JP7490493B2 - Control device for article moving mechanism - Google Patents

Description

Embodiments of the present invention relate to devices (controllers) for controlling the operation of various mechanisms for moving objects (object moving mechanisms), such as robots for loading and unloading objects and automated guided vehicles for transporting objects.

At logistics centers for goods, various goods such as unloaded luggage, parts, and products are handled. For example, goods accumulated in an accumulation area are picked up by a loading robot and moved by a conveying device. The loading robot is, for example, a manipulator (robot arm) equipped with a tool (also called an end effector) for handling goods at the tip of the arm. The tool has a gripping mechanism (goods gripping mechanism) for gripping and picking goods from the accumulation area. A suction mechanism that sucks goods with air is widely used as the goods gripping mechanism. The conveying device transports the goods to the next process such as sorting or assembly. As the conveying device, for example, a belt conveyor, a roller conveyor, an automatic guided vehicle (hereinafter referred to as AGV (Automatic Guided Vehicle)), etc. are used.

The cargo handling robot and the AGV are examples of goods moving mechanisms, and are movable bodies that operate according to the formulated motion plans, which are formulated in advance taking into account work efficiency and safety. However, if an unexpected (unanticipated) change occurs in the operating environment of these movable bodies, problems may arise if they continue to operate according to the formulated motion plans. Hereinafter, such unexpected changes in the operating environment of the movable body are referred to as events. In other words, an event is a factor that triggers a change in the operating mode of the movable body. Examples of such events include when a worker or a cart enters the range of motion of the cargo handling robot, or when an article is not properly grasped by the article gripping mechanism. In addition, for example, when a worker or the like enters the travel path of the AGV, a delay in the operation of the AGV may cause a traffic jam or another AGV may enter the travel path. These are also considered to be events.

When these events occur, it is possible, for example, to temporarily stop the loading robot or AGV, re-formulate the operation plan, and then resume the operation of the loading robot or AGV according to the re-formulated operation plan. This makes it possible to avoid collisions between the loading robot or AGV and obstacles and prevent damage caused by items falling off, but the efficiency of loading and unloading work decreases by the time the loading robot etc. is temporarily stopped. When loading and unloading large quantities of diverse items quickly, it is necessary to improve work efficiency without stopping moving bodies such as loading robots and AGVs, even when an event occurs.

Patent No. 6123307 Japanese Patent No. 5904445

Therefore, we provide a control device that appropriately changes the operating mode of an item moving mechanism, such as a cargo handling robot or AGV, in response to the occurrence of an event without stopping the mechanism.

The control device of the embodiment is a device for controlling the operation of an article moving mechanism that moves an article, and includes an operation plan correction means and a control means. The operation plan correction means formulates a corrected operation plan by correcting the operation plan by delaying or advancing the passing time without changing the passing points among the set values of the operation plan formulated by setting a plurality of way points including a start point and an end point of the movement line of the article moving mechanism when the article moves, and the passing time when the article moving mechanism passes each way point. The control means operates the article moving mechanism from the start point to the end point based on the presence or absence of a factor that hinders the operation of the article moving mechanism on the movement line. At that time, when there is no factor that hinders the operation of the article moving mechanism on the movement line, the control means controls the operation of the article moving mechanism according to the operation plan, and when the factor exists, causes the operation plan correction means to formulate a corrected operation plan and controls the operation of the article moving mechanism according to the corrected operation plan. The operation plan correction means adds a way point of the article moving mechanism at the time of occurrence of the factor, and corrects the operation plan by delaying or advancing the passing time after the passing time of the added way point. The article moving mechanism is an article handling robot including a gripper that releasably grips an article, and an arm that is connected to the gripper by at least one joint and operates by rotating each joint around a predetermined axis from the start point to the end point together with the gripper. The motion plan is formulated by setting the angular velocity of each joint of the arm at a predetermined reference point such that the reference point of the arm passes through the via point at the passing time. The motion plan correction means resets the angular velocity to formulate a corrected motion plan such that the reference point of the arm passes through the via point later or earlier than the passing time.

1 is a block diagram of a loading/unloading device equipped with a control device according to a first embodiment; 5 is a diagram showing a time variation of a motion angle at a predetermined joint of an arm section, as an example of way point data in the first embodiment. FIG. FIG. 4 is a diagram showing an example of a table of waypoint data (waypoint data table) in the first embodiment. FIG. 13 is a diagram showing a time variation before correction of a motion angle at a specific joint of the arm section, as one aspect of via point data before correction in the first embodiment (an example of via point data set in a motion plan). FIG. 13 is a diagram showing time variations in the motion angle at a specific joint of the arm section after correction, as one aspect of the way point data before correction in the first embodiment (an example of way point data set in a motion plan). FIG. 4 is a diagram showing a control flow of an article movement process in the control device of the loading/unloading device according to the embodiment. FIG. 4 is a diagram showing a control flow of event processing in the control device of the loading/unloading device according to the embodiment. FIG. 11 is a block diagram of an automatic driving system including a control device according to a second embodiment. FIG. 13 is a diagram showing an example of a table of waypoint data (waypoint data table) in the second embodiment. FIG. 11 is a diagram showing a control flow of driving processing in a control device and a management device of an automated driving system according to a second embodiment.

The control device of the article moving mechanism according to the embodiment will be described below with reference to Figs. 1 to 10. The control device controls the operation of the article moving mechanism. The article moving mechanism is a variety of mechanisms for moving articles, such as a robot for loading and unloading articles and an automated guided vehicle (AGV) for transporting articles. The article is a tangible object that can be the subject of loading and unloading, such as parcels including home delivery, parcels, and postal items, and various parts and products. The article includes the article itself as well as a tangible object in a packaged or wrapped state. The aspect (shape, size, weight, material, etc.) of the article is assumed to be not uniform but diverse, but may be uniform. The article includes both an article whose shape is not freely deformable (hereinafter referred to as a boxed object) and an article whose shape is freely deformable (hereinafter referred to as a flexible object) in terms of its material (including the packaged or wrapped state). Loading and unloading includes various operations for moving articles, such as unloading, loading, and sorting.

First Embodiment
Fig. 1 is a block diagram of a loading/unloading apparatus 1 including a control device 2 according to this embodiment. The loading/unloading apparatus 1 is one of the devices constituting a logistics system operating in, for example, a logistics center, and performs various processes required for loading/unloading. In the example shown in Fig. 1, a loading/unloading robot 3 is applied as an article moving mechanism in the loading/unloading apparatus 1.

The loading/unloading device 1 includes a control device 2 , a loading/unloading robot 3 , a detection unit 4 , and a notification unit 5 .
The cargo handling robot 3 is a device that performs the actual cargo handling work in the cargo handling device 1, and picks up an item from the accumulation area and moves it to a destination area. The accumulation area is, for example, an area where various unloaded items are temporarily accumulated before being transported to the next process. The items in the accumulation area may be accumulated orderly, may be piled up in bulk, or may be placed individually. The destination area is, for example, an area for transporting the items to a sorting process, an assembly process, or the like. The accumulation area and the destination area are, for example, furniture that stores items, such as boxes, cages, and shelves, transport devices such as belt conveyors, roller conveyors, and carts, and workbenches for sorting, assembly, and the like.

The cargo handling robot 3 is, for example, a so-called robot arm that includes a gripping unit 31, an arm unit 32, and a gripping state detection unit 33, and moves an item from a collection area to a destination area by the movement (displacement) of the arm unit 32 together with the gripping unit 31. However, the cargo handling robot 3 can also be a SCARA robot (horizontal multi-joint robot), an XYZ stage, a linear actuator, or a combination of these, and it is sufficient to apply a cargo handling robot that has a movable range corresponding to the movement range of the item.

