A local path decision control method, a rice transplanter control system, and a rice transplanter

Abstract

The application discloses a local path decision control method, a rice transplanter control system and a rice transplanter. It relates to the technical field of rice transplanter control. The application can complete position calibration and line planning adjustment. The application plans the speed and control points of the subsequent line, so that the rice transplanter can have efficiency and safety during operation. The application improves the transplanter speed, controls the speed of the transplanter at the turning point, and avoids the collision with the ridge and other risks caused by the too fast speed of the transplanter. Furthermore, the application also plans a local joining path of the transplanter, solves the problem of resuming after interruption in the transplanter process, and is suitable for all transplanter with automatic navigation function, and has the advantages of improving the safety and efficiency of the transplanter.

Description

Technical Field

[0001] This invention relates to the field of rice transplanter control technology, and more specifically, to a local path decision control method, a rice transplanter control system, and a rice transplanter. Background Technology

[0002] A rice transplanter is an agricultural machine that plants rice seedlings into paddy fields. With the continuous development of autonomous driving technology and related control technology, the use of automatic rice transplanting technology is becoming increasingly widespread. The main problem that existing automatic rice transplanting technology focuses on is path planning, that is, to achieve maximum coverage of rice seedlings in the field by planning the operating path of the rice transplanter.

[0003] After path planning, the rice transplanter needs to calibrate its current position during the execution of the planned path and adjust the subsequent path based on the calibration results. Furthermore, to ensure high-efficiency transplanting, the transplanter's operating speed and seedling claw control points along the planned route also need further planning. Current technology primarily focuses on adjusting the transplanting path, but does not provide effective planning methods for position correction and speed control within the path. Summary of the Invention

[0004] This invention overcomes the shortcomings of existing technologies in path correction and movement speed control, and provides a local path decision control method, a rice transplanter control system, and a rice transplanter, in order to solve the problems existing in the prior art.

[0005] To address the aforementioned technical problems, one aspect of the present invention provides a local path decision control method:

[0006] A local path decision control method includes the following steps:

[0007] Determine the vehicle's current position and heading, and its local path.

[0008] Based on the vehicle's current location, point C, the subsequent path is planned into a fast segment, a slow segment, an acceleration segment, a deceleration segment, and a precise control segment, and the vehicle's throttle and / or speed are controlled according to the path plan.

[0009] A further technical solution is that determining the local path where the vehicle's current position and heading are located specifically includes the following steps:

[0010] The rice transplanting trajectory in the paddy field is planned as a concatenation of a straight path (path) and a U-turn path (u-turn);

[0011] Calculate the projection point P from point C onto the nearest rice planting path, i.e., the projection.

[0012] Calculate the vector from point C to the center of the U-turn path, ou. ( ):

[0013] ;

[0014] In the formula, Δx c The distance in the X direction from point C to point ou;

[0015] x C Here is the X-coordinate of point C;

[0016] x ou Let ou be the X-coordinate of point ou.

[0017] In the formula, Δy c The distance in the Y direction from point C to point ou;

[0018] y C Here is the Y-coordinate of point C;

[0019] y ou Let ou be the Y-coordinate of point ou.

[0020] Normalization yields vectors ( ):

[0021] ;

[0022] In the formula, Δx p The distance in the X direction from point P to point ou;

[0023] Δy p The distance in the Y direction from point P to point ou;

[0024] distance ouC The distance from point Ou to point C;

[0025] w represents the width of the rice transplanter;

[0026] ;

[0027] In the formula, x p Let P be the X-coordinate of point P;

[0028] y p Let P be the Y-coordinate of point P;

[0029] Calculate vectors and cross product vector U2 ;

[0030] ;

[0031] In the formula, U2 is a point on the semicircular arc;

[0032] For U2 to the start of the turn U Start ;

[0033] For U2 to the end of the turn U End ;

[0034] Calculate vectors and cross product vector p ;

[0035] ;

[0036] In the formula, From point P to the start of the turn U Start ;

[0037] From point P to the end of the turn U End ;

[0038] when and When the license plate number is the same, the vehicle is on a U-turn route;

[0039] when and When the license plate number is different, the vehicle is on a straight path.

[0040] A further technical solution is that, based on the vehicle's current location point C, the subsequent path is planned into a fast segment, a slow segment, an acceleration segment, a deceleration segment, and a precise control segment, and the vehicle's throttle and / or speed is controlled according to the path plan, specifically including the following steps;

[0041] The rice transplanting trajectory in the paddy field is planned as a concatenation of a straight path (path) and a U-turn path (u-turn);

[0042] The straight path is divided into fast section, slow section, acceleration section, and deceleration section, and the vehicle is controlled according to the set road sections.

[0043] The remaining path is planned as a precise control segment, slowing down the vehicle when it approaches the U-turn path and accelerating it when it moves away from the U-turn path.

