Method, system, equipment, medium and program product for safe operation of unmanned forklift

Abstract

The present application provides a method, system, device, medium and program product for the safe operation of an unmanned forklift, and relates to the technical field of unmanned forklifts. The method includes: after the unmanned forklift receives an instruction, when the fork is in a safe state, the unmanned forklift inserts the cargo at the first target position based on the trigger state of the sensor and the detection data of the fork strain; plans the operation path of the unmanned forklift; controls the operation of the unmanned forklift based on the operation path and the trigger state of the obstacle avoidance sensor and the edge switch; when the unmanned forklift runs to the second target position, the cargo is placed at the second target position based on the trigger state of the sensor and the detection data of the fork strain. The method, system, device, medium and program product for the safe operation of the unmanned forklift provided in the present application can ensure the safe operation of the unmanned forklift in outdoor loading and unloading scenarios. In particular, the proposed safe operation method based on fork strain detection can be applied to the safe insertion and placement of cargo when the cargo is not placed in a standardized manner.

Description

Technical Field

[0001] The present application relates to the technical field of unmanned forklifts, and in particular to a method, system, equipment, medium and program product for the safe operation of an unmanned forklift. Background Art

[0002] The safety design of unmanned forklifts is a comprehensive consideration process, which aims to ensure that the forklifts can operate safely, stably and efficiently in an automated operating environment.

[0003] At present, unmanned operations in the logistics and warehousing field have become mature, but outdoor unmanned loading and unloading technology has always been a technical problem in the logistics and warehousing industry. On the one hand, there is a lack of complete design methods and systems for outdoor unmanned forklifts. On the other hand, non-fixed cargo locations, non-fixed routes and complex outdoor interference environments have made traditional automated guided vehicles (AGV) equipment unable to meet the safe operation requirements of outdoor loading and unloading. Summary of the invention

[0004] The present application provides a method, system, device, medium and program product for the safe operation of an unmanned forklift, which is used to solve the defect in the prior art that traditional AGV unmanned forklifts are difficult to meet the safe operation requirements of outdoor loading and unloading.

[0005] In a first aspect, the present application provides a method for safe operation of an unmanned forklift, comprising:

[0006] After receiving the command of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is raised and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain;

[0007] Plan the operation path of the unmanned forklift carrying goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0008] Controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0009] When the unmanned forklift runs to the second target position, when the fork is raised and lowered to a safe state, the cargo is placed at the second target position based on the triggering states of multiple in-position sensors and the detection data of the fork strain.

[0010] Optionally, the safety state of the fork lifting and lowering is determined based on the upper and lower limit proximity switches and the laser rangefinder;

[0011] The method of inserting the cargo at the first target position based on the trigger status of the plurality of in-place sensors and the detection data of the fork strain comprises:

[0012] Determine the distance between the truck pallet and the edge of the unmanned forklift;

[0013] In the case where the distance is less than a preset threshold, when the triggering states of the multiple in-place sensors are all triggered, it is determined that the unmanned forklift safely inserts the cargo;

[0014] When the distance is greater than or equal to a preset threshold, based on the distance, the unmanned forklift is controlled to travel to a first parking position;

[0015] Lifting the fork of the unmanned forklift, and calibrating the torque based on the detection data of the strain of the fork;

[0016] Based on the torque, the unmanned forklift is controlled to pick up the cargo;

[0017] Control the unmanned forklift for picking up the goods to drive to the second docking position;

[0018] placing goods based on the detection data of the fork strain;

[0019] The goods are re-inserted based on the triggering status of the multiple in-place sensors.

[0020] Optionally, controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge switch includes:

[0021] When the unmanned forklift is traveling along the running path, judging whether there is an obstacle based on the triggering state of the obstacle avoidance sensor; and judging whether the unmanned forklift collides with the obstacle based on the triggering state of the edge contact switch;

[0022] When there are no obstacles and the unmanned forklift does not collide with the obstacles, control the unmanned forklift to continue running;

[0023] When there is an obstacle and the unmanned forklift collides with the obstacle, control the unmanned forklift to stop;

[0024] When there is an obstacle and the unmanned forklift does not collide with the obstacle, the operating state of the unmanned forklift is adjusted based on the size of the obstacle, the distance of the obstacle and the position of the unmanned forklift.

[0025] Optionally, the method further comprises:

[0026] Determining the operating state of the unmanned forklift when traveling along the operating path;

[0027] When the unmanned forklift is in a safe operating state, a first prompt tone is played and a light of a first attribute is displayed;

[0028] When the distance between the unmanned forklift and the obstacle is less than the preset distance, a second prompt sound is played and a light of a second attribute is displayed;

[0029] When the unmanned forklift is in a fault state, a third prompt sound is played and a light of a third attribute is displayed.

[0030] Optionally, placing the cargo at the second target position based on the triggering states of the plurality of in-position sensors and the detection data of the fork strain includes:

[0031] In the case where the cargo can contact the root of the cargo fork, when the triggering states of the plurality of in-position sensors are all non-triggered, it is determined that the unmanned forklift safely places the cargo;

[0032] In the case where the cargo cannot contact the root of the fork, the torque is calibrated based on the detection data of the fork strain;

[0033] Based on the torque, placing and re-inserting the load so that the load can contact the base of the forks;

[0034] The cargo is re-placed based on the triggering status of the plurality of in-position sensors.