The gripping unit 31 is detachably attached to the tip of the arm unit 32 (arm tip) and has a gripping mechanism that releasably grips an item. Gripping is defined as a concept that encompasses all manners of holding an item, such as suction by a suction mechanism, pinching or gripping by multiple fingers or claws, or a combination of these. The gripping mechanism of the gripping unit 31 grips an item from the accumulation area and releases the gripped item in the destination area.

The arm unit 32 is connected to at least one joint and extends. The arm unit 32 is divided into multiple parts by the joints, and each part rotates around a predetermined axis (joint axis) at the joint by a servo motor or the like. As a result, the arm unit 32 operates together with the gripper 31 by rotating each joint together with the gripper 31 around the joint axis. The operation here is to assume a desired posture with respect to a predetermined reference surface (for example, the floor surface of a building of a logistics center) and to freely displace within a predetermined range. The predetermined range (i.e., the movable range) includes the accumulation area and the destination area of the goods. Therefore, by rotating each part of the arm unit 32 around the joint axis at an arbitrary angular velocity or angular acceleration, it is possible to displace the arm unit 32 relative to the accumulation area and the destination area. The number of joints and joint axes may be set arbitrarily according to the operation accuracy and movable range required of the arm unit 32.

The gripping state detection unit 33 detects the gripping state of the item in the gripping unit 31. For example, a pressure sensor that measures the suction pressure (vacuum pressure) of the item in the suction mechanism, a flow sensor that measures the flow rate of air supplied by the suction mechanism, a force sensor that measures the tactile sensation (torque) of multiple fingers or nails, an optical sensor that measures the distance between the gripping unit 31 and the item, an acceleration sensor that measures the acceleration of the gripping unit 31, etc. can be used as the gripping state detection unit 33. Alternatively, these sensors may be combined to form the gripping state detection unit 33. The detection result of the gripping state detection unit 33, that is, data on the gripping state of the item gripped by the gripping unit 31, is provided to the control device 2.

The detection unit 4 detects various information (data) required to operate the cargo robot 3 to grasp and move an item. The detection unit 4 has a first detection unit 41 and a second detection unit 42.

The first detection unit 41 detects the accumulation state of the items in the accumulation area, the release state of the items in the destination area, and the situation around the movement line of the loading and unloading robot 3 when moving the items from the accumulation area to the destination area. The accumulation and release states of the items are, for example, the position, outline, size, orientation, posture, overlap, boundaries, material, etc. of each accumulated or released item. The situation around the movement line of the loading and unloading robot 3 (simply the arm unit 32) is the presence or absence of obstacles around the movement line that prevent the movement line from being secured, such as workers, other items, other loading and unloading robots, carts, work tables, walls, pillars, etc., and their movement forward and backward.

As the first detection unit 41, for example, a 3D camera, a parallax camera, multiple 2D cameras, a spectroscopic camera, an optical sensor, or a combination of these can be applied. These cameras are arranged at predetermined positions where the accumulation area, the destination area, and the periphery of the traffic line are within the angle of view and can be focused. For example, these cameras can be arranged at any position such as a frame that divides the accumulation area or the destination area, or the ceiling or wall of the logistics center building. In addition to cameras, as the first detection unit 41, a laser range finder that oscillates and emits laser light and detects the laser light reflected from an object, a pressure sensor that detects the pressure of the floor surface of the logistics center building, etc. can also be applied.

The first detection unit 41 analyzes the detection results (for example, captured image data) and analyzes the accumulation and release of the items, and the situation around the movement line of the loading robot 3. Specifically, it analyzes the image data showing these, and outputs information for identifying attributes such as the position, outline, size, orientation, posture, overlap, boundary, material, etc. of each accumulated or released item, or information for identifying the presence or absence of obstacles around the movement line and their advance and retreat, as analysis data, to the control device 2. Note that such analysis of the detection results may be performed by the control device 2 instead of the first detection unit 41.

The situation around the movement path of the cargo handling robot 3 is analyzed by dividing the area into caution areas, danger areas, etc. according to the possibility of contact with an obstacle. For example, a caution area is an area where an obstacle will not come into contact with the arm unit 32, but may come into contact with the grasped item. A danger area is an area where there is a high risk of an obstacle coming into contact with the arm unit 32, in short, the movable range of the arm unit 32. Note that these caution areas and danger areas may be fixed ranges, or may be variable ranges according to the size of the grasped item, the movement path of the cargo handling robot 3, etc.

The second detection unit 42 detects the gripping state of the item gripped by the gripper 31. In other words, the second detection unit 42 detects the gripping state of the item in the gripper 31 from its appearance. That is, the second detection unit 42 and the gripping state detection unit 33 complement each other in terms of detection accuracy for the gripping state of the item. The second detection unit 42 detects the vibration, deformation, posture, tilt, etc. of the item gripped by the gripper 31 as the gripping state of the item.

The second detection unit 42 can be, for example, a 3D camera, a parallax camera, multiple 2D cameras, a laser range finder, or a combination of these. These are arranged at predetermined positions where the item held by the gripper 31 can be captured while the item moves. For example, the second detection unit 42 can be arranged at any position, such as on the ceiling or wall of a building in the logistics center.

The second detection unit 42 analyzes the detection results (for example, captured image data) and analyzes the gripping state of the item. Specifically, it analyzes the image data showing these, and outputs information for identifying the vibration, deformation, posture, tilt, etc. of the item gripped by the gripper 31 to the control device 2 as analysis data. Note that such analysis of the detection results may be performed by the control device 2 instead of the second detection unit 42.

When a predetermined notification state occurs, the notification unit 5 notifies surrounding workers of the occurrence. The predetermined notification state is, for example, a state in which an obstacle that prevents the cargo handling robot 3 from securing a traffic line is present, or a state in which an obstacle is predicted to enter the vicinity of the traffic line. The notification unit 5 can be a warning light, a monitor, a speaker, or a combination of these. When an obstacle is predicted to enter, the notification unit 5 turns on (blinks) a warning light, sounds a warning sound, plays or displays a warning message, irradiates a laser, or the like, to thoroughly inform and alert workers of the entry of an obstacle. For example, when an obstacle enters a caution area, the notification unit 5 only notifies workers by turning on (blinks) a warning light, irradiating a warning sound, playing or displaying a warning message, irradiating a laser, or the like. On the other hand, when an obstacle enters a danger area, in addition to the notification by the notification unit 5, a corrected motion plan is formulated (reformulation of the motion plan) by the motion plan correction means 22, as described below.

The control device 2 functions as a control unit in the loading and unloading device 1, and controls the operation of the loading and unloading robot 3, which is an article moving mechanism, as well as the detection unit 4 and notification unit 5. The control device 2 includes a CPU, memory, a storage device (storage means 24 described later), an input/output circuit, a timer, etc., and executes predetermined calculation processing. For example, the control device 2 reads various data via the input/output circuit, performs calculation processing using a program read from the storage device to the memory, and controls the operation of the loading and unloading robot 3, detection unit 4, and notification unit 5 based on the processing results. The control device 2 is connected to the loading and unloading robot 3, detection unit 4, and notification unit 5 via wired or wireless connection, and transmits and receives various data, calculation results, etc. between them when controlling their operation.

