Control method of workshop feeding and discharging transport trolley

Abstract

The invention provides a control method of a workshop feeding and discharging transport trolley, which comprises a machine body, a lifting device, a chassis and a driving device, a containing groove is formed in the front side of the machine body, the lifting device comprises a fixed plate, a fixed block I and a fixed block II, and the fixed plate is fixedly arranged in the containing groove; the first fixing block is fixed to the fixing plate, the first fixing block and the second fixing block are located on the same vertical line, the driving device is fixedly connected with the first fixing block through a connecting block, and the end, connected with the first fixing block, of the driving device penetrates through the first fixing block to be fixedly connected with the second fixing block. The driving device drives the lifting device to slide up and down in the containing groove along the sliding rail in the height direction of the containing groove, driving wheels, driven wheels and universal wheels are arranged on the chassis, the fork arm penetrates through the bottom of the skip car, the skip car slides into the limiting groove, and therefore the skip car can be stably parked on the lifting device. And then the skip car is carried to the preset material frame according to the preset route through the conveying trolley, and carrying of the skip car at different heights is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of transport robots, and in particular to a control method for a workshop loading and unloading transport trolley. Background Art

[0002] The existing automatic guided transport vehicle is an industrial vehicle that loads goods automatically or manually, automatically drives along a set route or tows a cargo trolley to a designated location, and then automatically or manually loads and unloads goods.

[0003] For example, the patent document with Chinese patent application number 202221545193.5, publication date 2022.10.25, and classification number B25H5 / 00 discloses a material lifting vehicle, including a spring, a steering wheel, a pulley, a steel wire, a storage rod frame, a screw and a frame. A steering wheel is provided at the bottom of the frame, and a storage rod frame is slidably provided on the frame. The storage rod frame is connected to the upper end of the spring by a screw, and the lower end of the spring is connected to the bottom of the frame. A pulley is provided at the top of the frame, and the pull rod and the storage rod frame are connected by a steel wire.

[0004] The above document adopts a pulley group spring lifting trolley, uses the elastic force of the spring to keep the material in the appropriate position, and uses a pull rope to utilize the pulley group to achieve the coordination of the spring torque and the material lifting height, so as to ensure that the material picking position is always in the best position in actual production, reduce the workers' handling, and reduce the workers' labor intensity; however, the lifting height of the material lifting trolley in the above document is limited. In the actual operation process of the production workshop, it is necessary to transport the material trolley to material racks at different heights to realize material handling or unloading at different heights. The above document only describes the lifting trolley, and does not specifically describe how to transport the material trolley used to load materials to a preset position and lift the material trolley to different heights, so that the material trolley can be transported to material racks at different heights, and it is also impossible to ensure that the material trolley can reliably avoid on the planned local path. Summary of the invention

[0005] The purpose of the present invention is to provide a control method for a workshop loading and unloading material transport trolley, which can avoid the interference of other paths by planning a local path in the global path, and then accurately transport the material trolley to a preset position, thereby lifting the material trolley to material racks at different heights to realize material handling or unloading on the material trolley.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present invention is: a control method of a workshop loading and unloading transport trolley, comprising a transport trolley, the transport trolley comprising a body, a lifting device, a chassis and a driving device, the front side of the body is provided with a receiving groove, the lifting device comprises a fixed plate, a fixed block 1 and a fixed block 2, the fixed plate is fixedly arranged in the receiving groove, the fixed block 1 is fixed on the fixed plate and the fixed block 1 and the fixed block 2 are on the same vertical line, the driving device is connected with the fixed block 1 through a connecting block, and slide rails are respectively provided on both sides of the fixed block 1, one end of the driving device connected with the fixed block 1 passes through the fixed block 1 and is connected with the fixed block 2, the driving device drives the lifting device to slide up and down along the slide rail in the receiving groove along the height direction of the receiving groove, and the chassis is provided with a driving wheel, a driven wheel and a universal wheel; The control method further comprises the following steps: S1 controls the driving motor 1 through the control module to drive the driving wheel to rotate, so that the transport trolley comes to the rear side of the material vehicle according to the preset route, then adjusts the direction of the transport trolley, and then controls the driving motor 1 through the control module to drive the driving wheel to rotate, so that the length of the material vehicle falls within the range of the two rack arms; S2 makes the fork arm pass through the bottom of the material cart, and then makes the cross bar at the bottom of the material cart slide into the limit groove. After the material cart is parked on the fork arm, the control module controls the drive motor 2 to drive the electric push rod to drive the lifting device to rise along the slide rail in the receiving groove. When the material cart is lifted off the ground, the drive motor 2 stops running; S3 generates a global path between the initial node and the target node in the preset route, then generates more than one local path on the global path, and evaluates the speed of different local paths through the speed evaluation function. The speed evaluation function is: Cost(v,w) =100 +[delta_cost(v,w)* a]+ [dis_angle(v,w)*β]+ [dis_angle(v,w)*traj.xv *γ]+[ (diff_delta / 2)* vel(v,w)*δ]+[ dis_goal(v,w)*η]; a is the preset steering wheel angle deviation constant of the forklift robot; β is the angle error constant of the forklift robot; γ is the deceleration constant; δ is the acceleration constant; η is the target following error constant; delta_cost(v,w) is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is the cost value of the deviation between the optimal steering angle of the vehicle body and the current steering angle of the vehicle body; traj.xv is the linear speed when tracing the path; diff_delta is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the steering wheel; dis_goal(v,w) is the target node evaluation function; vel(v,w) is the speed evaluation function; dis_goal(v,w) is the penalty cost value for exceeding the end point; S4 selects the local path with the lowest evaluation score as the optimal path, and then the transport trolley moves along the optimal path to approach the target node. After reaching the target node, the control module controls the drive motor 2 to continue to drive the electric push rod to drive the lifting device to rise. After rising to a preset height, the control module controls the drive motor 1 to drive the drive wheel to rotate and adjust the distance between the transport trolley and the material rack, so that the lifted material trolley is located above the material rack; S5 controls the drive motor 2 through the control module to drive the electric push rod to drive the lifting device to descend until the material cart is parked on the material rack. The lifting device continues to descend until the cross bar at the bottom of the material cart slides out of the limit groove and the fork arm is completely separated from the bottom of the material cart. The control module controls the drive motor 1 to drive the drive wheel to rotate to make the transport cart leave the material rack.

