inertial reference frame where the reference target is located based on the first position parameter, the method further includes:

[0092] Step a: using the vehicle as a moving mass point for calculating velocity and acceleration; the moving mass point is used to calculate the driving conditions of the vehicle in the non-inertial reference frame and the inertial reference frame;

[0093] A non-inertial reference system is established, and the first position parameter of the reference target is obtained. According to the driving conditions of the vehicle, the relative motion between the vehicle and the reference target is calculated, thereby calculating the motion of the reference target in the non-inertial reference system.

[0094] Among them, when calculating the motion situation, it is usually necessary to calculate parameters such as the velocity and acceleration of the reference target in the non-inertial reference frame.

[0095] For example, under the conditions of different coordinate systems, the calculated parameters of velocity and acceleration are different. For example, in a non-inertial reference system, it is necessary to consider the involved velocity and involved acceleration generated during the movement when the non-inertial reference system is deflected relative to the inertial coordinate system. For another example, in an inertial reference system, it is not necessary to consider the involved velocity and involved acceleration.

[0096] Among them, selecting different moving objects in different coordinate systems will produce different calculation results. For example, if a vehicle is directly selected as a moving particle in an inertial reference system, the calculation process cannot consider the problem of rotation in the non-inertial reference system. For example, in a non-inertial reference system, the motion trajectory of the reference target is calculated, that is, the involved velocity and involved acceleration in the non-inertial reference system are calculated and considered accordingly.

[0097] The vehicle is selected as the moving mass point. On the one hand, in addition to the relative motion with the reference target, the vehicle itself also generates related yaw angular velocity. Taking the vehicle as the moving mass point, it is convenient to calculate the involved velocity and involved acceleration of the non-inertial reference frame where the vehicle is located. On the other hand, the relative motion between the vehicle and the reference target can be reflected through the vehicle's driving process.

[0098] Step b: Using the path from the vehicle to the reference target as the vector path of the moving particle; wherein the vector path is used to calculate the motion of the moving particle in different coordinate systems.

[0099] The reference target is usually the target in front of the vehicle that serves as the measurement standard. The vehicle's driving direction is always towards the reference target. Therefore, the position of the reference target pointed from the vehicle's position is the vehicle's current driving direction. The path between the two is the path the vehicle will travel, that is, the vector path. The direction of the vector path is the direction the vehicle will travel.

[0100] The motion of the vehicle in the inertial coordinate system and the non-inertial coordinate system is calculated based on the vector path, that is, the vehicle's speed, acceleration and other parameters are calculated based on the parameters of the vector path.

[0101] Step S220: Calculating the absolute speed of the vehicle relative to the inertial reference system based on the first position parameter;

[0102] In physics, the speed of a particle relative to the ground or a stationary object on the ground, that is, the speed of a particle relative to a static coordinate system or an inertial reference system, is generally called absolute speed. The speed of a particle relative to a moving reference system is called relative speed. The reference system of this movement is a non-inertial reference system, that is, the speed of a particle relative to a non-inertial reference system is the relative speed.

[0103] The speed of the non-inertial reference frame relative to the ground is called the entrainment velocity, that is, the yaw angular velocity generated by the vehicle is the speed generated when the non-inertial reference frame established with the vehicle as the coordinate origin rotates relative to the inertial reference frame.

[0104] Absolute speed = implicated speed + relative speed. Since speed is a vector, the above calculations between absolute speed, relative speed, and implicated speed apply the vector synthesis method.

[0105] The yaw rate is also the velocity relative to the inertial reference frame. Therefore, by considering the yaw rate and combining it with the vehicle's current normal forward speed, the absolute velocity of the vehicle relative to the inertial reference frame can be calculated.

[0106] Exemplarily, calculating the absolute speed of the vehicle relative to the inertial reference system based on the first position parameter includes:

[0107] Step c: calculating the derivative of the vector path with respect to a preset time in the inertial reference frame to obtain an absolute velocity;

[0108] The preset time is the length of the current vehicle movement time. For example, when calculating the absolute speed, the absolute speed within the preset time is considered, that is, the preset time is the measurement standard for calculating the absolute speed.