The control device 2 includes a motion planning means 21, a motion plan correction means 22, a control means 23, and a storage means 24. In this embodiment, as an example, the motion planning means 21, the motion plan correction means 22, and the control means 23 are configured as programs for executing a predetermined calculation process in the control device 2, and are stored in the storage means 24 and read out to memory. Note that the programs for each of these means may be stored on the cloud, and the control device 2 may communicate with the cloud as appropriate to make the desired program available. In this case, the control device 2 is configured to include a communication module with the cloud, etc. Alternatively, the storage means 24 may be configured on the cloud rather than as part of the control device 2.

The motion planning means 21 formulates a motion plan for the cargo robot 3. The motion plan is formulated by setting data on the waypoints (hereinafter referred to as waypoint data) of the cargo robot 3 when moving an item. In this embodiment, the waypoint data is a collection of data (data group) that indicates the motion mode of the cargo robot 3, specifically the motion mode of each joint of the arm unit 32, and includes data on the waypoints when the joints operate, the time of passing through the waypoints, angles, angular velocities, and angular accelerations. However, the angular acceleration can be omitted.

The waypoints are points on the line of movement through which a predetermined reference point of the arm unit 32 passes when the cargo handling robot 3 operates to move an article, and are multiple points including the start and end points of the line of movement. The reference point is an arbitrary point set to specify the displacement of the arm unit 32 during operation, such as the center point of the tip. A trajectory connecting adjacent waypoints on the line of movement is a trajectory along which the reference point of the arm unit 32 displaces along the line of movement. The trajectory corresponds to each section into which the line of movement is divided. The trajectory is set so that the operating load of the joints of the arm unit 32 is as small as possible (minimizing the operating load). Therefore, the trajectory, in other words the line of movement, is set in the joint coordinate system of the arm unit 32 based on inverse kinematics, and may or may not match a trajectory that linearly connects the waypoints over the shortest distance.

The passing time of a waypoint is, for example, the arrival time of the reference point of the arm unit 32 at a waypoint closer to the start point of the corresponding trajectory (entrance side waypoint) and the arrival time of a waypoint closer to the end point (exit side waypoint). The time difference between the passing time of the exit side waypoint and the passing time of the entrance side waypoint is the time it takes for the reference point of the loading robot 3, specifically the arm unit 32, to displace along each trajectory, that is, the time it takes for each joint of the arm unit 32 to operate while the reference point is displaced. The angle is the angle (rotation angle) at which the joint rotates around the joint axis when the joint is operated along the trajectory. The angular velocity is the rotation speed relative to the rotation angle, and the angular acceleration is the rotation acceleration relative to the rotation angle (time derivative of the rotation speed).

Figure 2 shows an example of waypoint data, which is the time variation of the operating angle at a specific joint (joint 1) of the arm unit 32. In the example shown in Figure 2, n+1 waypoints P0 to Pn are set on the movement line (only seven waypoints are shown in the drawing). Waypoint P0 is the start point of the movement line of the reference point of the arm unit 32, and waypoint Pn is the end point of the movement line. Adjacent ones of these n+1 waypoints are connected to set n trajectories R1 to Rn. The joint unit 1 operates on each of these n trajectories at a set angle at a set time (T). The operation time of the joint unit 1 on each trajectory R1 to Rn is expressed as (tn)-(tn-1) (n is a natural number).

The motion planning means 21 has a trajectory setting unit 211, an interference checking unit 212, a passage time setting unit 213, and a motion plan formulation unit 214 in order to set waypoint data and formulate a motion plan.

The trajectory setting unit 211 sets the trajectory of the reference point of the arm unit 32. Specifically, the trajectory setting unit 211 sets a via point of the reference point, and sets the trajectory according to the via point. As a result, a movement line of the reference point of the arm unit 32 (hereinafter simply referred to as a movement line) is provisionally generated.

The interference check unit 212 judges whether the trajectory set by the trajectory setting unit 211 can actually be set. In making the judgment, the interference check unit 212 acquires data on the situation around the movement line of the cargo handling robot 3 detected and analyzed by the first detection unit 41, such as analysis data on the presence or absence of obstacles around the movement line and their advance and retreat. Based on the acquired analysis data, the interference check unit 212 judges whether the trajectory can be set. For example, the interference check unit 212 judges that the trajectory can be set when there is no obstacle around the movement line, when the obstacle can be avoided even if it exists, or when it is possible to predict that the obstacle will retreat from the periphery of the movement line. In contrast, for example, when an obstacle exists around the movement line and it is not possible to predict the obstacle's retreat from the periphery of the movement line, the interference check unit 212 judges that the trajectory cannot be set. In this case, the trajectory setting unit 211 resets the trajectory, and the interference check unit 212 judges whether the reset trajectory can be set. By repeating these steps, the trajectory setting unit 211 sets a trajectory that can actually be set without interference from obstacles.

The passing time setting unit 213 sets the time (passing time) at which the reference point of the arm unit 32 passes each way point set by the trajectory setting unit 211. The passing time setting unit 213 may set the displacement time of the reference point on the trajectory instead of or in addition to the passing time. The displacement time is the elapsed time (passing time difference) from when the reference point reaches the entrance way point of the trajectory to when it reaches the exit way point.

The motion planning unit 214 sets the angle, angular velocity, and angular acceleration for rotating each joint of the arm unit 32 around the joint axis at the passing time of the way point set by the passing time setting unit 213. The motion planning unit 214 then sets way point data by linking the way point of the reference point of the arm unit 32 set by the trajectory setting unit 211 and the passing time of the way point set by the passing time setting unit 213 with the angle, angular velocity, and angular acceleration at the way point of each joint, and formulates a motion plan for the loading and unloading robot 3. The motion planning unit 214 sets the way point data for each joint of the arm unit 32 (joint 1 to joint X), and stores the table (way point data table TB1) in the storage means 24.

Figure 3 shows an example of how via point data is stored as a table (via point data table TB1). As shown in Figure 3, the via point data is stored for each joint of the arm unit 32 (joint 1 to joint X) with the time of passing through the via point, angle, angular velocity, and angular acceleration linked to each other, and is managed, for example, in chronological order. Note that in this embodiment, angular acceleration is included in the via point data, but if angular acceleration is not included in the via point data, the angular acceleration item can be omitted in the via point data table TB1 shown in Figure 3.

When a factor (hereinafter referred to as an event) occurs that impedes the movement of each joint of the arm section 32 along the trajectory, or more simply, along the movement line, the motion plan correction means 22 formulates a corrected motion plan for the cargo robot 3. The corrected motion plan is a new motion plan for the cargo robot 3 that is re-formulated by modifying the motion plan formulated by the motion planning means 21. Specifically, of the waypoint data of the motion plan formulated by the motion planning means 21, the motion plan correction means 22 corrects the passing time, angular velocity, and angular acceleration. The factors that impede the movement of each joint of the arm section 32 along the trajectory, and whether they exist or not, will be described later.

The motion plan correction means 22 has a passage time correction unit 221 and a corrected motion plan formulation unit 222 to correct the waypoint data (in other words, the motion plan) and formulate a corrected motion plan.

The passage time correction unit 221 delays or advances the passage time of each set waypoint to reset the passage time. Note that if the displacement time of the reference point on the trajectory is set by the passage time setting unit 213 of the motion planning means 21, the passage time correction unit 221 may extend or shorten the set displacement time to reset the displacement time.