[0007] Furthermore, the receiving groove is arranged along the height direction of the body and the height of the receiving groove matches the height of the body; the bottom of the fixing plate contacts the bottom of the receiving groove, and there are gaps between the two sides of the fixing plate and the two sides of the receiving groove; and a control module is arranged in the body.

[0008] The above arrangement facilitates the lifting device to be arranged in the receiving groove of the machine body and to be able to move up and down in the receiving groove, and enables the lifting device to avoid collision with the bottom and both sides of the receiving groove during the movement of the lifting device in the receiving groove.

[0009] Furthermore, the driving device includes a driving motor 2 and an electric push rod device, the electric push rod device includes an electric push rod and an electric push rod box, one end of the driving motor 2 is arranged in the accommodating groove, the output end of the driving motor 2 is connected to one end of the electric push rod box, and the other end of the electric push rod box is connected to the connecting block.

[0010] The above arrangement can drive the electric push rod to telescopically move along the height direction of the machine body through the driving motor 2.

[0011] Furthermore, the fixing block one is provided with a slot one whose opening is arranged upward along the height direction of the body, and a through hole matching the electric push rod is provided at the bottom of the slot one. The fixing block two is arranged directly below the fixing block one, and the fixing block two is provided with a slot two whose opening is arranged downward along the height direction of the body, and a through hole matching the electric push rod is provided at the top of the slot two.

[0012] The above arrangement facilitates the electric push rod to pass through the through hole and connect with the second fixing block.

[0013] Furthermore, one end of the electric push rod is telescopically arranged in the electric push rod box, and the other end of the electric push rod passes through the through hole on the fixed block 2 and is connected to the fixed block 2 by screws. The length of the slide rail is greater than the telescopic stroke of the electric push rod.

[0014] The above arrangement enables the electric push rod to be fixedly connected to the fixing block 2 through screws, thereby driving the fixing block 2 to move up and down.

[0015] Furthermore, the lifting device also includes a connecting plate, one or more fork arms and a slider, the fork arm is arranged on the front side of the connecting plate, one end of the slider is fixed on the rear side of the connecting plate, the rear side of the connecting plate is connected to the second fixed block, the front side of the connecting plate is provided with a protruding accommodating groove, the other end of the slider is provided with a through groove matching the slide rail, and the slider is slidably connected to the slide rail through the through groove.

[0016] With the above arrangement, when the driving device drives the fixed block 2 to move up and down, it can drive the lifting device to move up and down synchronously through the sliding connection between the slider and the slide rail, and then drive the material cart on the fork arm to move up and down.

[0017] Furthermore, the spacing between the fork arms matches the width of the material cart, one end of the fork arm is fixed to the front side of the connecting plate, the other end of the fork arm is perpendicular to one end of the fork arm and extends outward along the front direction of the machine body, a limit groove is provided at the vertical position, and a limit block is provided in the limit groove near one end of the fork arm.

[0018] The above arrangement, through the dual functions of the limit groove and the limit block, after the cross bar at the bottom of the trolley slides into the limit groove, the limit block limits the longitudinal movement distance of the trolley in the limit groove, so that the trolley can stay stably on the fork arm.