[0109] The vector path is calculated as:

[0110] r=xi+yi+zk

[0111] Where r is the vector path, x, y, z are the coordinate parameters of the moving particle in the non-inertial reference system, i, j, k are the unit vectors in the non-inertial reference system, and the unit vector does not change with time. That is, in the non-inertial reference system, the derivative of the unit vector with respect to the preset time is 0, that is:

[0112]

[0113] Among them, the symbol Represents the differential operation in a non-inertial reference frame.

[0114] The following calculation formulas all use mathematical formula symbols with marking symbols to represent the calculation results relative to the non-inertial reference frame, for example: v,.

[0115] That is, the unit vector is a constant modulus vector in the non-inertial reference frame, so, where w0 is the angular velocity between the two reference frames, in the inertial reference frame:

[0116]

[0117] For example, in two reference frames, there is a mutual conversion relationship when calculating the derivative of the same vector with respect to time. For example, in an inertial reference frame and a non-inertial reference frame, the derivatives of the same vector A with respect to time are calculated as follows:

[0118]

[0119] Combining the above calculation steps, we can conclude that the relationship between the differential of vector A with respect to time in the two reference frames is:

[0120]

[0121] The operator transformation relationship for differentiating the time quotient between two reference frames rotating relative to each other at an angular velocity w0 (in the embodiment, w0 is the yaw angular velocity generated when the vehicle enters a curve) is:

[0122]

[0123] Based on the above formula, the calculation steps of absolute speed are:

[0124]

[0125] Further simplification of it yields:

[0126]

[0127] Exemplarily, after calculating the derivative of the vector path with respect to a preset time in the inertial reference system to obtain the absolute speed, the method further includes:

[0128] Step d: Calculate the derivative of the absolute velocity with respect to the preset time to obtain an absolute acceleration; the absolute acceleration is used to calculate the relative motion of the vehicle in the inertial reference system.

[0129] The method for calculating acceleration is to further calculate the known speed and calculate the derivative of the known speed with respect to time:

[0130]

[0131] Step S230: calculating the velocity of the reference target relative to the non-inertial reference frame based on the first position parameter and the yaw angular velocity;

[0132] The entrained velocity is the velocity generated when the non-inertial reference frame rotates around the inertial reference frame. This velocity is calculated and introduced into the calculation process to improve the motion state of the calculated reference target in the non-inertial reference frame.

[0133] Exemplarily, the calculating, based on the first position parameter and the yaw angular velocity, the drag velocity of the reference target relative to the non-inertial reference frame includes:

[0134] Step e: calculating the derivative of the vector path with respect to the preset time in the non-inertial reference frame to obtain a relative velocity;

[0135] The relative velocity is calculated by calculating the derivative of the vector path with respect to the preset time in the non-inertial reference frame.

[0136] The steps to calculate the relative velocity are:

[0137]

[0138] Step f: Calculating the difference between the absolute speed and the relative speed to obtain the involved speed;

[0139] Absolute speed = relative speed + drag speed, that is, v = v, + v t .

[0140] The implicated velocity can be obtained by calculating the difference between the absolute velocity and the relative velocity, or by summing up and simplifying the absolute velocity when calculating the absolute velocity to directly obtain the sum of the implicated velocity and the relative velocity, thereby obtaining the implicated velocity.

[0141] When the absolute speed is calculated, the calculation formula of the absolute speed is simplified to the following form:

[0142]

[0143] In this formula, v t =w0×r is the entrainment velocity.

[0144] After the entrained velocity is calculated, a cross product operation is performed on the entrained velocity according to the positive directions of the horizontal and vertical axes of the non-inertial reference system to obtain the horizontal and vertical axis entrained velocity in the non-inertial reference system, respectively. In addition, the horizontal and vertical axis relative velocities in the non-inertial reference system are calculated based on the relative velocity, the horizontal and vertical axis entrained velocities.