The corrected motion plan formulation unit 222 resets the angle, angular velocity, and angular acceleration of each joint of the arm unit 32 to rotate around the joint axis at the passing time of the way point reset by the passing time correction unit 221 (i.e., the set corrected passing time). Then, the corrected motion plan formulation unit 222 links the way points set by the trajectory setting unit 211 and the passing times of the way points of each joint reset by the passing time correction unit 221 with the angular velocity and angular acceleration at the reset way points, corrects and resets the way point data, and re-formulates the motion plan of the cargo handling robot 3, that is, formulates a corrected motion plan. That is, the corrected motion plan formulation unit 222 maintains the way points (in other words, the trajectory) and angles of the way point data set by the motion plan formulation unit 214 without correcting them, and corrects only the passing time, angular velocity, and angular acceleration. The corrected motion plan formulation unit 222 resets the passing time, angular velocity, and angular acceleration of the corrected way point data for each joint of the arm unit 32, and stores and memorizes them in a storage means described later. If the waypoint data does not include angular acceleration, the reconfiguration of angular acceleration is omitted.

Now, an example of such correction of waypoint data in a motion plan will be described with reference to Figs. 4 and 5. Fig. 4 shows an example of waypoint data before correction, that is, a time variation before correction of the motion angle at a specified joint part (joint part 1) of the arm part 32, as an example of waypoint data set in a motion plan. Fig. 5 shows an example of waypoint data after correction, that is, a time variation after correction of the motion angle at a specified joint part (joint part 1) of the arm part 32, as an example of waypoint data set in a motion plan.

4, when an event occurs at time ti, the corrected motion plan formulation unit 222 adds the position of the reference point of the arm unit 32 at that time ti as a via point Pi. The corrected motion plan formulation unit 222 also adds the angle, angular velocity, and angular acceleration of the joint unit 1 at time ti to the via point data. The passage time correction unit 221 sets the amount of change in the passage time of the via point after time ti (the operation time of the joint unit 1 between the via points). In the example shown in FIG. 4 and FIG. 5, the operation time between adjacent via points is set to twice, and the total operation time of the joint unit 1 from the via point Pi to the via point Pend is doubled. In FIG. 4 and FIG. 5, black dots indicate via points before correction, and white dots indicate via points after correction. The via point P0 is the start point of the movement line, and the via point Pend is the end point of the movement line. In this case, the operating time of the joint 1 between adjacent way points before correction, that is, the passage time difference (δtm) between adjacent way points, is calculated as δtm = (tm) - (tm-1) (m is any natural number). Therefore, the passage times (Tm-1, Tm) of the corrected way points Pm-1, Pm have the relationship Tm = (Tm-1) + 2 x (δtm) between the passage time difference (δtm) between the adjacent way points Pm-1 and Pm.

Based on this, the corrective motion plan formulation unit 222 corrects the waypoint data by the following process. The corrective motion plan formulation unit 222 establishes the following formula (1) as the relationship between the angle of the waypoint data after time ti and the passing time.

Equation (1) is an Nth-order polynomial that converts the angle of the waypoint data into a function of time (the time at which the waypoint is passed). F(t) in equation (1) is the trajectory shown by the solid line in Figure 5. Here, N is calculated from the number of waypoints after time ti and the amount of data obtained as boundary conditions. For example, when the number of waypoints after time ti is k, the order N of equation (1) is N = k + 4 - 1 = k + 3, based on the angular velocity and angular acceleration at time ti and the end of the movement.

Then, the corrected motion plan formulation unit 222 calculates the following equations (2) and (3). Equation (2) is an equation for angular velocity obtained by differentiating equation (1) with respect to time t. Equation (3) is an equation for angular acceleration obtained by differentiating equation (2) with respect to time t.

Then, the corrected motion plan formulation unit 222 formulates the following formulas (4), (5), and (6) for formulas (1), (2), and (3) using the waypoint data as boundary conditions, and calculates the coefficients a0 to an.

Then, the corrected motion plan formulation unit 222 calculates the corrected angular velocity and angular acceleration at each waypoint using formulas (1), (2), and (3) into which the calculated coefficients a0 to an are substituted.

Instead of such a method of correcting the waypoint data of the motion plan, the position, velocity, and acceleration of the gripper 31 in a Cartesian coordinate system may be calculated, for example, by forward kinematics, and the above-mentioned calculations may be performed in the Cartesian coordinate system. After the calculations, the position, velocity, and acceleration of the gripper 31 after the motion change may be converted into the angular velocity and angular acceleration of the joint of the arm 32 by inverse kinematics.

The control means 23 has an arm control unit 231, a grip control unit 232, and an event determination unit 233.

The arm control unit 231 operates (rotates) each joint of the arm unit 32 according to either the motion plan formulated by the motion plan formulation unit 214 or the corrected motion plan formulated by the corrected motion plan formulation unit 222. Specifically, the arm control unit 231 drives the servo motor to rotate each joint at the angle, angular velocity, and angular acceleration set around the joint axis. At that time, if the event existence condition described later is not satisfied, the arm control unit 231 rotates each joint of the arm unit 32 at the angle, angular velocity, and angular acceleration set in the motion plan. As a result, the arm unit 32 operates on a trajectory with the difference in the passing time (operation time) set in the motion plan. On the other hand, if the event existence condition is satisfied, the arm control unit 231 rotates each joint of the arm unit 32 at the angle set in the motion plan, and the angular velocity and angular acceleration corrected in the corrected motion plan. As a result, the arm unit 32 operates on a trajectory with the difference in the passing time corrected in the corrected motion plan (corrected operation time). That is, the arm control unit 231 operates the cargo robot 3 from the start point to the end point of the movement line based on the presence or absence of a factor (event) that prevents the cargo robot 3 from moving properly on the trajectory.

The gripping control unit 232 controls the operation of the gripping mechanism of the gripping unit 31 to grip an item and release the gripped item. At that time, it selects an item to be gripped based on the attributes (accumulation state) of the items in the accumulation area detected and analyzed by the first detection unit 41, and sets a target position (target gripping position) for gripping the selected item, and gripping states such as suction pressure and clamping pressure.

The gripping control unit 232 identifies selected items from the group of items based on a predetermined selection criterion corresponding to the analysis data acquired from the first detection unit 41. The selection criteria include, for example, the height position in the group of items, the distance from the loading robot 3, the gap between other items, the position in the accumulation area, and the material of the item (including the packaged or wrapped state). Specifically, the gripping control unit 232 identifies as selected items the item that is highest in the group of items, the item that is closest to the loading robot 3, the item that is furthest from other items, the item that is near the center of the accumulation area, or the item that has a material that is predefined as an item that is easy to grip (adsorb). Alternatively, the gripping control unit 232 may identify selected items using these as a combination of selection criteria.

The gripping control unit 232 also controls the gripping force of the item by supplying and exhausting air to generate suction pressure (vacuum pressure) of the suction mechanism, adjusting the tension angle of the finger joints and claw joints, etc. Based on the attributes (release mode) of the item in the destination area detected by the first detection unit 41, it also sets a target position (target release position) for releasing the gripped item and a placement area after release, etc. For example, it controls the release force of the item (reduction in gripping force) by releasing the suction mechanism that is suctioning the item to the atmosphere and adjusting the relaxation angle of the finger joints and claw joints, etc.

In this way, the grip control unit 232 formulates a gripping plan for the item and controls the operation of the gripping mechanism of the gripping unit 31 in accordance with the gripping plan. When formulating the gripping plan, the grip control unit 232 sets various parameters as described above in order to control the operation of the gripping mechanism to grip and release the item.