[0044] A further technical solution is that the speed control method for the precise control segment is as follows:

[0045] Detect the nearest turn start point (U) to point P. Start ) or at the end of the turn (U End The distance dis_P_SP from point P is the nearest starting point of the turn (U). Start ) or at the end of the turn (U End) is the stoppoint;

[0046] When the distance dis_P_SP is less than the threshold (dis_P_SP_max), the following throttle control is enabled:

[0047] ;

[0048] In the formula, throttle command Throttle control command;

[0049] k is a control parameter;

[0050] para_throttle_min is the controllable minimum throttle, which is greater than the idle throttle;

[0051] para_throttle_norm is the normal throttle setting.

[0052] A further technical solution is that the path execution strategy planning method also includes the following steps:

[0053] The rice transplanting trajectory in the paddy field is planned as a concatenation of a straight path (path) and a U-turn path (u-turn);

[0054] Plan the lifting point and landing point of the seedling carrier platform in the straight path, and control the lifting of the seedling carrier platform at the lifting point and control the landing of the seedling carrier platform at the landing point.

[0055] A further technical solution is that the planned seedling platform lifting point and seedling platform landing point specifically include one of the following solutions;

[0056] Option 1:

[0057] When the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is greater than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, the situation is state 0.

[0058] When in state 0, the lifting point of the seedling platform is the last intersection of the seedling claw of the seedling platform with the working boundary, and the landing point of the seedling platform is the intersection of the seedling platform and the exit point of the turning path.

[0059] When the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is less than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, this situation is state 1.

[0060] In state 1, the lifting point of the seedling platform is the intersection of the seedling platform and the turning point of the turning path, and the landing point of the seedling platform is the initial intersection of the seedling claw of the seedling platform and the working boundary.

[0061] Option 2:

[0062] Calculate the starting point (Line_Start) of the straight part of the J-shaped local path spliced ​​by each straight path and U-turn path. Set the fixed distance outside the starting point of the straight part as the early landing point of the seedling loading platform (P_down_early). The working range of the seedling loading platform from the early landing point of the seedling loading platform to the end point of the straight part of the path (Line_End) is the working range of the seedling loading platform in the current working row.

[0063] Option 3:

[0064] The seedling claws are controlled in real time;

[0065] Option 4:

[0066] Define the seedling claw early closing distance parameter (d_ClawClose_early). Each seedling claw is located outside the seedling claw closing point, and the seedling claw closing operation is performed at the distance of the early closing distance parameter.

[0067] Option 5:

[0068] Switch between manual and automatic modes. When in automatic mode, use any one of the above schemes from one to four for control.

[0069] When operated manually, it is controlled by a person.

[0070] A further technical solution involves lateral control of vehicle movement to prevent the vehicle from deviating laterally from its path.

[0071] A further technical solution is to plan a local addition path when the first row is online or when the operation is interrupted and the i-th row is brought online again;

[0072] The local addition path is a straight line segment from a point a certain distance outside the starting point of the straight line operation row to the starting point of that row.

[0073] The planned partial inclusion path specifically includes the following steps:

[0074] The search vehicle was determined to be on the rice planting path;

[0075] If the path is determined to be a rice planting path, then the trajectory of that rice planting path will be executed.

[0076] If the rice planting path is not determined, the nearest local entry path for the vehicle is calculated, and the vehicle enters the rice planting path trajectory through the local entry path.

[0077] A further technical solution is that, if the location is within the rice planting path, the trajectory of the rice planting path is executed; specifically, this includes the following steps:

[0078] The rice transplanting trajectory in the paddy field is planned as a concatenation of a straight path (path) and a U-turn path (u-turn);

[0079] If the vehicle is determined to be on a straight path within the rice planting route, continue executing the straight path directly.

[0080] If the vehicle is determined to be on a U-turn path from the rice planting route, the current U-turn path number is obtained, and the current U-turn path is tracked.

[0081] In another aspect, the present invention also provides a rice transplanter control system;

[0082] The rice transplanter control system executes the local path decision control method described above, including:

[0083] A positioning module, which is used to locate the current position and heading of the rice transplanter;

[0084] The planning module is used to obtain the planned path of the plot, determine the local path where the vehicle is currently located and heading, and plan the subsequent path into fast segment, slow segment, acceleration segment, deceleration segment and precise control segment;

[0085] A control module is used to control the vehicle's movement according to a planned path and direction.

[0086] In another aspect, the present invention also provides a rice transplanter;

[0087] Rice transplanter, including the rice transplanter control system described above.

[0088] Compared with existing technologies, the present invention has at least the following beneficial effects: On the one hand, the present invention can complete the position calibration and route planning adjustment of the rice transplanter; on the other hand, the present invention plans the speed and control points of the subsequent route, enabling the rice transplanter to achieve both efficiency and safety during operation. It improves the transplanting speed while controlling the speed of the rice transplanter at turning points, avoiding collisions with field ridges and other risks caused by excessive speed. Furthermore, this application also plans a partial insertion path for transplanting, solving the problem of recovery after interruption of the seedling claw process. This application is applicable to all rice transplanters with automatic navigation functions, and has the advantage of improving transplanting safety and efficiency. Attached Figure Description

[0089] Figure 1 This is a partial path diagram showing the current position and heading of the rice transplanter.