[0019] Furthermore, the chassis includes a frame, a connecting frame, a steering device and a driving motor. Frame arms are respectively provided at both ends of the front side of the frame, one end of the frame arm is connected to the frame, and the other end of the frame arm is extended outward along the front direction of the frame. The driven wheel is arranged at the extended end of the frame arm, both sides of one end of the connecting frame are connected to the frame, and universal wheels are provided on both sides of the other end of the connecting frame, and one end of the connecting frame is connected to the steering device.

[0020] With the above arrangement, when the steering device rotates, the driving wheel can be driven to rotate in different directions.

[0021] Furthermore, the steering device includes a driving motor three, a driving gear, a driven gear, a bearing and a support plate. The driving motor three is fixed to the support plate through a motor fixing frame three. The support plate is provided with a through hole matching the output shaft end of the driving motor three. The output shaft end of the driving motor three is connected to the driving gear. The driving gear is externally meshed and rotatably connected to the driven gear sleeved on the bearing. The upper side of the driven gear protrudes upward to form an upper convex portion, and the lower side of the driven gear protrudes upward to form a lower convex portion. The upper convex portion is connected to one end of the connecting frame, the lower convex portion is connected to the top of the supporting plate, the bottom of the supporting plate is connected to one end of the connecting member, and the other end of the connecting member is provided with a through hole. The driving motor one is fixed to the other end of the connecting member through a motor fixing frame one, and the output shaft end of the driving motor one is connected to the driving wheel.

[0022] With the above arrangement, when the driving motor 1 drives the driving wheel to rotate, the driving motor 3 can also drive the driving gear to rotate, thereby driving the driven gear to rotate. Since the driven gear and the connecting member are connected to form an integral whole through the supporting plate, and the driving wheel is arranged on the connecting member, the driving wheel can be driven to rotate in different directions, thereby enabling the chassis to achieve steering during walking.

[0023] Furthermore, in step S3, delta_cost(v,w) is calculated by the following formula: delta_cost(v,w)=θ bw -θ t , θ bw =arctan[(2θ p -θ t ) / (θ pr -θ r )], θ bw is the optimal steering angle of the steering wheel; θ p is the angle of entering the next node p on the local path; θ t is the body navigation angle of the forklift robot at time t; θ r is the current navigation angle of the forklift robot; θ pr is the angle between the next node p in the local path and the current coordinates of the forklift robot; the average value of delta_cost(v,w) at different times is taken as the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is calculated by the following formula: dis_angle(v,w)=|θ p -θ t|, θ p =arctan[(y p -y t ) / (x p -x t )], y p is the y coordinate of the next node p; t is the y coordinate of the forklift robot at time t; x p is the x coordinate of the next node p; t is the x-coordinate of the forklift robot at time t; the average value of dis_angle(v,w) at different times is taken as the cost value of the deviation between the optimal orientation angle of the vehicle body and the current orientation angle of the vehicle body; diff_delta is calculated by the following formula: diff_delta=θ bw -θ w； θ w is the current steering wheel heading angle; In the above method, by calculating the average value, the cost value of the deviation between the optimal steering wheel orientation angle and the current orientation angle of the vehicle body is highly accurate; by calculating the average value, the cost value of the deviation between the optimal orientation angle of the vehicle body and the current orientation angle of the vehicle body is highly accurate.

[0024] Furthermore, the step S4 also includes: S4.1 determines whether the node with the shortest distance to the forklift robot on the global path is the target node when the forklift robot is at the end node of the local path; if not, dis_goal(v, w) is 0; if so, dis_goal(v, w)=L*cosθ L ; L is the distance between the local path end node and the target node; θ L It is the angle between the line connecting the local path end node and the target node relative to the direction of the preferred path straight line.

[0025] In the above method, when the local path end node is inconsistent with the target node, it means that the target node is located in front of the local path end node, and it does not interfere with the movement of the transport vehicle to the local path end node; when the local path end node is consistent with the target node, if the transport vehicle moves in front of the local path end node, it will cause the transport vehicle to exceed the target node, thus passing L and θ L Calculate the distance that the transport vehicle exceeds the target node so that the transport vehicle can return to the target node accurately.