[0145] The calculated relative velocity and drag velocity in the horizontal and vertical directions of the non-inertial reference system are used to calculate the relative motion between the non-inertial reference system and the inertial reference system. After the relative motion is obtained, the motion state of the reference target in the non-inertial reference system is compensated accordingly to ensure that the motion state of the reference target is accurately calculated.

[0146] According to the theory of dynamics of non-inertial reference frame and inertial reference frame, the velocity involved due to the rotation and translation of the non-inertial reference frame is calculated. According to the cross product principle, the velocity involved in the positive direction of x and y is calculated as:

[0147]

[0148] In this calculation formula, V tx is the horizontal axis drag speed, V ty The vertical axis is the velocity.

[0149] Calculate the relative velocity between the non-inertial reference frame and the inertial reference frame. When the target ahead is stationary, the angular velocity and acceleration are 0. Combining the above formulas for calculating relative velocity, horizontal axis velocity, and vertical axis velocity, the relative velocity on the horizontal and vertical axes in the non-inertial reference frame is as follows:

[0150]

[0151] Exemplarily, after calculating the velocity of the reference target relative to the non-inertial reference frame based on the first position parameter and the yaw angular velocity, the method further includes:

[0152] Step g: respectively calculating the derivatives of the relative speed and the involved speed with respect to the preset time to obtain the relative acceleration and the involved acceleration;

[0153] Calculate the acceleration caused by the rotation and translation of the non-inertial reference frame:

[0154]

[0155] Based on the assumption that v0 is a uniform motion in a short period of time, the vehicle body rotates constantly at w0 in a short period of time. In this formula, v0 is the current speed of the vehicle, and w0 is the yaw angular velocity generated by the vehicle when entering a curve.

[0156] Then in the above formula:

[0157]

[0158]

[0159] Step h: Calculating the difference between the absolute acceleration, the relative acceleration, and the involved acceleration to obtain the Coriolis acceleration; the Coriolis acceleration is used to calculate the dynamic change between the non-inertial reference system and the inertial reference system;

[0160] Absolute acceleration = relative acceleration + implicated acceleration + Coriolis acceleration. Therefore, the difference between absolute acceleration, relative acceleration and implicated acceleration is calculated to obtain Coriolis acceleration.

[0161] Or when calculating the absolute acceleration, the Coriolis acceleration and the induced acceleration can be directly obtained by integrating and simplifying the calculation formula of the absolute acceleration.

[0162]

[0163] Where: The drag acceleration is:

[0164]

[0165] Where, the Coriolis acceleration is:

[0166] a c =2w0×v`

[0167] After the relative acceleration, the entrained acceleration and the Coriolis acceleration are calculated, the transverse acceleration and the longitudinal acceleration of the relative acceleration, the entrained acceleration and the Coriolis acceleration in the non-inertial reference frame are calculated respectively. The transverse acceleration and the longitudinal acceleration are used to compensate for the motion state of the calculation reference target in the non-inertial reference frame.

[0168] According to the cross product principle, the acceleration in the x and y directions can be calculated, where the acceleration in the horizontal direction is:

[0169] The direction is consistent with the y-axis

[0170] The direction is opposite to the x-axis

[0171] The direction is opposite to the x-axis

[0172] Similarly, calculate the acceleration in the vertical direction:

[0173]

[0174] Calculate the relative acceleration due to the rotation of the non-inertial reference frame, and the absolute acceleration of the static target is 0, and the calculation results are:

[0175]

[0176] Calculate the Coriolis acceleration due to the rotation and translation of the non-inertial reference frame.

[0177] According to the cross multiplication principle, the Coriolis acceleration in the x and y directions can be calculated:

[0178]

[0179] Step S240: Calculating a second position parameter of the reference target after the relative motion based on the absolute velocity and the involved velocity.