[0090] Figure 2 A schematic diagram illustrating the calculation process for determining the vehicle's current position and heading.

[0091] Figure 3 A schematic diagram of the planned route segment and control points of the rice transplanting platform in state 0;

[0092] Figure 4This is a schematic diagram of the planned route for rice transplanting in state 1 and the control points of the transplanting platform.

[0093] Figure 5 A schematic diagram illustrating the process of determining the StopPoint for calculating dis_P_SP at each point; dis_P_SP is the shortest distance among the four distances from the vehicle's current point P to the four StopPoints on the nearest path;

[0094] Figure 6 This is a schematic diagram illustrating the rice transplanting effect of a rice transplanter in a paddy field when the state is 0.

[0095] Figure 7 This is a schematic diagram illustrating the rice transplanting effect of a rice transplanter in state 1.

[0096] Figure 8 This is a path diagram when property12=0;

[0097] Figure 9 This is a path diagram when property12=1;

[0098] Figure 10 A schematic diagram of path planning is added to the local area. Detailed Implementation

[0099] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0100] Example 1

[0101] It should be noted in advance that, generally speaking, a rice transplanter consists of a four-wheeled vehicle body and a seedling platform. In the following text, the outer contour of the four-wheeled vehicle body is equivalent to a rectangle, and the control point of the vehicle body (the center of the rear wheel axle) is taken as the most fundamental position reference point. It can be understood that other positions of the vehicle body or seedling platform can also be used as reference points.

[0102] A local path decision control method includes the following steps:

[0103] S1. Determine the vehicle's current position and heading within the local path;

[0104] See Figure 1 , Figure 1 Point C is the current location of the rice transplanter, and point P is the projection of point C onto the nearest transplanting path. f This indicates the current direction of travel of the rice transplanter;

[0105] To better illustrate the different situations, in Figure 1Two points C are marked in the diagram, and the same calculation method will be used for both in subsequent calculations.

[0106] The determination of the vehicle's current position and heading along the local path specifically includes the following steps:

[0107] The rice transplanting trajectory in the paddy field is planned as a combination of a straight path and a U-turn path;

[0108] Calculate the projection point P from point C onto the nearest rice planting path, i.e., the projection.

[0109] Calculate the vector from point C to the center of the U-turn path, ou. ( (Refer to the appendix for the positional relationships of each point during the calculation process) Figure 2 ;

[0110] ;

[0111] In the formula, Δx c The distance in the X direction from point C to point ou;

[0112] x C Here is the X-coordinate of point C;

[0113] x ou Let ou be the X-coordinate of point ou.

[0114] In the formula, Δy c The distance in the Y direction from point C to point ou;

[0115] y C Here is the Y-coordinate of point C;

[0116] y ou Let ou be the Y-coordinate of point ou.

[0117] Normalization yields vectors ( ):

[0118] ;

[0119] ;

[0120] In the formula, Δx p The distance in the X direction from point P to point ou;

[0121] Δy p The distance in the Y direction from point P to point ou;

[0122] distance ouC The distance from point Ou to point C;

[0123] w represents the width of the rice transplanter;

[0124] ;

[0125] ;

[0126] In the formula, x p Let P be the X-coordinate of point P;

[0127] y p Let P be the Y-coordinate of point P;

[0128] Calculate vectors and cross product vector U2 ;

[0129] ;

[0130] In the formula, U2 is U End To U Start A point between, generally taken as U Start To U End At the 1 / 6 mark of the path, in this embodiment, U2 is U Start To U End See point 1 / 6 on the path. Figure 2 .

[0131] For U2 to the start of the turn U Start ;

[0132] For U2 to the end of the turn U End ;

[0133] Calculate vectors and cross product vector p ;

[0134] ;

[0135] In the formula, From point P to the start of the turn U Start ;

[0136] From point P to the end of the turn U End ;

[0137] when and When the license plate number is the same, the vehicle is on a U-turn route;

[0138] when and When the license plate number is different, the vehicle is on a straight path.

[0139] Furthermore, vectors It contains the vehicle's steering, when When it is "-", the vehicle turns counterclockwise, corresponding to a left turn; when When it is "+", the vehicle turns clockwise, and the corresponding steering method is: right turn.

[0140] After determining the vehicle's location, it is necessary to further combine the judgment function to determine the vehicle's driving direction, path angle, and distance;

[0141] For straight paths, the judgment function vehicle_between_LinePath is used. The specific judgment conditions are: if the angle between the vehicle and the straight line is within 60°, the distance is within ±1m, and the projection point is between the straight line segments, then it is judged to be within the path range; otherwise, it is not.

[0142] For the U-turn path, the judgment function vehicle_between_SemiCirclePath is used. The specific judgment conditions are: if point P is located on the same side of the semicircle as U2, and the distance from the semicircle is less than 0.5m, and the heading deviation is less than ±30°, then it is judged to be within the path range; otherwise, it is not.

[0143] If the system is determined to be within the path range, proceed with the next steps and continue autonomous driving; if it is determined to be outside the path range, exit autonomous driving.