[0035] Optionally, the method further comprises:

[0036] When encountering an emergency, the unmanned forklift can be stopped by the emergency stop switch.

[0037] In a second aspect, the present application also provides an unmanned forklift safe operation system, comprising:

[0038] The picking module is used to pick up the goods at the first target position based on the trigger status of multiple in-place sensors and the detection data of fork strain after receiving the command of the unmanned forklift to pick up the goods in the outdoor environment and when the fork is raised and lowered to a safe state;

[0039] The planning module is used to plan the operation path of the unmanned forklift carrying the goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0040] A control module, used to control the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0041] The unloading module is used to place the goods at the second target position when the unmanned forklift runs to the second target position and the fork is raised and lowered to a safe state based on the triggering state of multiple in-position sensors and the detection data of the fork strain.

[0042] In a third aspect, the present application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in the first aspect when executing the program.

[0043] In a fourth aspect, the present application further provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0044] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which implements the method described in the first aspect when executed by a processor.

[0045] The unmanned forklift safe operation method, system, equipment, medium and program product provided by the present application can safely insert and place goods through the trigger state of the sensor or the detection data of the fork strain, plan the safe operation path of the unmanned forklift, and control the safe operation of the forklift based on the trigger state of the obstacle avoidance sensor and the trigger state of the edge contact switch, thereby ensuring the safety of the unmanned forklift during outdoor loading and unloading, reducing the risk of accidents, and can improve operating efficiency, reduce operating costs, and improve the applicability of the unmanned forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present application or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 It is a flow chart of the safe operation method of the unmanned forklift provided by the present application;

[0048] Figure 2 This is one of the schematic diagrams of sensor layout locations for unmanned forklift equipment provided in this application;

[0049] Figure 3 This is the second schematic diagram of the sensor layout of the unmanned forklift equipment provided by this application;

[0050] Figure 4 It is a schematic diagram of the outdoor unmanned loading and unloading scene design provided by this application;

[0051] Figure 5 It is a schematic diagram of the location of the unmanned forklift profile scanner provided by this application;

[0052] Figure 6 It is a schematic diagram of the position of the strain gauge used for the strain detection of the forklift provided by the present application;

[0053] Figure 7 This is a schematic diagram of the case where the edge of the pallet provided by the present application is far away from the edge of the vehicle plate;

[0054] Figure 8is a schematic diagram of the unmanned forklift provided by the present application placing cargo at the second docking position;

[0055] Fig. 9 It is a structural schematic diagram of the unmanned forklift safe operation system provided by this application;

[0056] Fig.10 It is a schematic diagram of the structure of the electronic device provided by this application.

[0057] Reference numerals:

[0058] 1: Obstacle avoidance radar; 2: Edge switch; 3: Wire encoder; 4: Warning light; 5: In-position sensor and in-position sensor; 6: Depth camera; 7: Upper and lower limit switches; 8: Clearance light; 9: Fork tip sensor; 10: Emergency stop switch; 11: Forward anti-collision edge switch. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solutions and advantages of this application clearer, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] Figure 1 This is a flow chart of the safe operation method of the unmanned forklift provided by this application. Figure 1 The embodiment of the present application provides a method for safe operation of an unmanned forklift, the execution subject of which may be an electronic device, for example, a controller. The controller is connected to a sensor system, a control system and a dispatching system.

[0061] The sensor system detects various sensor signals, and the sensor detection signals are reported to the dispatching system and control system according to priority.

[0062] The dispatch system determines the safe operation status based on the detection results of the sensor system, including whether a signal is received or whether the signal is consistent with expectations.

[0063] The dispatching system issues instructions to the control system based on the safety situation to continue the process, terminate the process, or continue waiting.

[0064] The control system receives the dispatching system instructions or sensor system instructions according to the priority, and controls the forklift to make corresponding control actions.

[0065] The forklift equipment provided in the embodiment of the present application includes a motion system and a sensor system. The motion system executes instructions issued by the control system, and the sensor system collects sensor detection signals.

[0066] Methods for safe operation of unmanned forklifts can include:

[0067] Step 110: after receiving the instruction of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is lifted and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain;

[0068] Step 120: based on the position of the unmanned forklift and the safe activity area of ​​the unmanned forklift, plan the operation path of the unmanned forklift carrying the goods;

[0069] Step 130: Control the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor, and the triggering state of the edge switch;

[0070] Step 140: When the unmanned forklift runs to the second target position, when the fork is raised and lowered to a safe state, the cargo is placed at the second target position based on the trigger states of the multiple in-position sensors and the detection data of the fork strain.

[0071] When unmanned loading and unloading forklifts work outdoors, on the one hand, they have high requirements for the safety of the area and require external vehicles and personnel to stay away. However, they have to face some emergencies outdoors, such as sudden intrusion of pedestrians, possible obstacles, and ensuring the safety of goods when loading and unloading. In this case, the unmanned loading and unloading forklifts must be designed for safety.