[0026] The beneficial effects of the present invention are as follows: by setting the fixing block 1 on the fixing plate and making the fixing block 1 and the fixing block 2 on the same vertical line, the fixing block 1 can be connected to the lifting device through the driving device; and slide rails are set on the fixing plate and on both sides of the fixing block 1, so that the lifting device can be driven by the driving device to slide up and down in the receiving groove along the slide rails; in addition, by setting the length of the material cart to fall within the range of the two frame arms, it is convenient for the fork arm to pass through the bottom of the material cart, and at the same time, the cross bar at the bottom of the material cart slides into the limiting groove, so that the material cart can be stably parked on the fork arm; then By selecting the local path closest to the global path as the optimal path, the trajectory of the optimal path is made to fit the trajectory of all paths, so that the optimal path has good smoothness, thereby avoiding interference with another global path when the transport trolley moves along the optimal path, and at the same time will not interfere with other transport trolleys moving between another different initial node and different target node, thereby accurately and stably transporting the material cart to the target position; then the control module controls the drive motor 2 to drive the electric push rod to drive the lifting device to achieve lifting, so that the material cart can be lifted to the material rack at a preset height to complete the transportation of the material cart. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of the structure of a material cart parked on the present invention.

[0028] Figure 2 It is a schematic diagram of the overall structure of the present invention.

[0029] Figure 3 It is a partial exploded view of the lifting device in the present invention.

[0030] Figure 4 It is a partial exploded view of the chassis structure in the present invention.

[0031] Figure 5 It is a partial cross-sectional view in the present invention.

[0032] Figure 6 This is a schematic diagram of the transport vehicle approaching the next node of the local path in the present invention.

[0033] Figure 7 It is a schematic diagram of the transport vehicle approaching the target node in the present invention.

[0034] Figure Number: 01. Material cart, 1. Machine body, 11. Receiving slot, 12. Connecting piece, 20. Fixed plate, 21. Fixed block 1, 22. Fixed block 2, 23. Connecting plate, 24. Fork arm, 25. Slider, 26. Limiting slot, 27. Limiting block, 211. Slot 1, 212. Slot 2, 3. Connecting block, 31. Driving gear, 32. Driven gear; 33. Driving motor 3, 34. Bearing, 35. Support plate, 321. Upper convex part, 333. Motor fixing frame 3, 41. Slide rail, 52. Driving motor 2, 53. Electric push rod, 54. Electric push rod box, 6. Rack, 61. Rack arm, 7. Connecting frame, 8. Driving motor 1, 81. Motor fixing frame 1, 9. Driven wheel, 10. Universal wheel, 101. Driving wheel, a1. Global path, a2. Local path, a11. Target node. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figures 1 to 7 As shown, a workshop loading and unloading transport trolley includes a body 1, a lifting device, a chassis and a driving device. The front side of the body 1 is provided with a receiving groove 11. In this embodiment, the receiving groove 11 is arranged along the height direction of the body 1 and the height of the receiving groove 11 matches the height of the body 1. The lifting device includes a fixing plate 20, a fixing block 1 21 and a fixing block 22. The fixing plate 20 is fixed in the receiving groove 11 by bolts. In this embodiment, the bottom of the fixing plate 20 contacts the bottom of the receiving groove 11, and the two sides of the fixing plate 20 are spaced from the two sides of the receiving groove 11. The fixing block 1 21 is fixed to the fixing plate 20 by bolts. The fixed block 1 21 and the fixed block 22 are on the same vertical line and the fixed block 22 is arranged directly below the fixed block 1 21. The driving device is connected to the fixed block 1 21 through the connecting block 3. Two symmetrically arranged slide rails 41 are arranged on both sides of the fixed block 1 21. The end of the driving device connected to the fixed block 1 21 passes through the fixed block 1 21 and is connected to the fixed block 2 22. The driving device drives the lifting device to slide up and down along the slide rail 41 in the receiving groove 11 along the height direction of the receiving groove 11. In this embodiment, a control module (not marked in the figure) is provided in the body 1 for controlling the operation of the transport trolley. This is a prior art and will not be repeated here.

[0037] like Figure 2 , 3As shown, the driving device includes a driving motor 52 and an electric push rod device, the electric push rod device includes an electric push rod 53 and an electric push rod box 54, one end of the driving motor 52 is fixed on the body 1 located in the accommodating groove 11, the output end of the driving motor 52 is connected to one end of the electric push rod box 54, the other end of the electric push rod box 54 is connected to the connecting block 3, one end of the electric push rod 53 is telescopically arranged in the electric push rod box 54, the other end of the electric push rod 53 passes through a through hole (not marked in the figure) on the fixed block 22 and is connected to the fixed block 22 by screws, so that the electric push rod 53 can be connected to the fixed block 22 by screws, and then the fixed block 22 can be driven to move up and down.

[0038] like Figure 3 As shown, the fixing block 1 21 is provided with a slot 1 211 with an opening arranged upward along the height direction of the body 1, and a through hole matching the electric push rod 53 is provided at the bottom of the slot 1 211. The fixing block 22 is arranged directly below the fixing block 1 21. The fixing block 22 is provided with a slot 212 with an opening arranged downward along the height direction of the body 1, and a through hole matching the electric push rod 53 is provided at the top of the slot 212. The above arrangement facilitates the electric push rod 53 to pass through the through hole and connect with the fixing block 22.