[0144] S2. Based on the vehicle's current location, point C, plan the subsequent path into a fast segment, a slow segment, an acceleration segment, a deceleration segment, and a precise control segment, and control the vehicle's throttle and / or speed according to the path plan.

[0145] Specifically, it includes the following steps;

[0146] S21. Plan the rice planting trajectory in the paddy field as a combination of a straight path (path) and a turning path (u turn);

[0147] S22. Divide the straight path into fast section, slow section, acceleration section and deceleration section, and control the vehicle according to the set road section.

[0148] See Figure 3 and Figure 4 The acceleration segment is defined as the period from the maximum throttle start point Line_Vmax_Start to the maximum speed point P_speed_up. Figure 3 D in SpeedUp The period from the maximum throttle stop point P_speed_down to the normal throttle start point Line_Vmax_End is the deceleration phase (i.e. Figure 3D in SpeedDown );

[0149] For example, in this embodiment, the speed in the fast segment is Vmax (90% throttle) and the speed in the slow segment is Vmin (30%).

[0150] In a preferred embodiment, the directed distance from Line_Vmax_Start to Line_Vmax_End is greater than a threshold Slong. For example, acceleration can only be completed when the distance from Line_Vmax_Start to Line_Vmax_End exceeds 3 meters.

[0151] The specific length of the above-mentioned road segment can be set according to the decision conditions. For example, the distance from the start point of the straight path (Line_Start) to the start point of the maximum throttle (Line_Vmax_Start) is the length from when the seedling claw starts working to when all seedling claws start working; the distance from the start point of the maximum throttle (Line_Vmax_Start) to the maximum speed point (P_speed_up) is the length of acceleration to the maximum speed. The setting of this distance is related to the characteristics of the vehicle itself; the distance from the start point of the normal throttle (Line_Vmax_End) to the stop point of the maximum throttle (P_speed_down) is a fixed distance, which is set manually and is generally 1 meter; the distance from the start point of the normal throttle (Line_Vmax_End) to the end point of the straight path (Line_End) is the distance from when one group of seedling claws stops working to when all seedling claws stop working.

[0152] It should be noted that the transplanting point and the stopping point can change depending on the relationship between the working boundary and the trajectory of the rice transplanter. Figure 3 and Figure 4 The length and starting position of the straight path (from Line_Start to Line_End) and the precise control segment (from Line_End to the end of the path) differ. Specific control methods and planting point planning will be explained in subsequent steps.

[0153] Where Line_Start is the starting point of rice planting, and Line_End is the ending point of rice planting.

[0154] S23. The remaining path is planned as a precise control segment, decelerating when the vehicle approaches the U-turn path and accelerating when it moves away from the U-turn path.

[0155] It is understood that in this embodiment, the straight path portion and the entire U-turn path are planned as precise control segments;

[0156] For example, when the speed at the start and end points of a semi-circular arc is very small or zero (15% throttle, the reason being to accurately stop and steer, avoiding collisions with the boundary of the plot, which would cause the autonomous driving to fail), the throttle size can be controlled by detecting the distance to the start and end points.

[0157] In a preferred embodiment, the precise control segment speed control method is as follows:

[0158] Detect the nearest turn start point U to point P Start Or at the end of the turn U End The distance dis_P_SP, the nearest U to point P Start or U End For StopPoint;

[0159] Specifically, in P n When selecting a point, it is necessary to consider the distance P. n Point U at the start of the turn on the two nearest U-turn paths Start Or at the end of the turn U End The distances between these four points are calculated, and the distance P is the distance between them. n The nearest one is SP. n Point, see Figure 5 Taking P1 as an example, P1 is the current position of the rice transplanter, and SP1 is the nearest U to P1. Start or U End That is, StopPoint;

[0160] P2 is the current position of the rice transplanter, and SP2 is the nearest U to point P2. Start or U End ;

[0161] P3 is the current position of the rice transplanter, and SP3 is the nearest U to point P3. Start or U End ;

[0162] When the distance dis_P_SP is less than the threshold dis_P_SP_max (in this embodiment, dis_P_SP_max is set to 2m), the following throttle control is enabled:

[0163] ;

[0164] In the formula, throttle command Throttle control command;

[0165] k is a control parameter;

[0166] para_throttle_min is the controllable minimum throttle, which is greater than the idle throttle;

[0167] para_throttle_norm is the normal throttle setting.

[0168] For example, para_throttle_min is slightly larger than the idle throttle of the rice transplanter, such as 15%, to ensure that even if point P and StopPoint coincide (dis_P_SP=0), the vehicle can still drive away from StopPoint.

[0169] The para_throttle_norm value is set to around 30%.

[0170] With the above design, the start and end points of the semi-circular arc of the U-turn act like two attractors. The closer the vehicle's point P is to the StopPoint, the slower its speed becomes, and the faster it becomes when it moves away from the StopPoint. By adjusting the values ​​of k and para_throttle_min, good results can be obtained.

[0171] It should be noted that in order to further improve the rice transplanting coverage and avoid collisions between the seedling trays and the field ridges, the seedling trays need to be controlled during the process.