[0180] Based on the calculations from step c to step k above, calculate the position of the static target in the non-inertial reference frame at the current moment:

[0181]

[0182] The yawrate (yaw angular velocity) in the formula is the yaw angular velocity of the vehicle when entering a curve.

[0183] By establishing a dynamically changing non-inertial reference system with the vehicle as the coordinate origin, detecting the vehicle's current speed, first position parameter, and yaw angular velocity, and performing the above calculations, the second position parameter of the reference target can be obtained.

[0184] The calculation process involves the parameter values of relative velocity, involved velocity, relative acceleration, involved acceleration and Coriolis acceleration under non-inertial conditions, in order to comprehensively consider the rotation and translation generated between the non-inertial reference frame and the inertial reference frame, and improve the accuracy of calculating the motion state and motion trajectory of the reference target in the non-inertial reference frame.

[0185] In this embodiment, a non-inertial reference system is established with the vehicle as the coordinate origin, and the static coordinate system of the reference target is determined, that is, the inertial reference system in which the reference target is located is determined. The entrained velocity and entrained acceleration generated by the rotation of the non-inertial reference system around the inertial reference system are calculated. The relative velocity and relative acceleration of the reference target in the non-inertial reference system are also calculated. Parameters related to the motion of the moving particle, such as the absolute velocity, absolute acceleration, and Coriolis acceleration, are also calculated. By comprehensively considering the relative velocity and entrained velocity to the motion posture of the reference target in the non-inertial reference system, the dynamic changes of the vehicle driving in the curve can be accurately determined.

[0186] For example, refer to Figure 4 , Figure 4 : is a flow chart of the third embodiment of the target locking method of the present application. Based on the first and second embodiments of the target locking method of the present application, the third embodiment is proposed. The method further includes:

[0187] Step S310: Calculating a plurality of second position parameters of the reference target in the non-inertial reference frame based on a preset detection interval duration;

[0188] The preset detection interval uses the same time interval as the reference target detection interval, thereby enabling the vehicle's sensor to detect the reference target in multiple detection cycles. For example, the detection interval can be 1 second or 2 seconds. For example, a 1-second detection interval produces the same computational effect as a 1-second detection interval, and will not be further explained here.

[0189] Every time 1 second passes, the current position of the reference target is calculated. During each detection, the position parameters of the current position of the reference target are calculated, and multiple trajectory points of the reference target are determined based on multiple position parameters.

[0190] Step S320: fitting a motion trajectory curve of the reference target in the non-inertial reference frame based on the plurality of second position parameters;

[0191] According to the position parameters of multiple trajectory points, the position parameters are fitted, and the position parameters of the trajectory points with obvious deviations are excluded to form a smooth motion trajectory curve of the reference target in the non-inertial reference frame.

[0192] The motion trajectory curve is compensated accordingly in a fitting manner, so that the final effect presented by the motion trajectory curve is an approximation of the actual motion trajectory of the reference target in the non-inertial reference frame.

[0193] The motion trajectory curve is increased, adjusted or supplemented accordingly according to the trajectory points calculated each time.

[0194] Step S330: Outputting the motion trajectory curve to a vehicle-mounted sensor so that the sensor can predict the position of the reference target at the next moment.

[0195] The motion trajectory curve is output to the on-board sensor, which analyzes the curve and predicts its trend, analyzing the reference target's position at the next moment. This improves the accuracy of positioning the reference target and predicts its motion. This optimizes the prediction of the reference target's trajectory, making the predicted path closer to the actual trajectory.

[0196] In this embodiment, a non-inertial reference system is established, and periodic detection, calculation, and analysis are performed on the position parameter changes of the motion trajectory of the reference target in the non-inertial reference system, so as to predict the motion trajectory of the reference target in the non-inertial reference system, and then analyze the motion trajectory trend of the reference target in the non-inertial reference system at the next moment, thereby facilitating the locking and capture of the reference target by the vehicle's on-board sensors, and at the same time, optimizing the predicted motion trajectory of the reference target.