The event determination unit 233 determines the event presence/absence condition. The event presence/absence condition is a condition for determining whether or not a factor (event) that impedes the movement of the cargo handling robot 3, specifically each joint of the arm unit 32, on the trajectory has occurred. In determining the event presence/absence condition, the event determination unit 233 acquires data on the surrounding conditions of the movement line of the cargo handling robot 3, for example, detected and analyzed by the first detection unit 41. Based on the acquired data, the event determination unit 233 determines the presence/absence of an event, for example, whether or not there is an obstacle that impedes the securing of the movement line of the cargo handling robot 3, whether or not an obstacle is predicted to enter the vicinity of the movement line, etc. Hereinafter, such an event presence/absence determination will be referred to as a determination of the first event presence/absence condition, as appropriate.

Instead of or in addition to the data on the surrounding conditions of the movement line of the cargo handling robot 3, the event determination unit 233 may acquire data on the gripping state of the object gripped by the gripper 31 detected and analyzed by the second detection unit 42, and data on the gripping state of the object detected by the gripping state detection unit 33. Based on the acquired data on the gripping state of the object, the event determination unit 233 determines whether or not an event exists, for example, whether the vibration, deformation, posture, tilt, etc. of the object gripped by the gripper 31 are within an allowable range. Specifically, it is possible to determine whether or not the inertial force generated in the gripped object by changing the angular velocity or angular acceleration of each joint of the arm unit 32 is approaching the allowable gripping force (such as suction pressure or clamping pressure) of the design of the gripper 31 as an upper limit. It is also possible to determine whether or not the measured values of a pressure sensor that measures the suction pressure (vacuum pressure) of the object or a force sensor that measures the tactile sensation (torque) of multiple fingers or nails are not appropriate values, and there is a risk that the object will fall off the gripper 31. Alternatively, it is possible to determine whether the object held by the gripper 31 is deformed or vibrated beyond an acceptable range. Hereinafter, such an event presence/absence determination will be referred to as a second event presence/absence condition determination.

Regardless of which determination is made as the event presence/absence condition, the event determination unit 233 provides the determination result to the operation plan correction means 22 (passage time correction unit 221, corrected operation plan formulation unit 222) and the notification unit 5.

In addition, the event determination unit 233 determines the motion plan correction condition when the event existence condition (first event existence condition, second event existence condition) is satisfied. The motion plan correction condition is a condition for determining whether or not the motion plan needs to be corrected. In determining the motion plan correction condition, the event determination unit 233 acquires, for example, data on the surrounding situation of the movement line of the cargo handling robot 3 detected and analyzed by the first detection unit 41. In addition, for example, the event determination unit 233 acquires data on the grip state of the item detected and analyzed by the second detection unit 42 and data on the grip state of the item detected by the grip state detection unit 33. The determination of the motion plan correction condition will be described in detail in the description of the control flow of the event processing described later. The event determination unit 233 provides the determination result of the motion plan correction condition to the motion plan correction means 22 (passing time correction unit 221, corrected motion plan formulation unit 222) and the notification unit 5.

The operation of the loading device 1 configured as above, specifically the process of moving an item from the accumulation area to the destination area (hereinafter referred to as the item moving process), will be described according to the control flow of the control device 2 with respect to the loading robot 3, the detection unit 4, and the notification unit 5. Figures 6 and 7 show the control flow of the control device 2 with respect to the loading robot 3, the detection unit 4, and the notification unit 5 in the item moving process.

When starting the item movement process, the cargo robot 3 is in its initial state. The initial state of the cargo robot 3 is a state in which the arm unit 32 is positioned at a reference position. The reference position is, for example, a position in which the arm unit 32 does not interfere with either the item accumulation area or the destination area.

When moving an item from the accumulation area to the destination area, the control device 2 has the detection unit 4 detect various information required for the item movement process (S101). Here, the first detection unit 41 detects the accumulation state of the item, the release state, and the surrounding conditions of the movement line of the loading robot 3, and analyzes the detection results. The first detection unit 41 provides the analysis data to the control means 23.

When the analysis data is provided, the gripping control unit 232 of the control means 23 formulates a gripping plan for the item (S102). As a result, the selected item, the target gripping position, the gripping mode (such as suction pressure and clamping pressure), the target release position, etc. are set as the gripping plan.

When the analysis data is provided, the motion planning unit 21 formulates a motion plan for the cargo handling robot 3 (S103). Specifically, the trajectory setting unit 211 sets waypoints for the reference point of the arm unit 32, and sets a trajectory according to the waypoints. The passage time setting unit 213 sets the passage time of the reference point of the arm unit 32 at each waypoint set by the trajectory setting unit 211. The motion planning unit 214 sets the angle, angular velocity, and angular acceleration for rotating each joint of the arm unit 32 around the joint axis at the passage time set by the passage time setting unit 213. The motion planning unit 214 stores and memorizes the waypoint data set for each joint of the arm unit 32 in the storage unit 24 (see FIG. 3).

Once the motion plan is formulated, the arm control unit 231 of the control means 23 operates (rotates) each joint of the arm unit 32 in accordance with the motion plan (S104). As a result, the gripping unit 31 is displaced together with the arm unit 32.

When the gripping unit 31 reaches the target gripping position, the gripping control unit 232 grips the selected item from the accumulation area (S105). The gripping control unit 232 sets the suction pressure to the pressure set in the gripping plan, for example, before the reference position of the gripping unit 31 (as an example, the center position of the tip) reaches the target gripping position. Alternatively, the gripping control unit 232 sets the clamping pressure to the pressure set in the gripping plan when the reference position of the gripping unit 31 reaches the target gripping position. This allows the gripping mechanism of the gripping unit 31 to appropriately grip the selected item.

With the selected item being gripped by the gripping mechanism, the arm control unit 231 continues the operation of each joint of the arm unit 32 in accordance with the motion plan (S106). In other words, the arm control unit 231 displaces the reference point of the arm unit 32 toward the set final waypoint (end point of the movement line). Note that if the motion plan formulated by the motion planning means 21 has been corrected by the motion plan correction means 22 in the event processing (S201 to S205) described below, the motion plan here becomes a corrected motion plan (corrected motion plan).

Next, the event determination unit 233 of the control means 23 determines the event presence condition (S107). As an example, the event determination unit 233 determines the first event presence condition. In determining the first event presence condition, the event determination unit 233 acquires data on the surrounding conditions of the movement line of the loading robot 3 detected and analyzed by the first detection unit 41. For example, if there is an obstacle that prevents the movement line from being secured, or if the intrusion of an obstacle into the vicinity of the movement line is predicted, the event determination unit 233 determines that the first event presence condition is satisfied. On the other hand, for example, if there is no obstacle that prevents the movement line from being secured, or if the intrusion of an obstacle into the vicinity of the movement line cannot be predicted, the event determination unit 233 determines that the first event presence condition is not satisfied.

As an event presence condition, the event determination unit 233 may determine a second event presence condition instead of or in addition to the first event presence condition. In determining the second event presence condition, the event determination unit 233 acquires data on the gripping state of the item detected (analyzed) by the second detection unit 42 and the gripping state detection unit 33. For example, if the vibration, deformation, attitude, tilt, etc. of the item gripped by the gripper 31 are within the allowable range, the event determination unit 233 determines that the second event presence condition is not satisfied. On the other hand, for example, if the vibration, deformation, attitude, tilt, etc. of the item gripped by the gripper 31 are not within the allowable range, the event determination unit 233 determines that the second event presence condition is satisfied.

If the event presence condition is met, the control means 23 executes a predetermined event process (S108). For example, if at least one of the first event presence condition and the second event presence condition is met, the event process is executed. Details of the event process will be described later.

On the other hand, if the event presence condition is not met, the arm control unit 231 determines whether the motion plan completion condition is met (S109). The motion plan completion condition is a condition for determining whether the motion of each joint of the arm unit 32 has been completed according to the motion plan. For example, the arm control unit 231 determines that the motion completion condition is met when the reference point of the arm unit 32 has reached the set final waypoint (end point of the movement line), and determines that the motion completion condition is not met when the final waypoint has not been reached.