[0039] like Figure 2 , Figure 3 As shown, the lifting device also includes a connecting plate 23, one or more fork arms 24 and a slider 25. The fork arms 24 are arranged on the front side of the connecting plate 23. In the present embodiment, the fork arms 24 are arranged in two numbers, and the sliders 25 are arranged in four numbers. One end of the slider 25 is fixed to the rear side of the connecting plate 23, and the rear side of the connecting plate 23 is connected to one side of the fixed block 22. The front side of the connecting plate 23 is provided with a protruding receiving groove 22, and the other end of the slider 25 is provided with a through groove (not marked in the figure) matching the slide rail 41. The slider 25 is slidably connected to the slide rail 41 through the through groove. In this way, when the driving device drives the fixed block 22 to move up and down, the lifting device can be driven to move up and down synchronously through the sliding connection between the slider 25 and the slide rail 41, and then the material cart 01 on the fork arm 24 can be driven to move up and down; in the present embodiment, the length of the slide rail 41 is greater than the telescopic stroke of the electric push rod 53, so that the lifting device can be prevented from being separated from the slide rail 41 during the process of the driving device driving the lifting device to move up and down along the slide rail 41.

[0040] like Figure 2 , Figure 5As shown, the spacing between the fork arms 24 matches the width of the material cart 01, one end of the fork arm 24 is fixed to the front side of the connecting plate 23, the other end of the fork arm 24 is perpendicular to one end of the fork arm 24 and extends outward along the front of the body 1, and a limit groove 26 is provided at the vertical position, and a limit block 27 is provided in the limit groove 26 near one end of the fork arm 24. In this embodiment, one end of the limit block 27 is arranged in the limit groove 26 and matches one end of the limit groove 26, and the other end of the limit block 27 extends outward of the limit groove 26 along the height direction of the fork arm 24, and the limit block 27 is fixed to one end of the fork arm 24 by bolts. Through the dual action of the limit groove 26 and the limit block 27, after the cross bar at the bottom of the material cart 01 slides into the limit groove 26, the limit block 27 limits the moving distance of the material cart 01 in the longitudinal direction in the limit groove 26, so that the material cart 01 can stay stably on the fork arm 24.

[0041] like Figure 3 and Figure 4 As shown, the chassis includes a frame 6, a connecting frame 7, a steering device and a driving motor 8. Frame arms 61 are respectively provided at both ends of the front side of the frame 6. One end of the frame arm 61 is connected to the frame 6, and the other end of the frame arm 61 is extended outward along the front direction of the frame 6. The driven wheel 9 is arranged at the extended end of the frame arm 61. Both sides of one end of the connecting frame 7 are connected to the frame 6. Both sides of the other end of the connecting frame 7 are provided with universal wheels 10. The steering device includes a driving motor 33, a driving gear 31, a driven gear 32, a bearing 34 and a supporting plate 35. The driving motor 33 is fixed to the supporting plate 35 through a motor fixing frame 333. The supporting plate 35 is provided with a through hole (not marked in the figure) matching the output shaft end of the driving motor 33. The output shaft end of the driving motor 33 is fixedly connected to the driving gear 31. The driving gear 31 is externally meshed and rotatably connected with the driven gear 32 sleeved on the bearing 34. The upper side of the connecting frame 7 protrudes upward to form an upper protrusion 321, and the lower side of the driven gear 32 protrudes upward to form a lower protrusion (not marked in the figure). The upper protrusion 321 is connected to the bottom of the connecting frame 7, and the lower protrusion is connected to the top of the support plate 35. The bottom of the support plate 35 is connected to one end of the connecting member 12, and the other end of the connecting member 12 is provided with a through hole (not marked in the figure). The driving motor 8 is fixed to the other end of the connecting member 12 through a motor fixing frame 81, and the output shaft end of the driving motor 8 is connected to the driving wheel 101. In this way, when the driving motor 8 drives the driving wheel 101 to rotate, the driving motor 33 can also drive the driving gear 31 to rotate, thereby driving the driven gear 32 to rotate. Since the driven gear 32 and the connecting member 12 are connected to form a whole through the supporting plate 35, and the driving wheel 101 is arranged on the connecting member 12, it can drive the driving wheel 101 to rotate in different directions, thereby enabling the chassis to achieve steering during walking.

[0042] like Figure 6As shown, in this embodiment, a control method for a workshop transport trolley includes the following specific steps: The S1 control module controls the drive motor 8 to drive the drive wheel 101 to rotate, so that the transport trolley comes to the rear side of the material cart 01 according to the preset route, and then adjusts the direction of the transport trolley. Then the control module controls the drive motor 8 to drive the drive wheel 101 to rotate, so that the length of the material cart 01 falls within the range of the two frame arms 61.