[0172] It should be noted that the transplanting platform can be controlled using any of the following methods:

[0173] Option 1:

[0174] The rice transplanting trajectory in the paddy field is planned as a concatenation of a straight path (path) and a U-turn path (u-turn);

[0175] Plan the lifting point and landing point of the seedling carrier platform in the straight path, and control the lifting of the seedling carrier platform at the lifting point and control the landing of the seedling carrier platform at the landing point.

[0176] The planned seedling platform lifting point and seedling platform landing point specifically include the following steps;

[0177] When the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is greater than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, the state of path 12 is 0 (Property12=0).

[0178] Wherein, path 12 (Property12) represents the path between points 1 and 2, and =0 represents a straight line; path 23 (Property23) represents the path between points 2 and 3, and =1 represents an arc.

[0179] See Figure 8 Set the first intersection point of the rice transplanter's working path and the working boundary to 1, the intersection point of the rice transplanter's working path and the semi-circular turning path to 2, and the last intersection point of the rice transplanter's working path and the semi-circular turning path to 3.

[0180] When the status of path 12 is 0 (Property12=0), the first half of the turning path is a straight line;

[0181] At this point, the movement mode and control points of the rice transplanter are described in [reference needed]. Figure 6 , Figure 6 There are two rice transplanters in different positions. The rice transplanter includes the rice transplanter body ( Figure 6 The black box in the middle) and the seedling claw component ( Figure 6 The green nodes on the seedling claw assembly (a green T-shaped structure) represent the left, middle, and right seedling claws. It's understood that the actual number of seedling claws may not be three. The lifting point of the seedling platform is the intersection of the seedling claws with the work boundary, and the landing point is the intersection of the seedling platform with the exit point of the turning path.

[0182] Understandably, at the seedling platform lifting point, it can be set to lift the vehicle at a short distance (for example, 0.1m) before the vehicle reaches the last intersection of the seedling claw of the seedling platform with the working boundary. The short distance is the distance from the seedling platform lifting point (P_up_early) to the last intersection of the seedling claw of the seedling platform with the working boundary.

[0183] In fact, there is a possibility that as soon as the level is increased, the rice planting will stop, so P_up_early can be ignored in the early stage.

[0184] The following explanation combines different states, throttle control methods, and road segment condition diagrams. The road segment planning reference is for state 0. Figure 3 Where Line_Start is the starting point of the straight path, and Line_Start to Line_Vmax_Start is the slow segment, with throttle control as described above;

[0185] The period from Line_Vmax_Start to P_speed_up is the acceleration segment, and the throttle control is from normal throttle to maximum allowable throttle.

[0186] The speed range from P_speed_up to P_speed_down is the high-speed segment, and the throttle control is at the maximum permissible throttle.

[0187] The period from P_speed_down to Line_Vmax_End is the deceleration phase, and the throttle control is from the maximum allowable throttle to the normal throttle.

[0188] The section from Line_Vmax_End to Line_End is the low-speed range, and the throttle control is the variable throttle as described above.

[0189] Line_End is the control point for lifting the rice planting platform. After passing this point, the precision control section begins, and the throttle is controlled by the formula in S23.

[0190] Rice transplanting effect reference Figure 6 .

[0191] Corresponding to the above situation, when the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is less than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, this situation is state 1.

[0192] See Figure 9 Set the first intersection point of the rice transplanter's working path and the semi-circular turning path to 1, and the second intersection point of the rice transplanter's working path and the semi-circular turning path to 2.

[0193] When the state of path 12 is 1 (Property12=1), the first half of the turning path is an arc; where Property12 represents the path between points 1 and 2, and =1 means it is an arc;

[0194] See Figure 7 The lifting point of the seedling platform is the intersection of the seedling platform and the turning point of the path, and the landing point of the seedling platform is the initial intersection of the seedling claw of the seedling platform and the working boundary.

[0195] Understandably, the landing point of the seedling carrier can be set to a short distance (for example, 1m) before the vehicle reaches the point where the seedling claw of the seedling carrier initially intersects with the working boundary, which is called an early landing.

[0196] If the distance from the end point of the semicircular arc to the descent point of the seedling platform is less than 1m, then P_down_early is set to the end point of the semicircular arc.

[0197] Road section planning reference for State 1 Figure 4 Where Line_Start is the starting point of the straight path, and Line_Start to Line_Vmax_Start is the slow segment, with throttle control as described above;

[0198] The period from Line_Vmax_Start to P_speed_up is the acceleration segment, and the throttle control is from normal throttle to maximum allowable throttle.

[0199] The speed range from P_speed_up to P_speed_down is the high-speed segment, and the throttle control is at the maximum permissible throttle. Figure 3 and Figure 4 Sections where the throttle is at 90%;

[0200] The period from P_speed_down to Line_Vmax_End is the deceleration phase, and the throttle control is from the maximum allowable throttle to the normal throttle.

[0201] The section from Line_Vmax_End to Line_End is the low-speed range, and the throttle control is the variable throttle as described above.

[0202] Line_End is the control point for lifting the rice planting platform. After passing this point, the precision control section begins, and the throttle is controlled by the formula in S23.