If the operation completion condition is not met, the arm control unit 231 continues the operation of each joint of the arm unit 32 according to the operation plan (S106). In this case, for example, since the reference point of the arm unit 32 has not yet reached the set final waypoint (end point of the movement line), the operation of each joint of the arm unit 32 continues until the final waypoint is reached.

On the other hand, if the operation completion condition is met, the grip control unit 232 releases the item at the target release position (S110). This completes the movement process for the released item (selected item). At that time, the grip control unit 232 transmits a signal to the arm control unit 231 and the operation planning means 21 indicating that a series of controls (item movement process) in the operation plan of the cargo robot 3 for the selected item has been successfully completed. The control device 2 then continues the item movement process (S101 to S110) for moving the next item from the accumulation area to the destination area. That is, the control device 2 repeats the specified control while items are being accumulated in the accumulation area. Then, when there are no more items accumulated in the accumulation area, the item movement process ends.

Next, we will explain the event processing (S108) that is executed when the event existence condition is met in S107. Figure 7 shows the control flow of the control device 2 with respect to the cargo robot 3, the detection unit 4, and the notification unit 5 in the event processing.

In processing an event, the event determination unit 233 determines the motion plan correction condition (S201). For this purpose, the event determination unit 233 acquires data on the surrounding conditions of the movement line of the cargo handling robot 3 detected and analyzed by the first detection unit 41. For example, if an obstacle that prevents the securing of the movement line exists in a danger area and it is not possible to predict the escape of the obstacle from the danger area, the event determination unit 233 determines that the motion plan correction condition is satisfied. On the other hand, for example, if such an obstacle does not exist in the danger area, or if it exists but it is possible to predict that the obstacle will escape from the danger area, the event determination unit 233 determines that the motion plan correction condition is not satisfied. Hereinafter, the motion plan correction condition determined in this manner is referred to as the first motion plan correction condition. The event determination unit 233 may determine the motion plan correction condition by setting the requirement for the above determination as a caution area rather than a danger area. This makes it possible to differentiate the content (degree of correction) of the motion plan of the cargo handling robot 3, which will be described later, between a case where the motion plan correction condition is satisfied with the requirement being a danger area and a case where the motion plan correction condition is satisfied with the requirement being a caution area.

In place of or in addition to the analysis data of the surrounding conditions of the movement line of the cargo handling robot 3, the event determination unit 233 may acquire data on the gripping state of the item gripped by the gripper 31 detected and analyzed by the second detection unit 42, and data on the gripping state of the item detected by the gripping state detection unit 33. Based on the acquired data on the item gripping state, the event determination unit 233 determines that the motion plan correction condition is met, for example, if the vibration, deformation, posture, tilt, etc. of the item gripped by the gripper 31 exceeds the allowable range. On the other hand, for example, if the vibration, deformation, posture, tilt, etc. of the item gripped by the gripper 31 is within the allowable range, it determines that the motion plan correction condition is not met. Hereinafter, the motion plan correction condition determined in this manner is referred to as the second motion plan correction condition.

When the motion plan correction condition is satisfied, the corrected motion plan formulation unit 222 of the motion plan correction means 22 corrects the motion plan of the cargo robot 3 formulated by the motion planning means 21, and formulates a corrected motion plan (S202). For example, when at least one of the first motion plan correction condition and the second motion plan correction condition is satisfied, the motion plan is corrected and a corrected motion plan is formulated. Specifically, the passing time, angular velocity, and angular acceleration of the waypoint data of the motion plan are each corrected.

Next, the arm control unit 231 operates (rotates) each joint of the arm unit 32 according to the revised motion plan (revised motion plan) (S203). As a result, each joint of the arm unit 32 operates with the revised angular velocity and angular acceleration at the revised passage time.

Then, the notification unit 5 issues a predetermined notification (S204). For example, when the motion plan of the cargo robot 3 is modified and each joint of the arm unit 32 is operating according to the modified passing time, angular velocity, and angular acceleration, the notification unit 5 notifies surrounding workers of this. This notification serves as a warning to thoroughly inform surrounding workers of the change in the motion mode of the cargo robot 3 and to draw their attention to it. In other words, this notification is issued so that surrounding workers are not inconvenienced by the angular velocity and angular acceleration of each joint of the arm unit 32 slowing down or speeding up.

In addition to or instead of such a notification by the notification unit 5, the operation of the cargo robot 3 may be stopped. For example, if the second operation plan correction condition is met in S201, there is a risk that the item may fall off the gripper 31, and by stopping the operation of the cargo robot 3, it is possible to further increase the safety of surrounding workers and items. The cargo robot 3 can be stopped, for example, by stopping the servo motor that rotates the joints, but a similar stopped state can also be achieved by infinitely extending the passing time after the reference point of the arm unit 32 is corrected.

In contrast, if the operation plan correction condition is not satisfied in S201, the notification unit 5 similarly issues a predetermined notification (S204). For example, if an obstacle is present in the attention area, if an obstacle is predicted to enter the attention area, or if these obstacles have retreated from the attention area, the notification unit 5 notifies surrounding workers of this. Also, for example, if the vibration, deformation, posture, tilt, etc. of the object grasped by the gripper 31 is likely to exceed the allowable range, the notification unit 5 notifies surrounding workers of this. This notification is intended to inform surrounding workers that an obstacle has entered the attention area or that the posture of the grasped object is unstable, and to draw their attention, even though there is no change in the operating mode of the cargo robot 3, specifically, the angular velocity and angular acceleration of each joint of the arm unit 32.

In addition to or instead of notifying surrounding workers as described above, the notification unit 5 may notify the upper management system of the loading/unloading device 1 that the operation plan has been modified. This allows, for example, the administrator of the upper management system to be notified of the modified operation plan, and makes it possible to reflect the modified operation plan in the operation control of the entire logistics system including the loading/unloading device 1.

In this way, according to the control device 2 of this embodiment, the motion plan of the cargo robot 3 can be modified in response to the occurrence of an event, and after the event occurs, the cargo robot 3 can be operated according to the modified motion plan (modified motion plan). When formulating the modified motion plan, the waypoints and angles of the waypoint data in the motion plan can be maintained without modification, and only the passage time, angular velocity, and angular acceleration need to be modified. Therefore, since there is no need to reset (recalculate) the waypoints, in other words the trajectory, the amount of calculation required when modifying the motion plan is small, and the motion plan can be modified almost in real time. Note that if the waypoint data does not include angular acceleration, there is no need to modify the angular acceleration, making it possible to further reduce the amount of calculation required when modifying the motion plan.

Therefore, even when an event occurs or is predicted to occur, the operating mode (passage time, angular velocity, and angular acceleration) can be appropriately changed without stopping the cargo robot 3. This allows the angular velocity and angular acceleration during rotation of each joint of the arm section 32 to be smoothly slowed or accelerated, regardless of whether an event has occurred, allowing the cargo robot 3 to operate smoothly. In addition, since stopping of the cargo robot 3 due to the occurrence of an event can be suppressed, the efficiency of cargo handling work can be improved.

In this embodiment, the control device 2 is described when the item moving mechanism is a cargo handling robot 3, but the item moving mechanism can be any mechanism that moves items and is not limited to a cargo handling robot 3. For example, the item moving mechanism may be an automated guided vehicle (AGV) that transports items. Below, an embodiment of the control device when the item moving mechanism is an AGV is described as a second embodiment.