[0043] S2 makes the fork arm 24 pass through the bottom of the trolley 01, and then makes the cross bar at the bottom of the trolley 01 slide into the limit groove 26. After the trolley 01 is parked on the fork arm 24, the control module controls the drive motor 2 52 to drive the electric push rod 53 to drive the lifting device to rise along the slide rail 41 in the receiving groove 11. When the trolley 01 is lifted off the ground, the drive motor 2 52 stops running.

[0044] S3 generates a global path a1 between the initial node and the target node in the preset route, then generates more than one local path a2 on the global path a1, and evaluates the speed of different local paths a2 by the speed evaluation function. The speed evaluation function is: Cost(v,w) =100 +[delta_cost(v,w)* a]+ [dis_angle(v,w)*β]+ [dis_angle(v,w)*traj.xv *γ]+[ (diff_delta / 2)* vel(v,w)*δ]+[ dis_goal(v,w)*η]; a is the preset steering wheel angle deviation constant of the forklift robot; β is the angle error constant of the forklift robot; γ is the deceleration constant; δ is the acceleration constant; η is the target following error constant; delta_cost(v,w) is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is the cost value of the deviation between the optimal steering angle of the vehicle body and the current steering angle of the vehicle body; traj.xv is the linear speed when tracing the path; diff_delta is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the steering wheel; dis_goal(v,w) is the target node evaluation function; vel(v,w) is the speed evaluation function; dis_goal(v,w) is the penalty cost value for exceeding the end point; delta_cost(v,w) is calculated by the following formula: delta_cost(v,w)=θ bw -θ t , θ bw =arctan[(2θ p -θ t) / (θ pr -θ r )], θ bw is the optimal steering angle of the steering wheel; θ p is the angle of entering the next node p of the local path; θ t is the body navigation angle of the forklift robot at time t; θ r is the current navigation angle of the forklift robot; θ pr is the angle between the next node p in the local path and the current coordinates of the forklift robot; the average value of delta_cost(v,w) at different times is taken as the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is calculated by the following formula: dis_angle(v,w)=|θ p -θ t |, θ p =arctan[(y p -y t ) / (x p -x t )], y p is the y coordinate of the next node p; t is the y coordinate of the forklift robot at time t; x p is the x coordinate of the next node p; t is the x-coordinate of the forklift robot at time t; the average value of dis_angle(v,w) at different times is taken as the cost value of the deviation between the optimal orientation angle of the vehicle body and the current orientation angle of the vehicle body; diff_delta is calculated by the following formula: diff_delta=θ bw -θ w； θ w is the current steering wheel heading angle; Step S3 also includes presetting the moving speed range, maximum acceleration and maximum deceleration speed of the transport vehicle.

[0045] Moving speed range v1={(v,w) | v∈[v min ,v max ],w∈[w min ,w max ]}. The maximum speed range and minimum speed range of the transport trolley are preset; they can be adjusted according to different usage scenarios to meet different usage requirements.

[0046] Maximum acceleration

[0047] v c is the current linear speed of the transport vehicle, w c is the current angular velocity of the transport vehicle; is the maximum linear speed of the transport trolley; is the minimum linear speed of the transport trolley; is the maximum angular velocity of the transport trolley; is the maximum angular velocity of the transport vehicle.

[0048] Maximum deceleration dist(v,w) is the shortest distance between the transport vehicle and the obstacle.

[0049] S4 selects the local path with the lowest evaluation score as the optimal path, and then the transport trolley moves along the optimal path to approach the target node. After reaching the target node, the control module controls the drive motor 2 52 to continue to drive the electric push rod 53 to drive the lifting device to rise. After rising to a preset height, the control module controls the drive motor 1 8 to drive the drive wheel 101 to rotate and adjust the distance between the transport trolley and the material rack 01, so that the lifted material trolley 01 is located above the material rack; Step S4 also includes: When S4.1 moves along the optimal path and approaches the target node, it is determined whether the node with the shortest distance to the transport vehicle on the global path a1 is the target node a11 when the transport vehicle is at the local path end node K; if not, dis_goal(v, ω) is 0; if so, dis_goal(v, ω)=L*cosθ L ; L is the distance between the local path end node K and the target node a11; θ L is the angle between the line connecting the local path end node and the target node relative to the direction of the preferred path straight line. When the local path end node is inconsistent with the target node, it means that the target node is located in front of the local path end node, and it does not interfere with the movement of the transport vehicle to the local path end node; when the local path end node is consistent with the target node, if the transport vehicle moves in front of the local path end node, it will cause the transport vehicle to exceed the target node, thus passing L and θ L The distance LA that the transport vehicle exceeds the target node is calculated so that the transport vehicle can accurately return to the target node.