[0072] During the loading process, the safe operation method of the unmanned forklift can include the following steps:

[0073] In step 110, the controller goes to the first target location, i.e., the platform, to pick up the goods after receiving the pickup instruction issued by the dispatching system. After arriving at the platform, when the fork is lifted and lowered to a safe state, the controller can determine whether the fork is safely inserted into the goods through the trigger state of the in-place sensor. In particular, when the goods to be loaded and unloaded are heavy or have special insertion requirements or when the goods are not placed in a standardized manner, when the fork is lifted and lowered to a safe state, the controller can detect whether the weight of the inserted goods exceeds the standard or whether the goods are inserted in place through the trigger state of the in-place sensor and the detection data of the fork strain.

[0074] Figure 2 This is one of the schematic diagrams of the sensor layout of unmanned forklift equipment. Figure 3 This is the second schematic diagram of the sensor layout of unmanned forklift equipment. The layout of each sensor can be referred to Figure 2 , Figure 3 .

[0075] Specifically, the outdoor unmanned loading and unloading scene design is as follows: Figure 4As shown in the figure, the entire area consists of the platform, parking lines and adjacent areas, which are divided into unmanned loading and unloading vehicle operation areas and activity areas. The activity area refers to the area outside the parking lines and platforms in the area, where forklifts are only responsible for path planning and transfer; the operation area refers to the intersection of the platform pick-up and delivery area and the activity area, as well as the intersection of the truck parking lines and the activity area.

[0076] In the activity area, the forklift only moves on its own and does not involve picking up and placing goods. The forklift can autonomously plan its path and move according to the surrounding environment and has a certain degree of adaptability to changes in the surrounding environment. However, it should also meet the following requirements: (1) The activity area must have obvious signs indicating that it is an unmanned operation area; (2) Only authorized personnel are allowed to enter the area, and authorized personnel must have an understanding of the forklift's autonomous movement mode when entering the area, and can roughly predict the forklift's next operation trajectory to ensure personnel safety; (3) Obstacles within a certain volume are allowed in the activity area without affecting operation, and authorized personnel shall conduct regular inspections. Since the operation area involves more complex operations such as cargo identification and picking up and placing goods, the regional safety requirements are higher than those of the activity area. Therefore, on the basis of the activity area, the following restrictions should be added: (1) No personnel are allowed to enter the operation area; (2) No obstacles are allowed in the operation area.

[0077] In step 120, after the controller detects that the cargo is safely inserted and the fork arm lifts the cargo to a certain distance, path planning and motion control can be performed. During the path planning process, the coordinates of the forklift currently obtained by high-precision positioning in the map can be detected. If the current forklift position is within the boundary of the safe activity area map of the unmanned forklift, path planning is performed to obtain the operation path. If the forklift position is outside the boundary of the safe activity area map of the unmanned forklift, the path planning report is abandoned and waited.

[0078] In step 130, during the motion control process after successful path planning, the controller determines whether an obstacle exists and whether the obstacle collides with the unmanned forklift by detecting the triggering status of the obstacle avoidance radar and the edge switch, and controls the unmanned forklift to operate safely in these cases.

[0079] In step 140, when the unmanned forklift runs to the second target position, that is, reaches the operation area near the parking space line, when the fork is raised and lowered in a safe state, it is determined whether the cargo is safely placed at the second target position based on the triggering state of multiple in-position sensors and the detection data of the fork strain. If the forklift is triggered by the forward edge contact during the process of reaching the cargo placement position, it is considered that the forklift mast is in contact with the vehicle, and it is necessary to reverse and re-identify the position; if the forklift detects that the forklift fork tip sensor is triggered during the operation, it is considered that there is an obstacle in front of the fork (possibly a vehicle, spilled cargo or platform) and the operation cannot continue, and the forklift stops and reports and waits.

[0080] During the unloading process, the safe operation method of the unmanned forklift is similar to that of the loading process. Specifically, when unloading, in step 110, the controller reaches the predetermined position to pick up the goods after identification by the camera, etc., and detects the detection data of the in-place sensor status and the fork strain during the forklift process to ensure the safe insertion of the goods. After unloading, the transfer path planning method and motion control method (i.e., the contents of steps 120 and 130) are consistent with those of loading. When releasing the goods to the platform, in step 140, i.e., during the releasing process, the controller detects the detection data of the in-place sensor status and the fork strain to ensure that the goods are placed in place and continue with the next process operation.

[0081] The safe operation method of an unmanned forklift provided in the embodiment of the present application safely inserts and places goods through the trigger state of the sensor or the detection data of the fork strain, plans the safe operation path of the unmanned forklift, and controls the safe operation of the forklift based on the trigger state of the obstacle avoidance sensor and the trigger state of the edge contact switch, thereby ensuring the safety of the unmanned forklift during outdoor loading and unloading, reducing the risk of accidents, and can improve operating efficiency, reduce operating costs, and improve the applicability of the unmanned forklift.