[0197] For example, refer to Figure 5 , Figure 5 : is a flow chart of a fourth embodiment of the target locking method of the present application. Based on the first, second and third embodiments of the target locking method of the present application, the fourth embodiment is proposed. The method further includes:

[0198] When the vehicle enters a curve, the target motion compensation calculation is triggered.

[0199] At this point, the vehicle's current speed and yaw rate are obtained, and the target motion posture is detected within a predetermined time period t. The above data is input into the algorithm.

[0200] After obtaining the corresponding data, determine whether the current speed of the vehicle is reasonable. If the current speed is too large or too small, the calculation effect of the benchmark target is poor or the calculation of the benchmark target is meaningless. Therefore, when the current speed of the vehicle is unreasonable, the target motion compensation calculation process is directly terminated. If the current speed is reasonable, the relevant data of the benchmark target is obtained.

[0201] Obtain relevant data for the reference target. This data is the coordinate parameters of the reference target, that is, the first position parameters of the reference target in the non-inertial reference frame. The reference target selected by the vehicle during driving is a static target by default, and this static target is the reference target.

[0202] After obtaining the relevant data, the corresponding motion compensation calculation is performed on the relevant data, wherein the motion compensation calculation includes calculating the reference target's X-axis and Y-axis velocity, relative velocity, reference acceleration, Coriolis acceleration and relative acceleration in the non-inertial reference frame.

[0203] After calculating the content required for motion compensation calculation, the position of the reference target in the non-inertial reference frame is calculated in combination with the above-mentioned velocity and acceleration parameters, that is, the second position parameter of the reference target in the non-inertial reference frame is calculated.

[0204] After all the above calculation steps are completed, the second position parameters of the reference target are obtained. At this time, the target motion compensation calculation process is completed and the calculation step is ended. If the above calculation steps are not completed, the relevant calculation of velocity or acceleration is continued until all the calculation steps are completed.

[0205] In addition, the present application also provides a target motion compensation calculation device, wherein the target locking device includes:

[0206] A first acquisition module is used to acquire the current speed of the vehicle and the yaw rate of the vehicle;

[0207] Establishment module: used for establishing a dynamically changing non-inertial reference system with the vehicle as the coordinate origin;

[0208] A second acquisition module is configured to acquire a reference target located in front of the vehicle and acquire a first position parameter of the reference target in the non-inertial reference system when the speed is within a preset vehicle speed range;

[0209] A calculation module is configured to calculate a second position parameter of the reference target after relative motion based on the non-inertial reference system, the first position parameter, and the yaw angular velocity.

[0210] Exemplarily, the calculation module includes:

[0211] A determination submodule: configured to determine the inertial reference frame where the reference target is located based on the first position parameter;

[0212] A first calculation submodule: configured to calculate an absolute speed of the vehicle relative to the inertial reference system based on the first position parameter;

[0213] A second calculation submodule is configured to calculate the velocity of the reference target relative to the non-inertial reference system based on the first position parameter and the yaw angular velocity;

[0214] The third calculation submodule is configured to calculate, based on the absolute velocity and the involved velocity, a second position parameter of the reference target after the relative motion occurs.

[0215] Exemplarily, the determining submodule includes:

[0216] A first selection unit is configured to use the vehicle as a moving mass point for calculating velocity and acceleration; the moving mass point is used to calculate the driving conditions of the vehicle in the non-inertial reference system and the inertial reference system;

[0217] A second selection unit is configured to use a path from the vehicle to the reference target as a vector path of the moving particle; wherein the vector path is used to calculate the motion of the moving particle in different coordinate systems.

[0218] Exemplarily, the first calculation submodule includes:

[0219] A first calculation unit is configured to calculate the derivative of the vector path with respect to a preset time in the inertial reference system to obtain an absolute speed;

[0220] The second calculation unit is used to calculate the derivative of the absolute speed with respect to the preset time to obtain the absolute acceleration; the absolute acceleration is used to calculate the relative motion of the vehicle in the inertial reference system.