[0050] S5 The control module controls the drive motor 2 52 to drive the electric push rod 53 to drive the lifting device to descend until the trolley 01 is parked on the material rack. The lifting device continues to descend until the cross bar at the bottom of the trolley 01 slides out of the limit groove 36 and the fork arm 24 is completely separated from the bottom of the trolley 01. The control module controls the drive motor 1 8 to drive the drive wheel 101 to rotate to make the transport trolley leave the material rack.

Claims

1. A control method for a workshop loading and unloading transport vehicle, comprising a body, a lifting device, a chassis and a driving device, characterized in that: The front side of the machine body is provided with a receiving groove, the lifting device comprises a fixing plate, a fixing block 1 and a fixing block 2, the fixing plate is fixedly arranged in the receiving groove, the fixing block 1 is fixed on the fixing plate and the fixing block 1 and the fixing block 2 are on the same vertical line, the driving device is fixedly connected with the fixing block 1 through a connecting block, and slide rails are respectively provided on both sides of the fixing block 1, one end of the driving device connected with the fixing block 1 passes through the fixing block 1 and is fixedly connected with the fixing block 2, the driving device drives the lifting device to slide up and down along the slide rail in the receiving groove along the height direction of the receiving groove, and the chassis is provided with a driving wheel, a driven wheel and a universal wheel; The control method further comprises the following steps: S1 controls the driving motor 1 through the control module to drive the driving wheel to rotate, so that the transport trolley comes to the rear side of the material vehicle according to the preset route, then adjusts the direction of the transport trolley, and then controls the driving motor 1 through the control module to drive the driving wheel to rotate, so that the length of the material vehicle falls within the range of the two rack arms; S2 makes the fork arm pass through the bottom of the material cart, and then makes the cross bar at the bottom of the material cart slide into the limit groove. After the material cart is parked on the fork arm, the control module controls the drive motor 2 to drive the electric push rod to drive the lifting device to rise along the slide rail in the receiving groove. When the material cart is lifted off the ground, the drive motor 2 stops running; S3 generates a global path between the initial node and the target node in the preset route, then generates more than one local path on the global path, and evaluates the speed of different local paths through the speed evaluation function. The speed evaluation function is: Cost(v,w) =100 +[delta_cost(v,w)* a]+ [dis_angle(v,w)*β]+ [dis_angle(v,w)*traj.xv *γ]+[ (diff_delta / 2)* vel(v,w)*δ]+[ dis_goal(v,w)*η]; a is the preset steering wheel angle deviation constant of the forklift robot; β is the angle error constant of the forklift robot; γ is the deceleration constant; δ is the acceleration constant; η is the target following error constant; delta_cost(v,w) is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is the cost value of the deviation between the optimal steering angle of the vehicle body and the current steering angle of the vehicle body; traj.xv is the linear speed when tracing the path; diff_delta is the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the steering wheel; dis_goal(v,w) is the target node evaluation function; vel(v,w) is the speed evaluation function; dis_goal(v,w) is the penalty cost value for exceeding the end point; S4 selects the local path with the lowest evaluation score as the optimal path, and then the transport trolley moves along the optimal path to approach the target node. After reaching the target node, the control module controls the drive motor 2 to continue to drive the electric push rod to drive the lifting device to rise. After rising to a preset height, the control module controls the drive motor 1 to drive the drive wheel to rotate and adjust the distance between the transport trolley and the material rack, so that the lifted material trolley is located above the material rack; S5 controls the drive motor 2 through the control module to drive the electric push rod to drive the lifting device to descend until the material cart is parked on the material rack. The lifting device continues to descend until the cross bar at the bottom of the material cart slides out of the limit groove and the fork arm is completely separated from the bottom of the material cart. The control module controls the drive motor 1 to drive the drive wheel to rotate to make the transport cart leave the material rack.

2. The control method of a workshop loading and unloading transport vehicle according to claim 1 is characterized in that: The receiving groove is arranged along the height direction of the machine body and the height of the receiving groove matches the height of the machine body; the bottom of the fixing plate contacts the bottom of the receiving groove, and there are intervals between the two sides of the fixing plate and the two sides of the receiving groove; a control module is arranged in the machine body.

3. The control method of a workshop loading and unloading transport vehicle according to claim 1 is characterized in that: The driving device includes a second driving motor and an electric push rod device, the electric push rod device includes an electric push rod and an electric push rod box, one end of the second driving motor is arranged in the accommodating groove, the output end of the second driving motor is connected to one end of the electric push rod box, and the other end of the electric push rod box is connected to the connecting block.

4. The control method of a workshop loading and unloading transport vehicle according to claim 1 is characterized in that: The fixing block 1 is provided with a slot 1 which opens upward along the height direction of the machine body, and a through hole matching the electric push rod is provided at the bottom of the slot 1. The fixing block 2 is arranged directly below the fixing block 1, and the fixing block 2 is provided with a slot 2 which opens downward along the height direction of the machine body, and a through hole matching the electric push rod is provided at the top of the slot 2.