[0203] Figure 3 and Figure 4 D SpeedUp This is the acceleration phase, which is from the point where the maximum permissible throttle is applied to the point of maximum speed.

[0204] D SpeedDown This is the deceleration phase, from the maximum permissible throttle end point to the norm throttle point;

[0205] Rice transplanting effect reference Figure 7 .

[0206] Option 2:

[0207] Calculate P_down_early, a fixed distance from the outer edge of Line_Start, of the J-shaped local path formed by splicing the straight path and the U-turn path. The working interval of the seedling platform from P_down_early to Line_End is the current work row. For example, you can directly use a C++ program to execute this.

[0208] Option 3:

[0209] The seedling claws are controlled in real time;

[0210] For example, the switching control is performed using the seedling claw intervals: the control interval for closing the right seedling claw clutch is from RightClaw_Start to RightClaw_End; the control interval for closing the middle seedling claw clutch is from MidClaw_Start to MidClaw_End; and the control interval for closing the left seedling claw clutch is from LeftClaw_Start to LeftClaw_End.

[0211] Option 4:

[0212] Define the seedling claw early closing distance parameter d_ClawClose_early. Each seedling claw is located outside the seedling claw closing point, and the seedling claw closing operation is performed at the distance of the early closing distance parameter.

[0213] For example, the seedling claws include the left seedling claw (LeftClaw), the middle seedling claw (MidClaw), and the right seedling claw (RightClaw). The closing start points of the left seedling claw, the middle seedling claw, and the right seedling claw are LeftClaw_Start, MidClaw_Start, and RightClaw_Start, respectively. The seedling claw closing operation is performed outside the above closing start points by a closing distance parameter (d_ClawClose_early).

[0214] Option 5:

[0215] Switch between manual and automatic modes. When in automatic mode, use any one of the above schemes from one to four for control.

[0216] When operated manually, it is controlled by a person.

[0217] For example, a switch button is added to the display screen. Whenever the system is powered on, indicating the user's intention to use automatic driving, it automatically switches to the automatic lifting mode. The user can click to exit automatic lifting. The manual / automatic switching for the seedling carrier is enabled (Status_ManShift = 1) and disabled (Status_ManShift = 0).

[0218] In this embodiment, the seedling claws of the planting platform can be raised and lowered independently, and are controlled using Scheme 1.

[0219] In a preferred embodiment, lateral control is applied to the vehicle's movement to prevent lateral deviation from the path. Specifically, a straight-line lateral control algorithm is used for straight segments, and a circular arc lateral control algorithm is used for semi-circular segments.

[0220] Understandably, lateral control algorithms can be used as needed.

[0221] In a preferred embodiment, when the first row is brought online or the operation is interrupted and then the i-th row is brought online again, a local addition path is planned, the principle of which is referred to Figure 10 It is worth noting that circular arc tracking and straight line tracking are not tracking methods, but rather refer to tracking objects that are circular arcs or straight lines.

[0222] The first line is online, which means the rice planting has started; returning to the i-th line is online, where i is the number of the interrupted line; that is, after the i-1 line is completed, the automatic driving is exited, the rice planting point is moved to add rice seedlings, and then the i-th line is online. These two situations are relatively common. There are also other situations where rice planting is interrupted. In this case, it is necessary to add a local path, which is actually a straight line segment.

[0223] The local addition path is a straight line segment from a point a certain distance outside the starting point of the straight line operation row to the starting point of that row.

[0224] The planned partial inclusion path specifically includes the following steps:

[0225] Whether a search vehicle is determined to be on the rice planting path depends on a combination of position and heading errors. For example, if the distance from the rice planting path is less than 0.5m and the heading deviation is less than ±30°, it is considered to be on the rice planting path.

[0226] If it is determined that the location is within the rice planting path, then the trajectory of the rice planting path will be executed.

[0227] If it is determined that the vehicle is not located on the rice planting path, the nearest local entry path is calculated, and the vehicle enters the rice planting path trajectory through the local entry path.

[0228] For example, a locally added path is defined as a straight line segment from a point a distance of length_LAP (e.g., 5m) outside the starting point of each straight line job row to the starting point of that row, collectively referred to as local_added_path.

[0229] The specific steps for planning and joining the path are as follows: when a vehicle starts working in the internal work area, first search whether the vehicle is located in the current local rice planting path (local_path).

[0230] Before searching, the rice planting trajectory in the paddy field needs to be planned as a concatenation of a straight path (path) and a U-turn path (u-turn).

[0231] It is understandable that after segmentation, the straight path and the U-turn path are numbered respectively; in the following explanation, ID_ROW_current_LP represents the row number of the current local path, ID_ROW_current_LAP represents the row number of the path added to the current local path; ID_ROW_current represents the local path number actually executed by the rice transplanter.

[0232] For example, ID_ROW_current_LP=1 means that the path is a local path numbered 1, and ID_ROW_current_LAP=1 means that the row number of the path added to the local path numbered 1 is 1.