[0221] Exemplarily, the second calculation submodule includes:

[0222] A fourth calculation unit is configured to calculate the derivative of the vector path with respect to the preset time in the non-inertial reference frame to obtain a relative speed;

[0223] A fifth calculation unit is configured to calculate the difference between the absolute speed and the relative speed to obtain the involved speed;

[0224] a sixth calculation unit, configured to respectively calculate the derivatives of the relative speed and the involved speed with respect to the preset time to obtain a relative acceleration and an involved acceleration;

[0225] a seventh calculation unit, configured to calculate the difference between the absolute acceleration, the relative acceleration, and the involved acceleration to obtain Coriolis acceleration; the Coriolis acceleration is used to calculate the dynamic change between the non-inertial reference system and the inertial reference system;

[0226] Exemplarily, the calculation module includes:

[0227] A fourth calculation submodule: configured to calculate a plurality of second position parameters of the reference target in the non-inertial reference frame based on a preset detection interval duration;

[0228] A fitting submodule: configured to fit a motion trajectory curve of the reference target in the non-inertial reference frame based on the plurality of second position parameters;

[0229] Output submodule: used to output the motion trajectory curve to the vehicle-mounted sensor so that the sensor can predict the position of the reference target at the next moment.

[0230] The specific implementation of the target motion compensation calculation device of the present application is basically the same as the embodiments of the above-mentioned target locking method, and will not be repeated here.

[0231] In addition, this application also provides a target locking device. Figure 6 As shown, Figure 6 It is a structural diagram of the hardware operating environment involved in the embodiment of the present application.

[0232] For example, Figure 6 This is a structural diagram of the hardware operating environment of the target motion compensation computing device.

[0233] like Figure 6 As shown, the target motion compensation calculation device may include a processor 601, a communication interface 602, a memory 603 and a communication bus 604, wherein the processor 601, the communication interface 602 and the memory 603 communicate with each other via the communication bus 604, the memory 603 is used to store computer programs; the processor 601 is used to implement the steps of the target locking method when executing the program stored in the memory 603.

[0234] The communication bus 604 mentioned in the target motion compensation computing device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 604 can be divided into an address bus, a data bus, and a control bus. For ease of illustration, the figure shows only one thick line, but this does not mean that there is only one bus or only one type of bus.

[0235] The communication interface 602 is used for communication between the target motion compensation calculation device and other devices.

[0236] The memory 603 may include a random access memory (RMD) or a non-volatile memory (NM), such as at least one disk storage. Alternatively, the memory 603 may be at least one storage device located away from the processor 601.

[0237] The above-mentioned processor 601 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0238] The specific implementation of the target motion compensation calculation device of the present application is basically the same as the embodiments of the above-mentioned target locking method, and will not be repeated here.

[0239] In addition, an embodiment of the present application further proposes a computer-readable storage medium, on which a target motion compensation calculation program is stored. When the target motion compensation calculation program is executed by a processor, the steps of the target locking method described above are implemented.

[0240] The specific implementation of the computer-readable storage medium of the present application is basically the same as the above-mentioned embodiments of the target locking method, and will not be repeated here.

[0241] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0242] The serial numbers of the above embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0243] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present application.

[0244] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A target locking method, characterized in that: The target locking method comprises the following steps: Get the vehicle's current speed and yaw rate; establishing a non-inertial reference system with the vehicle as a coordinate origin, wherein the non-inertial reference system deflects around the same coordinate origin of an inertial reference system relative to the non-inertial reference system based on the yaw angular velocity; When the speed is within a preset vehicle speed range, obtaining a reference target located in front of the vehicle, and obtaining a first position parameter of the reference target in the non-inertial reference system; Based on the non-inertial reference system, the first position parameter, and the yaw angular velocity, a second position parameter of the reference target in the non-inertial reference system is calculated to determine the position of the reference target based on the second position parameter; wherein the second position parameter is the current position parameter of the reference target in the non-inertial reference system when the reference target moves relative to the vehicle during driving of the vehicle, and the second position parameter is used to lock the reference target.