[0082] In one embodiment, the safety state of the fork lifting and lowering is determined based on the upper and lower limit proximity switches and the laser rangefinder;

[0083] Based on the trigger status of multiple in-place sensors and the detection data of fork strain, the goods are inserted at the first target position, including:

[0084] Determine the distance between the truck pallet and the edge of the unmanned forklift;

[0085] When the distance is less than the preset threshold, when the trigger status of multiple in-place sensors are all triggered, it is determined that the unmanned forklift can safely insert the goods;

[0086] When the distance is greater than or equal to a preset threshold, the unmanned forklift is controlled to travel to a first parking position based on the distance;

[0087] Lift the fork of the unmanned forklift and calibrate the torque based on the fork strain detection data;

[0088] Based on torque, control the unmanned forklift to pick up goods;

[0089] Control the unmanned forklift for picking up the goods to drive to the second docking position;

[0090] Place goods based on fork strain detection data;

[0091] Re-insert goods based on the trigger status of multiple in-place sensors.

[0092] Accordingly, in one embodiment, placing the cargo at the second target position based on the triggering states of the plurality of in-position sensors and the detection data of the fork strain includes:

[0093] In the case where the cargo can contact the root of the fork, when the triggering status of multiple in-position sensors are all non-triggered, it is determined that the unmanned forklift safely places the cargo;

[0094] When the cargo cannot contact the fork root, the torque is calibrated based on the fork strain detection data;

[0095] Based on the torque, place and re-insert the load so that it can contact the fork root;

[0096] Reposition goods based on the trigger status of multiple in-position sensors.

[0097] The present application ensures the safety of lifting and lowering the fork through the safety design of the mast and fork. Specifically, the mast and fork safety design method includes:

[0098] The gantry is equipped with upper and lower limit proximity switches for the fork to detect whether the fork is lifted or lowered to the limit;

[0099] The gantry is equipped with an encoder or laser rangefinder to measure the lifting height of the forks;

[0100] Furthermore, a forward anti-collision edge switch is installed in front of the gantry, at the height interval between the platform and the truck, to ensure that the gantry will not collide with the vehicle or the platform.

[0101] Specifically, when the encoder or laser ranging distance is 0 and the lower limit proximity switch signal is expected, the fork lifting and falling is in a safe state, otherwise the fork lifting and falling is in a fault state; when the upper limit proximity switch signal is expected and the encoder or laser ranging distance is the maximum value, the fork lifting and falling is in a safe state, otherwise the fork lifting and falling is in a fault state.

[0102] When the forklift is in the operating area, it is at the intersection of the platform and the truck. The fork safety design includes:

[0103] A depth camera is installed at the base of the forklift fork through a vertical rail to identify the specific location of the pallet and insert and remove the goods;

[0104] A sensor is installed at the base of the forklift fork to detect whether the cargo is inserted in place;

[0105] A position sensor is installed at the bottom of the forklift fork to detect whether the cargo is in place;

[0106] A photoelectric sensor is installed at the tip of the forklift's fork to detect whether the cargo is skewed during insertion and removal.

[0107] The forklift can identify the position of the pallet through the depth camera and insert it. When the signal from the in-place sensor is as expected, the fork lifting action will continue; otherwise, the fork lifting will not be performed and a fault will be reported.

[0108] When the forklift places the goods, it first determines that it has reached the loading position based on recognition by cameras, etc., and then lowers the fork to release the goods. When the signal from the in-position sensor is as expected, the fork stops dropping and moves back; otherwise, the fork continues to be lowered. If the distance measured by the encoder or rangefinder exceeds the height of the cargo pallet hole, the fork stops dropping and reports a fault.

[0109] In some embodiments, when the forklift is moving forward and using the fork to pick up the cargo pallet, if the fork tip sensor signal is consistent with the expected one, the forklift is in a safe state;

[0110] Otherwise, the operating status of the forklift is faulty.

[0111] When a forklift is loading and unloading a vehicle, in some cases, the fork must not be close to the base when inserting the cargo. In this case, the distance between the pallet and the base can be identified by contour scanning to determine the position of the pallet. Specifically, a horizontal contour scanner can be installed in the middle of the base of the two forks of the gantry. The scanner can scan and identify the pallet profile and detect the distance between the pallet and the base of the forks. Figure 5 This is a schematic diagram of the location of the unmanned forklift contour scanner.

[0112] When a forklift is performing loading and unloading tasks, in some cases, the fork is required to not be close to the root of the goods, or the goods are placed irregularly and difficult to get close to the root. The fork strain detection data (specifically, it can be achieved through strain gauges) can also be used to detect the position of the goods. Figure 6 This is a schematic diagram of the location of strain gauges used for strain detection of unmanned forklift forks.

[0113] When the fork is inserting / placing goods, if the strain gauge reading is within the safe load range, the insertion / placing of goods is safe. If the strain gauge reading exceeds the safe load range of the fork, the controller controls the forklift to give up lifting the goods and report a fault.

[0114] In the process of unloading most non-standard cargo, the edge of the pallet is easily far away from the edge of the truck board due to the uneven placement of the truck pallet. Figure 7 This is a schematic diagram when the edge of the pallet is far from the edge of the truck. At this time, when the forklift is completely close to the truck, the cargo still cannot reach the root of the fork, so the in-position sensor cannot be triggered, and the traditional in-position sensor fails. The strain gauge can detect the in-position state of the cargo when the fork is lifted, and then judge the insertion and removal state of the cargo based on the in-position state to ensure safe operation.