5. The control method of a workshop loading and unloading transport vehicle according to claim 4 is characterized in that: One end of the electric push rod is telescopically arranged in the electric push rod box, and the other end of the electric push rod passes through the through hole on the fixed block 2 and is fixedly connected to the fixed block 2 by screws. The length of the slide rail is greater than the telescopic stroke of the electric push rod.

6. The control method of a workshop loading and unloading transport vehicle according to claim 1 is characterized in that: The lifting device also includes a connecting plate, one or more fork arms and a slider, the fork arm is arranged on the front side of the connecting plate, one end of the slider is fixed to the rear side of the connecting plate, the rear side of the connecting plate is fixedly connected to the second fixing block, the front side of the connecting plate is provided with a protruding accommodating groove, the other end of the slider is provided with a through groove matching the slide rail, and the slider is slidably connected to the slide rail through the through groove.

7. The control method of a workshop loading and unloading transport vehicle according to claim 6 is characterized in that: The spacing between the fork arms matches the width of the material car, one end of the fork arm is fixed to the front side of the connecting plate, the other end of the fork arm is perpendicular to one end of the fork arm and extends outward along the front of the machine body, a limit groove is provided at the vertical position, and a limit block is provided in the limit groove near one end of the fork arm.

8. The control method of a workshop loading and unloading transport vehicle according to claim 1 is characterized in that: The chassis includes a frame, a connecting frame, a steering device and a driving motor. Frame arms are respectively provided at both ends of the front side of the frame, one end of the frame arm is fixedly connected to the frame, and the other end of the frame arm is extended outward along the front direction of the frame. The driven wheel is arranged at the extended end of the frame arm, both sides of one end of the connecting frame are fixedly connected to the frame, and universal wheels are provided on both sides of the other end of the connecting frame. One end of the connecting frame is fixedly connected to the steering device.

9. A control method for a workshop loading and unloading transport vehicle according to claim 8, characterized in that: The steering device includes a driving motor three, a driving gear, a driven gear, a bearing and a supporting plate. The driving motor three is fixed to the supporting plate through a motor fixing frame three. The supporting plate is provided with a through hole matching the output shaft end of the driving motor three. The output shaft end of the driving motor three is rotatably connected to the driving gear. The driving gear is externally meshed and rotatably connected to the driven gear sleeved on the bearing. The upper side of the driven gear protrudes upward to form an upper convex portion, and the lower side of the driven gear protrudes upward to form a lower convex portion. The upper convex portion is fixedly connected to one end of the connecting frame, and the lower convex portion is fixedly connected to the top of the supporting plate. The bottom of the supporting plate is fixedly connected to one end of the connecting member, and the other end of the connecting member is provided with a through hole. The driving motor one is fixed to the other end of the connecting member through a motor fixing frame one, and the output shaft end of the driving motor one is rotatably connected to the driving wheel.

10. The control method of a workshop loading and unloading transport vehicle according to claim 1, characterized in that: The following steps are involved: In step S3, delta_cost(v,w) is calculated by the following formula: delta_cost(v,w)=θ bw -θ t , i bw =arctan[(2θ p -θ t ) / (θ pr -θ r )], θ bw is the best heading angle of the steering wheel; θ p is the angle of entering the next node p on the local path; θ t is the body navigation angle of the forklift robot at time t; θ r is the current navigation angle of the forklift robot; θ pr is the angle between the next node p in the local path and the current coordinates of the forklift robot; the average value of delta_cost(v,w) at different times is taken as the cost value of the deviation between the optimal steering angle of the steering wheel and the current steering angle of the vehicle body; dis_angle(v,w) is calculated by the following formula: dis_angle(v,w)=|θ p -θ t |, θ p =arctan[(and p -and t ) / (x p -x t )] , y p is the y coordinate of the next node p; t is the y coordinate of the forklift robot at time t; x p is the x coordinate of the next node p; t is the x-coordinate of the forklift robot at time t; the average value of dis_angle(v,w) at different times is taken as the cost value of the deviation between the optimal orientation angle of the vehicle body and the current orientation angle of the vehicle body; diff_delta is calculated by the following formula: diff_delta=θ bw -θ w； θ w is the current steering wheel heading angle; The step S4 also includes: S4.1 determines whether the node with the shortest distance to the forklift robot on the global path is the target node when the forklift robot is at the end node of the local path; if not, dis_goal(v, w) is 0; if so, dis_goal(v, w)=L*cosθ L ; L is the distance between the local path end node and the target node; θ L It is the angle between the line connecting the local path end node and the target node relative to the direction of the preferred path straight line.

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