Second Embodiment
Fig. 8 is a block diagram of an automatic driving system 100 including a control device 81 according to this embodiment. The automatic driving system 100 is a control system for automatically driving a plurality of AGVs 8 in, for example, a logistics center. The AGVs 8 correspond to an article moving mechanism in the automatic driving system 100. In the example shown in Fig. 8, the control device 81 is mounted on the AGVs 8.

The automatic driving system 100 includes a management device 7 and a plurality of AGVs 8 .
The management device 7 centrally manages the operation modes (travel modes) of the multiple AGVs 8. The management device 7 includes a CPU, memory, a storage device (a memory management unit 74 described later), an input/output circuit, a timer, etc., and executes predetermined calculation processing. For example, the management device 7 reads various data via the input/output circuit, performs calculation processing using a program read from the storage device to the memory, and controls the operation of each AGV 8 based on the processing results, while centrally managing them. The management device 7 is wirelessly connected to each of the multiple AGVs 8 via a communication network (network) NW, and transmits and receives various data, calculation results, etc. to and from them for operation control and centralized management.

The management device 7 includes an AGV management unit 71, a modification command unit 72, a communication management unit 73, and a memory management unit 74. In this embodiment, as an example, the AGV management unit 71, the modification command unit 72, and the communication management unit 73 are configured as programs for executing predetermined calculation processing in the management device 7, and are stored in the memory management unit 74 and read out to memory. Note that these programs may be stored on the cloud, and the management device 7 may communicate with the cloud as appropriate to make the desired programs available. In this case, the management device 7 is configured to include a communication module with the cloud, etc.

The AGV management unit 71 is an operation planning means for formulating an operation plan for each of the multiple AGVs 8. The operation plan is formulated by setting waypoint data for the AGVs 8 when traveling. In this embodiment, the waypoint data is a collection of data (data group) that indicates the operation mode of the AGVs 8, specifically the operation mode of the drive unit 83 described below, and includes data on the waypoints when the AGVs 8 operate (travel), the time of passing through the waypoints, the speed, and the acceleration. However, the acceleration can be omitted.

The waypoints are points on the flow line (travel path) that the AGV8 passes through when traveling, and are multiple points including the start and end points of the flow line. The start point of the flow line is the current position of the AGV7 (e.g., the warehouse of the goods), and the data of the current position is provided as estimated data by the control device 81 (specifically, the position estimation unit 8121 described later). The end point of the flow line is the destination of the AGV8 (e.g., the warehouse where the goods are shipped). The trajectory connecting each of the adjacent waypoints on the flow line is the trajectory along which the AGV8 travels along the flow line. The trajectory corresponds to each section that divides the flow line. The trajectory, in other words the flow line, is set in a Cartesian coordinate system, and may or may not match the trajectory connecting the waypoints in a straight line over the shortest distance.

The passing time of a waypoint is the time when the AGV8 passes each waypoint. For example, it is the arrival time at a waypoint closer to the start point of the trajectory (entrance waypoint), and the arrival time at a waypoint closer to the end point (exit waypoint). The time difference between the passing time at the exit waypoint and the passing time at the entrance waypoint is the time that the AGV8 operates on each trajectory (travels on each trajectory). The speed is the speed of the AGV8 at each waypoint. The acceleration is the acceleration of the AGV8 at each waypoint.

The difference is that the waypoint data deals with velocity and acceleration in a Cartesian coordinate system, rather than angular velocity and angular acceleration in a joint coordinate system, but the basic understanding of the waypoint data in this embodiment is similar to that of the waypoint data in the first embodiment described above. Therefore, the time variation of the operating angle at a specified joint (joint 1) of the arm unit 32 shown in FIG. 2 can be understood as an example of the time variation of the speed of a specified AGV 8.

The AGV management unit 71 stores the waypoint data (waypoint data table TB2) of each AGV8 in the memory management unit 74, which is a storage means. Note that this waypoint data may be stored on the cloud and the desired waypoint data may be made available by appropriately communicating with the cloud via the communication management unit 73, for example. In this case, the communication management unit 73 is configured to include a communication module with the cloud. Alternatively, the memory management unit 74 may be configured on the cloud rather than as part of the management device 7.

Figure 9 shows an example of how way point data is stored as a table (way point data table TB2). As shown in Figure 9, the way point data is stored for each AGV8 (AGV01 to AGV0x) with the passing time, speed, and acceleration of each way point (described later) linked to each other, and managed, for example, in chronological order. Note that in this embodiment, acceleration is included in the way point data, but if angular acceleration is not included in the way point data, the acceleration item can be omitted in the way point data table TB2 shown in Figure 9.

The correction command unit 72 selects an AGV8 for which the operation plan formulated by the AGV management unit 71 is to be corrected. That is, the operation plan formulated by the AGV management unit 71 is appropriately corrected. When a factor (event) that prevents a specific AGV8 from traveling properly occurs, the correction command unit 72 causes the control device 81 of the specific AGV8 (specifically, the corrected operation plan formulation unit 811 described later) to formulate a corrected operation plan. Examples of events include when the AGV8 cannot identify its current position, when a worker or the like enters the travel path of the AGV8, when a delay in the travel of the AGV8 (own vehicle) may cause a traffic jam or another vehicle to enter the travel path of the own vehicle. The corrected operation plan is a new operation plan for the AGV8 that has been re-formulated by correcting the operation plan formulated by the AGV management unit 71. Specifically, the correction command unit 72 corrects the passing time of the waypoint data of the operation plan formulated by the AGV management unit 71. The correction command unit 72 then generates a command (trigger data) that instructs the selected AGV8 to reset the waypoint data (correct the operation plan) based on the corrected passage time.

The communication management unit 73 transmits and receives various data and calculation results necessary for the operation of the AGV 8 to and from the AGV 8 (specifically, the communication unit 86 described later). For example, the communication management unit 73 transmits to the AGV 8 the operation plan formulated by the AGV management unit 71 (in other words, the set waypoint data) and the trigger data generated by the correction command unit 72. The communication management unit 73 also receives data on the current location and the occurrence of an event from each AGV 8 (the result of the determination of the event existence condition by the event determination unit 8123 described later).

The AGV8 automatically drives and transports goods from a current location (e.g., a warehouse for the goods) to a desired destination (e.g., a shipping area for the goods) without any human intervention. The AGV8 includes a control device 81, a storage unit 82, a drive unit 83, a detection unit 84, a memory unit 85, and a communication unit 86.

The storage section 82 is a component of the AGV 8 for storing items. For example, a box or shelf provided on the vehicle body (self-propelled portion) of the AGV 8, or a cart or cage cart towed by the vehicle body of the AGV 8, can be used as the storage section 82, and there is no particular limitation on its form.

The drive unit 83 is a component for driving the AGV 8. For example, the drive unit 83 includes a power source such as a motor or an engine, a transmission, tires, etc.

The detection unit 84 detects the surrounding conditions of the AGV 8. Examples of the surrounding conditions of the AGV 8 include the presence of workers, other AGVs, walls, pillars, etc. around the AGV 8's travel path. The detection unit 84 can be, for example, a 3D camera, a parallax camera, multiple 2D cameras, a laser range finder, or a combination of these. These are arranged at predetermined positions on the AGV 8 that can appropriately capture the front, rear, sides, etc. of the travel path.