[0115] Specifically, when unloading, the controller first uses the camera to determine the distance between the edge of the truck pallet and the edge of the unmanned forklift during insertion. If the distance is within the preset threshold, the insertion is normal, that is, insertion is performed through the triggering state of multiple in-place sensors; if the camera determines that the distance between the pallet and the edge of the vehicle is equal to or exceeds the preset threshold, the following process is entered: the controller controls the unmanned forklift to drive to the safe parking distance, that is, the first parking position, according to the distance to the edge of the vehicle, and then lifts the fork. At this time, the strain gauge values ​​on both sides are detected. If the goods on the left and right forks are correctly inserted, the strain gauge readings exceed the set threshold, and it is considered safe to insert, and then the forklift is controlled to retreat a certain distance to the second parking position according to the distance calculated by the camera, and the goods are placed again. The strain gauge value is monitored during the placement process. If the fork is separated from the pallet, the strain gauge reading is reset to zero, and it is considered safe to place. Figure 8 This is a schematic diagram of the unmanned forklift placing the cargo at the second docking position. After placement, the fork re-inserts the cargo to the root of the fork and then unloads the truck normally. In the above process, if the strain gauges of the left and right forks do not meet the threshold requirements, the insertion process is considered abnormal, and the process is terminated to avoid other accidents. The loading process is the same as above and will not be repeated.

[0116] Similarly, when placing goods, if the goods cannot contact the root of the fork, the controller can place and reinsert the goods based on the monitoring data of the strain gauge so that the goods can contact the root of the fork, and then safely place the goods based on the trigger status of multiple in-place sensors.

[0117] The steps to determine whether the unmanned forklift can safely insert / place goods based on the detection data of the strain gauge are as follows:

[0118] (1) The stress-strain detection of the strain gauge is introduced into the forklift's fork weight detection and in-position detection. Since the load-bearing principle of the forklift itself is similar to that of a lever, its load capacity decreases as it moves away from the center point. The load curve of the fork can actually be converted into torque. The torque calculation formula is as follows:

[0119]

[0120] This formula is equivalent to the forklift, It can be understood as torque. It can be understood as the weight of the goods. It can be understood as the location of the load center distance of the goods.

[0121] By detecting the strain at the fork root, according to The stress can be calculated and the current torque can be calibrated. represents stress, Represents the elastic modulus of the material, which is a constant. It's strain.

[0122] (2) The strain gauge outputs analog current through the full-bridge circuit. Changes in the fork load can cause current changes. The analog quantity is converted into digital quantity through the AD conversion module and transmitted to the controller. The controller converts the digital quantity into the corresponding torque. When inserting and removing goods, it can be judged whether the goods are overweight and the in-place status of the inserted goods based on the detected torque.

[0123] (3) The contour scanning function of the laser or ultrasonic radar scanner is applied to the fork in-place detection. The device is installed between the roots of the two forks. The device detects and identifies the scanned contour and determines the position of the cargo in the forks based on the detected contour distance information.

[0124] It is expandable. When inserting and removing goods, the eccentricity of the goods can be calculated based on the torque value of the two forks and the contour detection results. When the threshold is exceeded, the insertion can be abandoned to ensure the safety of picking and releasing goods.

[0125] The safe operation method of the unmanned forklift provided in the embodiment of the present application safely inserts and places goods through the trigger state of the sensor or the detection data of the fork strain, breaking the disadvantage that the conventional in-place / in-place sensors are limited by the installation position and can only detect the in-place status of the root of the fork, solving the problem that the traditional unmanned forklifts are difficult to load and unload non-standard goods, and also solving the problem of pallet deviation caused by irregular placement of pallets in outdoor unmanned loading and unloading vehicles or bumpy roads. The in-place status of the goods on the entire fork can be detected, not limited to the root of the fork, and at the same time, it can detect whether the weight of the inserted goods exceeds the bearing range of the fork according to needs, making the in-place and in-place position detection more flexible and more adaptable to complex scenarios.

[0126] In one embodiment, the operation of the unmanned forklift is controlled based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge switch, including:

[0127] When the unmanned forklift is traveling along the running path, it is determined whether there is an obstacle based on the triggering state of the obstacle avoidance sensor; and it is determined whether the unmanned forklift collides with the obstacle based on the triggering state of the edge contact switch;

[0128] When there are no obstacles and the unmanned forklift does not collide with the obstacles, control the unmanned forklift to continue running;

[0129] When there is an obstacle and the unmanned forklift collides with the obstacle, control the unmanned forklift to stop;

[0130] When there is an obstacle and the unmanned forklift does not collide with the obstacle, the operating state of the unmanned forklift is adjusted based on the size of the obstacle, the distance of the obstacle and the position of the unmanned forklift.

[0131] During the motion control process after successful path planning, the controller can detect the triggering status of the obstacle avoidance radar and the edge switch. If they are not triggered, it is considered that there is no obstacle and the forklift is controlled to move along the planned path; if the obstacle avoidance radar is detected to be triggered and the edge switch is not triggered, the forklift will be decelerated, detoured, stopped and waited according to the size and distance of the obstacle and the current position of the forklift; if the edge switch is triggered, it is considered that the forklift has safely touched the edge and collided with the obstacle, and the forklift edge switch directly controls the controller to stop, report and wait.