[0233] If the search result indicates that the vehicle is not in the rice planting path, i.e., ID_ROW_current_LP=0 (i.e., ID_ROW_current_LP is the initial value of 0, indicating that the current row number was not found), further searching is required in the Add Path (LAP).

[0234] If a match is found, ID_ROW_current_LAP will have a specific row number. The rice transplanter joins the search path (LAP) and reaches the local path. At this point, the rice transplanter can determine the current local path number (ID_ROW_current_LP). The current local path row number ID_ROW_current is defined as the larger of ID_ROW_current_LP and ID_ROW_current_LAP. This determination method ensures that the rice transplanter's trajectory direction follows the direction in which the local path number gradually increases.

[0235] If the location is within the rice planting path, the trajectory of that rice planting path will be executed, specifically including the following steps:

[0236] If the vehicle is determined to be on a straight path within the rice planting route, continue executing the straight path directly.

[0237] If the vehicle is determined to be on a U-turn path from the rice planting route, the current U-turn path number is obtained, and the current U-turn path is tracked.

[0238] If the vehicle is determined not to be on the rice planting path, it is added to the nearest row by using a local added path (local_added_path) that leads to the starting point of the nearest row. After being added, the subsequent determination steps are executed.

[0239] Specifically, the following situations may occur when performing the above steps:

[0240] 1. If the vehicle initially initiates autonomous driving and is not on the local path, then ID_ROW_current_LP = 0. However, a local path (LAP) is added in line i, for example, ID_ROW_current_LAP = 10, so ID_ROW_current = 10. The vehicle travels along the locally added path in line 10 and arrives at the semicircle in line 9, where ID_ROW_current_LP = 9. But at this point, ID_ROW_current_LAP = 10. Again, because the line number ID_ROW_current of the current operation is the larger of ID_ROW_current_LP and ID_ROW_current_LAP, ID_ROW_current = 10, thus avoiding turning to the semicircle in line 9.

[0241] 2. If the vehicle initially starts autonomous driving, and in the semi-circular arc segment of line 9 of local_path, that is, vehicle point P is located on the same side of the semi-circular arc as U2, and the distance from the arc is less than 0.5m, and the heading deviation is less than ±30°, then ID_ROW_current_LP=9, ID_ROW_current_LAP=0, and ID_ROW_current=9, which is slightly different from case 1. In this case, the vehicle will track the semi-circular arc of line 9 instead of the straight path of line 10. Of course, this will slightly produce some tracking error.

[0242] The trained user should align the rice transplanter with the 10th row, just like the first row guide, and move the rice transplanter back a certain distance. This can effectively avoid the situation from happening, and moving back a certain distance also allows the seedling platform sufficient distance to lower.

[0243] 3. If the vehicle is in local_path, such as ID_ROW_current_LP=20 and ID_ROW_current_LAP=0, then ID_ROW_current=20, which is the usual case.

[0244] Example 2

[0245] A rice transplanter control system executes the local path decision control method described above;

[0246] include:

[0247] A positioning module, which is used to locate the current position and heading of the rice transplanter;

[0248] The planning module is used to obtain the planned path of the plot, determine the local path where the vehicle is currently located and heading, and plan the subsequent path into fast segment, slow segment, acceleration segment, deceleration segment and precise control segment;

[0249] A control module is used to control the vehicle's movement according to a planned path and direction.

[0250] Example 3

[0251] A rice transplanter includes, as described above, a rice transplanter control system.

[0252] Although the invention has been described herein with reference to illustrative embodiments, it should be understood that many other modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the principles disclosed herein. More specifically, various variations and modifications can be made to the components and / or layout of the subject matter combination within the scope of this disclosure. Besides variations and modifications to the components and / or layout, other uses will be apparent to those skilled in the art.

Claims

1. A local path decision-making and control method, characterized in that, Includes the following steps: Determine the vehicle's current position and heading, and its local path. Based on the vehicle's current location, point C, the subsequent path is planned into a fast segment, a slow segment, an acceleration segment, a deceleration segment, and a precise control segment, and the vehicle's throttle and / or speed are controlled according to the path plan. The process of planning the subsequent path into fast segment, slow segment, acceleration segment, deceleration segment and precise control segment, and controlling the vehicle's throttle and / or speed according to the path planning, specifically includes the following steps; The rice transplanting trajectory in the paddy field is planned as a combination of a straight path and a turning path; The straight path is divided into fast section, slow section, acceleration section, and deceleration section, and the vehicle is controlled according to the set road sections. The remaining path is planned as a precise control segment, slowing down the vehicle when it approaches the U-turn path and accelerating it when it moves away from the U-turn path; The precise control segment speed control method is as follows: Detect the distance dis_P_SP from the nearest start or end point of a turn to point P. The nearest start or end point of a turn to point P is the end point; point P is the projection point of point C onto the nearest rice planting path. When the distance dis_P_SP is less than the threshold, the following throttle control is enabled: ； throttle command throttle control command; k is a control parameter; para_throttle_min is the controllable minimum throttle, which is greater than the idle throttle; para_throttle_norm is the normal throttle setting.