2. The target locking method according to claim 1, wherein: The calculating, based on the non-inertial reference system, the first position parameter, and the yaw angular velocity, to obtain a second position parameter of the reference target after the relative motion occurs includes: Determining an inertial reference frame in which the reference target is located based on the first position parameter; calculating an absolute velocity of the vehicle relative to the inertial reference system based on the first position parameter; calculating a velocity of the reference target relative to a non-inertial reference frame based on the first position parameter and the yaw angular velocity; Based on the absolute speed and the involved speed, a second position parameter of the reference target after the relative motion is obtained by calculation.

3. The target locking method according to claim 2, characterized in that: After determining the inertial reference frame where the reference target is located based on the first position parameter, the method further includes: The vehicle is used as a moving mass point; the moving mass point is used to calculate the driving conditions of the vehicle in the non-inertial reference system and the inertial reference system; The path from the vehicle to the reference target is used as the vector path of the moving particle; wherein the vector path is used to calculate the motion of the moving particle in different coordinate systems.

4. The target locking method according to claim 3, characterized in that: Calculating the absolute speed of the vehicle relative to the inertial reference system based on the first position parameter includes: In the inertial reference system, calculating the derivative of the vector path with respect to a preset time to obtain an absolute velocity; After calculating the derivative of the vector path with respect to a preset time in the inertial reference system to obtain the absolute velocity, the method further includes: The derivative of the absolute speed with respect to the preset time is calculated to obtain an absolute acceleration; the absolute acceleration is used to calculate the relative motion of the vehicle in the inertial reference frame.

5. The target locking method according to claim 4, characterized in that: The calculating, based on the first position parameter and the yaw angular velocity, the velocity of the reference target relative to the non-inertial reference system includes: In the non-inertial reference frame, calculating the derivative of the vector path with respect to the preset time to obtain a relative velocity; The difference between the absolute speed and the relative speed is calculated to obtain the involved speed.

6. The target locking method according to claim 5, characterized in that: After calculating the velocity of the reference target relative to the non-inertial reference frame based on the first position parameter and the yaw angular velocity, the method further comprises: respectively calculating derivatives of the relative speed and the involved speed with respect to the preset time to obtain relative acceleration and involved acceleration; The difference between the absolute acceleration, the relative acceleration and the involved acceleration is calculated to obtain the Coriolis acceleration; the Coriolis acceleration is used to calculate the dynamic change between the non-inertial reference system and the inertial reference system.

7. The target locking method according to claim 6, characterized in that: After calculating the second position parameter of the reference target after the relative motion occurs based on the absolute speed and the involved speed, the method includes: Calculating a plurality of second position parameters of the reference target in the non-inertial reference frame based on a preset detection interval duration; Fitting a motion trajectory curve of the reference target in the non-inertial reference frame based on the multiple second position parameters; The motion trajectory curve is output to a vehicle-mounted sensor so that the sensor can predict the position of the reference target at the next moment.

8. A target locking device, characterized in that: The target locking device is a step for implementing the target locking method according to any one of claims 1 to 7, and the target locking device includes: A first acquisition module is used to acquire the current speed of the vehicle and the yaw rate of the vehicle; Establishment module: used for establishing a dynamically changing non-inertial reference system with the vehicle as the coordinate origin; A second acquisition module is configured to acquire a reference target located in front of the vehicle and acquire a first position parameter of the reference target in the non-inertial reference system when the speed is within a preset vehicle speed range; A calculation module is configured to calculate a second position parameter of the reference target after relative motion based on the non-inertial reference system, the first position parameter, and the yaw angular velocity.

9. A target locking device, characterized in that: The device includes: a memory, a processor, and a target motion compensation calculation program stored in the memory and executable on the processor, wherein the target motion compensation calculation program is configured to implement the steps of the target locking method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a target motion compensation calculation program, which, when executed by a processor, implements the steps of the target locking method according to any one of claims 1 to 7.

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