[0132] The forklift activity area and operation area can be designed according to the platform, truck and ground conditions.

[0133] The platform is on the side close to the warehouse door. Each warehouse door corresponds to two platforms. The parking line is perpendicular to the platform and located between every two platforms. The area between the parking lines is considered as the forklift activity area; the position where the forklift picks up and puts goods on the platform and the truck is considered as the operating area.

[0134] When the forklift is in the activity area, it relies on high-precision satellite positioning or lidar positioning, etc. The driving boundary does not exceed the activity area, and the forklift map is slightly smaller than the activity area.

[0135] In some embodiments, the forklift is in a safe operating state if the positioning position of the forklift does not exceed the activity area, otherwise the forklift is in a fault state and stops operating.

[0136] The forklift is equipped with an obstacle avoidance laser or ultrasonic sensor at the bottom, and an edge sensor at the bottom. The sensor detection range covers the forward driving range and has a protection level of IP67 or above. If it is a laser sensor, it has the ability to resist outdoor sunlight interference to ensure normal operation in complex outdoor environments.

[0137] In some embodiments, if the forklift reaches the boundary of the activity area or an unknown obstacle enters the activity area, the sensor is triggered, and the forklift is controlled to slow down, detour, stop, etc. based on the position, size and other information of the monitored target object.

[0138] A side contact switch is installed at the bottom of the forklift. The normally closed switch is connected to the controller's soft emergency stop. When in the high position, the controller operates normally. When in the low position, the clutch is locked, the contactor is disconnected, and there is no travel or steering.

[0139] In some embodiments, if the laser or ultrasonic sensor fails or the motion control fails, the edge touch can still trigger parking through the controller to ensure safety.

[0140] The method for safe operation of an unmanned forklift provided in the embodiment of the present application controls the safe operation of the unmanned forklift by triggering the obstacle avoidance sensor and the edge contact switch, thereby ensuring the safety of the unmanned forklift loading and unloading process, reducing the risk of accidents, and improving operating efficiency, reducing operating costs, and improving the applicability of the unmanned forklift.

[0141] In one embodiment, the method for safe operation of an unmanned forklift further includes:

[0142] Determine the operating status of the unmanned forklift when it is traveling along the operating path;

[0143] When the unmanned forklift is in a safe operating state, a first prompt tone is played and a light of a first attribute is displayed;

[0144] When the distance between the unmanned forklift and the obstacle is less than the preset distance, a second prompt sound is played and a light of a second attribute is displayed;

[0145] When the unmanned forklift is in a fault state, a third prompt sound is played and a light of a third attribute is displayed.

[0146] When the unmanned forklift is in operation, it has warning and alarm functions. The sound and light alarm safety design methods include:

[0147] The unmanned forklift is equipped with an audible and optical alarm device on the top of the overhead guardrail;

[0148] The sound and light alarm has more than 3 alarm prompt tones. The first prompt tone is played in the safe state to remind pedestrians that AGV equipment is in operation and not to approach; the second prompt tone is played when a person approaches or an obstacle is detected to warn pedestrians to stay away; the third prompt tone is played in the fault state to remind staff to perform maintenance.

[0149] The sound and light alarm also has a contour light indication function, which reminds pedestrians not to approach at night or in areas with poor lighting.

[0150] The sound, light and electricity alarm should have more than three kinds of lights for alarm and warning, which should include: safety status light (light of the first attribute), which is generally green and constant; warning status light (light of the second attribute), which is generally red and flashes quickly; fault status light (light of the third attribute), which is generally yellow and flashes slowly.

[0151] The safe operation method of the unmanned forklift provided in the embodiment of the present application performs sound and light alarms when the unmanned forklift is in different operating states, thereby ensuring the safety of the unmanned forklift loading and unloading process and reducing the risk of accidents.

[0152] In one embodiment, the method for safe operation of an unmanned forklift further includes:

[0153] When encountering an emergency, the unmanned forklift can be stopped by the emergency stop switch.

[0154] The internal controller of the unmanned forklift is connected to a normally closed (large) emergency stop switch, which is connected in series with the controller power supply. When the switch is in the high position, the controller is powered on and operates normally. When the switch is in the low position, the controller power supply is cut off and the forklift stops running.

[0155] The large emergency stop switch is designed and arranged in an easily accessible position on the forklift body, such as the rear control box, one side of the cab, etc.

[0156] In some embodiments, if the laser or ultrasonic sensor fails, or the motion control or controller fails, safety can still be ensured by manually performing an emergency stop.

[0157] During the operation of the unmanned forklift, if an emergency occurs and forced stopping is required to ensure safety, the controller reminds the authorized personnel to press the large emergency stop switch at a position that is easy to touch for the forklift, and the forklift will be powered off and stopped.

[0158] The method for safe operation of an unmanned forklift provided in the embodiment of the present application controls the unmanned forklift to stop by an emergency stop switch in an emergency situation, thereby ensuring the safe operation of the unmanned forklift and reducing the risk of accidents.

[0159] The unmanned forklift safe operation system provided by the present application is described below. The unmanned forklift safe operation system described below and the unmanned forklift safe operation method described above can be referenced to each other.