2. The local path decision control method as described in claim 1, characterized in that, The determination of the vehicle's current position and heading along the local path specifically includes the following steps: The rice transplanting trajectory in the paddy field is planned as a combination of a straight path and a turning path; Calculate the projection point P from point C onto the nearest rice planting path, i.e., the projection. Calculate the vector from point C to the center point ou of the U-turn path. ( ): ； In the formula, Δx c The distance in the X direction from point C to point ou; x C Here is the X-coordinate of point C; x ou Let ou be the X-coordinate of point ou. In the formula, Δy c The distance in the Y direction from point C to point ou; y C Here is the Y-coordinate of point C; y ou Let ou be the Y-coordinate of point ou. Normalization yields vectors ( ): ； In the formula, Δx p The distance in the X direction from point P to point ou; Δy p The distance in the Y direction from point P to point ou; distance ouC The distance from point Ou to point C; w represents the width of the rice transplanter; ； In the formula, x p Let P be the X-coordinate of point P; y p Let P be the Y-coordinate of point P; Calculate vectors and cross product vector U2 ; ； In the formula, U2 is a point on the semicircular arc; U2 to the start of the turn U Start ; For U2 to the end of the turn U End ; Calculate vectors and cross product vector p ; ； In the formula, From point P to the starting point of the turn U Start ; From point P to the end of the turn U End ; when and When the license plate number is the same, the vehicle is on a U-turn route; when and When the license plate number is different, the vehicle is on a straight path.

3. The local path decision control method as described in claim 1, characterized in that, It also includes the following steps: The rice transplanting trajectory in the paddy field is planned as a combination of a straight path and a turning path; Plan the lifting point and landing point of the seedling carrier platform in the straight path, and control the lifting of the seedling carrier platform at the lifting point and control the landing of the seedling carrier platform at the landing point.

4. The local path decision control method as described in claim 3, characterized in that, The planned seedling platform lifting point and seedling platform landing point specifically include one of the following schemes; Option 1: When the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is greater than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, the situation is state 0. When in state 0, the lifting point of the seedling platform is the last intersection of the seedling claw of the seedling platform with the working boundary, and the landing point of the seedling platform is the intersection of the seedling platform and the exit point of the turning path. When the distance from the intersection of the rice planting operation boundary and the straight path before turning around to the turning path is less than the distance from the intersection of the rice planting operation boundary and the straight path after turning around to the turning path, this situation is state 1. In state 1, the lifting point of the seedling platform is the intersection of the seedling platform and the turning point of the turning path, and the landing point of the seedling platform is the initial intersection of the seedling claw of the seedling platform and the working boundary. Option 2: Calculate the starting point of the straight part of the J-shaped local path where each straight path and U-turn path are joined. Set the fixed distance outside the starting point of the straight part as the landing point of the pre-loaded seedling platform. The working range of the seedling platform from the landing point of the pre-loaded seedling platform to the end point of the straight part is the working range of the seedling platform in the current working row. Option 3: The seedling claws are controlled in real time; Option 4: Define the advance closing distance parameter for the seedling claw. Each seedling claw is located outside the seedling claw closing point, and the seedling claw closing operation is performed at the distance specified by the advance closing distance parameter. Option 5: Switch between manual and automatic modes. When in automatic mode, use any one of the above schemes from one to four for control. When operated manually, it is controlled by a person.

5. A local path decision control method as described in any one of claims 1-4, characterized in that, Lateral control of vehicle movement is implemented to prevent the vehicle from deviating laterally from its path.

6. A local path decision control method as described in any one of claims 1-4, characterized in that, When the first row is brought online or the operation is interrupted and the i-th row is brought online again, a local addition path is planned; i is the number of the interrupted row. The local addition path is a straight line segment from a point a certain distance outside the starting point of the straight line operation row to the starting point of that row. The planned partial inclusion path specifically includes the following steps: The search vehicle was determined to be on the rice planting path; If the path is determined to be a rice planting path, then the trajectory of that rice planting path will be executed. If the rice planting path is not determined, the nearest local entry path for the vehicle is calculated, and the vehicle enters the rice planting path trajectory through the local entry path.

7. The local path decision control method as described in claim 6, characterized in that, If the location is within the rice planting path, the trajectory of that rice planting path will be executed, specifically including the following steps: The rice transplanting trajectory in the paddy field is planned as a combination of a straight path and a turning path; If the vehicle is determined to be on a straight path within the rice planting route, continue executing the straight path directly. If the vehicle is determined to be on a U-turn path from the rice planting route, the current U-turn path number is obtained, and the current U-turn path is tracked.

8. A rice transplanter control system, executing the local path decision control method as described in any one of claims 1-7, characterized in that, include; A positioning module, which is used to locate the current position and heading of the rice transplanter; The planning module is used to obtain the planned path of the plot, determine the local path where the vehicle is currently located and heading, and plan the subsequent path into fast segment, slow segment, acceleration segment, deceleration segment and precise control segment; A control module is used to control the vehicle's movement according to a planned path and direction.

9. A rice transplanter, characterized in that, Including the rice transplanter control system as described in claim 8.

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