[0160] Fig. 9 This is a schematic diagram of the structure of the unmanned forklift safety operation system provided by this application. Fig. 9 The unmanned forklift safe operation system provided in the embodiment of the present application may include:

[0161] The cargo pickup module 910 is used to, after receiving the command of the unmanned forklift to pick up cargo in the outdoor environment, pick up cargo at the first target position based on the trigger status of multiple in-place sensors and the detection data of the fork strain when the fork is lifted and lowered to a safe state;

[0162] A planning module 920, for planning a running path of the unmanned forklift carrying goods based on the position of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0163] A control module 930, configured to control the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0164] The unloading module 940 is used to place the goods at the second target position when the unmanned forklift runs to the second target position and the fork is raised and lowered to a safe state based on the triggering state of multiple in-position sensors and the detection data of the fork strain.

[0165] The unmanned forklift safe operation system provided in the embodiment of the present application safely inserts and places goods through the trigger state of the sensor or the detection data of the fork strain, plans the safe operation path of the unmanned forklift, and controls the safe operation of the forklift based on the trigger state of the obstacle avoidance sensor and the trigger state of the edge contact switch, thereby ensuring the safety of the unmanned forklift during outdoor loading and unloading, reducing the risk of accidents, and can improve operating efficiency, reduce operating costs, and improve the applicability of the unmanned forklift.

[0166] Specifically, the above-mentioned unmanned forklift safe operation system provided in the embodiment of the present application can implement all the method steps implemented by the method embodiment in which the execution subject is the controller, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0167] Fig.10 An example of a physical structure diagram of an electronic device is shown in FIG. Fig.10 As shown, the electronic device may include: a processor 1010, a communications interface 1020, a memory 1030 and a communication bus 1040, wherein the processor 1010, the communications interface 1020 and the memory 1030 communicate with each other through the communication bus 1040. The processor 1010 may call the logic instructions in the memory 1030 to execute the unmanned forklift safe operation method, for example including:

[0168] After receiving the command of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is raised and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain;

[0169] Plan the operation path of the unmanned forklift carrying goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0170] Controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0171] When the unmanned forklift runs to the second target position, when the fork is raised and lowered to a safe state, the cargo is placed at the second target position based on the triggering states of multiple in-position sensors and the detection data of the fork strain.

[0172] In addition, the logic instructions in the above-mentioned memory 1030 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., various media that can store program codes.

[0173] On the other hand, the present application also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the unmanned forklift safe operation method provided by the above methods, for example, including:

[0174] After receiving the command of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is raised and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain;

[0175] Plan the operation path of the unmanned forklift carrying goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0176] Controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0177] When the unmanned forklift runs to the second target position, when the fork is raised and lowered to a safe state, the cargo is placed at the second target position based on the triggering states of multiple in-position sensors and the detection data of the fork strain.

[0178] In another aspect, the present application further provides a computer program product, the computer program product comprising a computer program, the computer program may be stored on a non-transitory computer-readable storage medium, and when the computer program is executed by a processor, the computer can execute the steps of the unmanned forklift safe operation method provided by the above methods, for example, including:

[0179] After receiving the command of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is raised and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain;

[0180] Plan the operation path of the unmanned forklift carrying goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift;

[0181] Controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch;

[0182] When the unmanned forklift runs to the second target position, when the fork is raised and lowered to a safe state, the cargo is placed at the second target position based on the triggering states of multiple in-position sensors and the detection data of the fork strain.

[0183] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0184] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0185] It should also be noted that the terms "first", "second", etc. in the embodiments of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first" and "second" are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0186] In the embodiments of the present application, the term "and / or" describes the association relationship of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0187] "Determine B based on A" in the embodiments of the present application means that the factor A should be considered when determining B. It is not limited to "B can be determined based on A alone", but should also include: "Determine B based on A and C", "Determine B based on A, C and E", "Determine C based on A, and further determine B based on C", etc. In addition, it can also include taking A as a condition for determining B, for example, "When A meets the first condition, use the first method to determine B"; for another example, "When A meets the second condition, determine B", etc.; for another example, "When A meets the third condition, determine B based on the first parameter", etc. Of course, it can also be a condition that takes A as a factor for determining B, for example, "When A meets the first condition, use the first method to determine C, and further determine B based on C", etc.

[0188] In the embodiments of the present application, the term "plurality" refers to two or more than two, and other quantifiers are similar.

[0189] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for safe operation of an unmanned forklift, characterized in that: include: After receiving the command of the unmanned forklift to pick up the goods in the outdoor environment, when the fork is raised and lowered to a safe state, the goods are inserted at the first target position based on the trigger state of multiple in-place sensors and the detection data of the fork strain; Plan the operation path of the unmanned forklift carrying goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift; Controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch; When the unmanned forklift runs to the second target position, in the case where the fork is lifted and lowered to a safe state, the cargo is placed at the second target position based on the triggering states of multiple in-position sensors and the detection data of the fork strain; The method of inserting the cargo at the first target position based on the trigger status of the plurality of in-place sensors and the detection data of the fork strain comprises: Determine the distance between the truck pallet and the edge of the unmanned forklift; In the case where the distance is less than a preset threshold, when the triggering states of the multiple in-place sensors are all triggered, it is determined that the unmanned forklift safely inserts the cargo; When the distance is greater than or equal to a preset threshold, based on the distance, the unmanned forklift is controlled to travel to a first parking position; Lifting the fork of the unmanned forklift, and calibrating the torque based on the detection data of the strain of the fork; Based on the torque, the unmanned forklift is controlled to pick up the cargo; Control the unmanned forklift for picking up the goods to drive to the second docking position; placing goods based on the detection data of the fork strain; Re-inserting the goods based on the triggering status of the multiple in-place sensors; Placing the cargo at the second target position based on the triggering states of the plurality of in-position sensors and the detection data of the fork strain includes: In the case where the cargo can contact the root of the cargo fork, when the triggering states of the plurality of in-position sensors are all non-triggered, it is determined that the unmanned forklift safely places the cargo; In the case where the cargo cannot contact the root of the fork, the torque is calibrated based on the detection data of the fork strain; Based on the torque, placing and reinserting the load so that the load can contact the base of the forks; The cargo is re-placed based on the triggering status of the plurality of in-position sensors.

2. The method for safe operation of an unmanned forklift according to claim 1, characterized in that: The safety status of fork lifting and lowering is determined based on the upper and lower limit proximity switches and the laser rangefinder.

3. The method for safe operation of an unmanned forklift according to claim 1, characterized in that: The controlling the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch includes: When the unmanned forklift is traveling along the running path, judging whether there is an obstacle based on the triggering state of the obstacle avoidance sensor; and judging whether the unmanned forklift collides with the obstacle based on the triggering state of the edge contact switch; When there are no obstacles and the unmanned forklift does not collide with the obstacles, control the unmanned forklift to continue running; When there is an obstacle and the unmanned forklift collides with the obstacle, control the unmanned forklift to stop; When there is an obstacle and the unmanned forklift does not collide with the obstacle, the operating state of the unmanned forklift is adjusted based on the size of the obstacle, the distance of the obstacle and the position of the unmanned forklift.

4. The method for safe operation of an unmanned forklift according to claim 3, characterized in that: The method further comprises: Determining the operating state of the unmanned forklift when traveling along the operating path; When the unmanned forklift is in a safe operating state, a first prompt tone is played and a light of a first attribute is displayed; When the distance between the unmanned forklift and the obstacle is less than the preset distance, a second prompt sound is played and a light of a second attribute is displayed; When the unmanned forklift is in a fault state, a third prompt sound is played and a light of a third attribute is displayed.

5. The method for safe operation of an unmanned forklift according to claim 1, characterized in that: The method further comprises: When encountering an emergency, the unmanned forklift can be stopped by the emergency stop switch.

6. An unmanned forklift safe operation system, characterized in that: include: The picking module is used to pick up the goods at the first target position based on the trigger status of multiple in-place sensors and the detection data of fork strain after receiving the command of the unmanned forklift to pick up the goods in the outdoor environment and when the fork is raised and lowered to a safe state; The planning module is used to plan the operation path of the unmanned forklift carrying the goods based on the location of the unmanned forklift and the safe activity area of ​​the unmanned forklift; A control module, used to control the operation of the unmanned forklift based on the operation path, the triggering state of the obstacle avoidance sensor and the triggering state of the edge contact switch; The unloading module is used for placing the goods at the second target position when the unmanned forklift runs to the second target position and the fork is lifted and lowered to a safe state, based on the triggering state of multiple in-position sensors and the detection data of the fork strain; The method of inserting the cargo at the first target position based on the trigger status of the plurality of in-place sensors and the detection data of the fork strain comprises: Determine the distance between the truck pallet and the edge of the unmanned forklift; In the case where the distance is less than a preset threshold, when the triggering states of the multiple in-place sensors are all triggered, it is determined that the unmanned forklift safely inserts the cargo; When the distance is greater than or equal to a preset threshold, based on the distance, the unmanned forklift is controlled to travel to a first parking position; Lifting the fork of the unmanned forklift, and calibrating the torque based on the detection data of the strain of the fork; Based on the torque, the unmanned forklift is controlled to pick up the cargo; Control the unmanned forklift for picking up the goods to drive to the second docking position; placing goods based on the detection data of the fork strain; Re-inserting the goods based on the triggering status of the multiple in-place sensors; Placing the cargo at the second target position based on the triggering states of the plurality of in-position sensors and the detection data of the fork strain includes: In the case where the cargo can contact the root of the cargo fork, when the triggering states of the plurality of in-position sensors are all non-triggered, it is determined that the unmanned forklift safely places the cargo; In the case where the cargo cannot contact the root of the fork, the torque is calibrated based on the detection data of the fork strain; Based on the torque, placing and reinserting the load so that the load can contact the base of the forks; The cargo is re-placed based on the triggering status of the plurality of in-position sensors.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the unmanned forklift safe operation method as described in any one of claims 1 to 5 is implemented.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for safe operation of an unmanned forklift as claimed in any one of claims 1 to 5 is implemented.

9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for safe operation of an unmanned forklift as claimed in any one of claims 1 to 5 is implemented.

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