The detection unit 84 analyzes the detection results (for example, captured image data) and analyzes the surrounding conditions of the AGV8. Specifically, the image data showing these is analyzed, and information for identifying the presence or absence of other AGV8s (hereinafter referred to as other vehicles) around the driving path of the AGV8 is output to the control device 81 as analysis data. Note that such analysis of the detection results may be performed by the control device 81, rather than by the detection unit 84. The surrounding conditions of the AGV8 may be analyzed by dividing the area into caution areas, danger areas, etc., depending on the degree of possibility of contact with other vehicles.

The memory unit 85 stores data necessary for running the AGV8. The stored data is, for example, map data including the travel route of the AGV8, waypoint data of the operation plan of the AGV8 described later, and the like. The storage image of the waypoint data is as shown in the waypoint data table TB2 shown in FIG. 9 above. However, the waypoint data stored in the memory unit 85 is only the waypoint data of the vehicle. In this embodiment, as an example, the memory unit 85 is separate from the memory device of the control device 81, but it may be part of the memory device. The memory unit 85 may also be a cloud. In this case, the communication unit 86 may be configured to include, for example, a communication module with the cloud.

The communication unit 86 transmits and receives various data and calculation results (signals) for controlling the operation of the AGV 8 (host vehicle) between the management device 7 (specifically, the communication management unit 73). For example, the communication unit 86 receives the operation plan (in other words, the set waypoint data) formulated by the AGV management unit 71 and the trigger data generated by the correction command unit 72. The communication unit 86 also transmits data on the current position (host vehicle position) of the AGV 8 estimated by the control device 81 (specifically, the position estimation unit 8121 described later) and the result of the determination of the event existence condition by the event determination unit 8123 described later.

The control device 81 functions as a control unit for the AGV8, which is an article moving device, and controls the operation (specifically, the traveling) of the AGV8. The control device 81 includes a CPU, memory, storage device (non-volatile memory), input/output circuits, a timer, etc., and executes predetermined calculation processing. For example, the control device 81 reads various data via the input/output circuits, performs calculation processing using a program read from the storage device to the memory, and controls the operation of the AGV8, more specifically the drive unit 83, detection unit 84, storage unit 85, and communication unit 86, based on the processing results.

The control device 81 includes a corrected motion plan formulation unit (motion plan correction means) 811 and a control means 812.

The corrected motion plan formulation unit 811 is a motion plan correction means for correcting the motion plan in the control device 81. When the corrected motion plan formulation unit 811 is instructed by the management device 7 to correct the motion plan, in short, to reset the waypoint data, the corrected motion plan formulation unit 811 resets the waypoint data according to the instruction content to correct the motion plan (formulates a corrected motion plan). Specifically, when the trigger data generated by the correction command unit 72 is received via the communication unit 86, the corrected motion plan formulation unit 811 formulates a corrected motion plan. In formulating the corrected motion plan, the corrected motion plan formulation unit 811 corrects the passing time, speed, and acceleration of the waypoint data of the motion plan formulated by the AGV management unit 71. The corrected passing time is set by the correction command unit 72 and given to the corrected motion plan formulation unit 811. Therefore, the corrected motion plan formulation unit 811 resets the speed and acceleration so that the AGV 8 passes the waypoint at the given passing time. The method for resetting the velocity and acceleration is similar to the method for calculating the corrected angular velocity and angular acceleration at each way point in the way point data in the first embodiment described above.

Then, the corrected motion plan formulation unit 811 links the waypoints of the AGV8 (host vehicle) set by the AGV management unit 71 and the passing times of the waypoints of the AGV8 reset by the correction command unit 72 with the speed and acceleration of the AGV8 at the reset waypoints, corrects and resets the waypoint data, and re-formulates the motion plan of the AGV8, that is, formulates a corrected motion plan. That is, the corrected motion plan formulation unit 811 maintains the waypoints (in other words, the trajectory) of the waypoint data set by the AGV management unit 71 as they are without correcting them, and corrects only the speed and acceleration according to the passing times reset by the correction command unit 72. The corrected motion plan formulation unit 811 stores the corrected waypoint data in the memory unit 85. Note that if the waypoint data does not include acceleration, the correction of acceleration is omitted.

The control means 812 automatically drives the AGV 8 from a current position (e.g., a warehouse for goods) to a desired destination (e.g., a warehouse for goods). The control means 812 has a position estimation unit 8121, a driving control unit 8122, and an event determination unit 8123.

The position estimation unit 8121 estimates the current position of the AGV8. The current position is the current vehicle position of the AGV8, which is the vehicle's traveling position if the vehicle is traveling, and the vehicle's stopped position if the vehicle is stopped. When making the estimation, the position estimation unit 8121 compares the analysis data of the detection unit 84 and the map data stored in the memory unit 85, for example, by matching the analysis data with the map data.

The driving control unit 8122 operates (drives) the AGV 8 according to the operation plan stored in the memory unit 85. If the operation plan formulated by the AGV management unit 71 has been revised by the revised operation plan formulation unit 811, the operation plan here becomes a revised operation plan (revised operation plan). In accordance with this operation plan, the driving control unit 8122 drives the AGV 8 along the traffic line (driving path) at the speed and acceleration set in the waypoint data. At that time, the driving control unit 8122 adjusts the output of the power source of the drive unit 83 to the set speed and acceleration, and drives the tires while appropriately changing the speed with the transmission.

The event determination unit 8123 determines the event presence/absence condition. The event presence/absence condition is a condition for determining whether an event as described above has occurred. In determining the event presence/absence condition, the event determination unit 8123 acquires, for example, data on the surrounding conditions of the AGV8 detected and analyzed by the detection unit 84, and data on the current position of the AGV8 estimated by the position estimation unit 8121. Based on the acquired data, the event determination unit 8123 determines whether an event exists, for example, whether the AGV8 can identify its own current position, whether a worker or the like has entered the travel path of the AGV8, whether there is a risk of traffic congestion or other vehicles entering the travel path of the AGV8 due to a travel delay of the AGV8 (own vehicle). The event determination unit 8123 provides the determination result to the correction command unit 72 via the communication unit 86 and the communication management unit 73.

The process of driving the AGV 8 configured in this way from its current position to its destination (hereinafter referred to as driving process) will be described according to the control flow of the control device 81 and management device 7 for the AGV 8. Figure 10 shows the control flow of the control device 81 and management device 7 for the AGV 8 in the driving process.

The state (initial position) of each AGV8 when the traveling process begins is not particularly limited; for example, all vehicles may be parked in the goods warehouse, or each vehicle may be distributed among the goods warehouse, the shipping area, etc.

When performing the travel process, the management device 7 formulates an operation plan for each AGV8 (S301). To this end, the AGV management unit 71 sets waypoint data for the operation plan. As waypoint data, the AGV management unit 71 sets the current position and destination of each AGV8, and also sets waypoints between them. The AGV management unit 71 also sets the passing time, speed, and acceleration for each waypoint.

When the operation plan is formulated, the management device 7 transmits the operation plan to the corresponding AGVs 8 (S302). This assigns the waypoint data of the operation plan to each AGV 8. The waypoint data is stored in the memory unit 85 of the AGV 8.

When the operation plan is transmitted and the waypoint data is assigned, the AGV8 operates (travels) according to the operation plan (S303). Specifically, the travel control unit 8122 of the control device 81 drives the drive unit 83 to cause the AGV8 to travel along the traffic line (travel route) at the speed and acceleration set in the waypoint data according to the operation plan read from the memory unit 85.

Next, the event determination unit 8123 of the control device 81 determines the event presence/absence condition (S304). In determining the event presence/absence condition, the event determination unit 8123 acquires data on the surrounding conditions of the AGV8 detected and analyzed by the detection unit 84, and data on the current position of the AGV8 estimated by the position estimation unit 8121. For example, if the AGV8 cannot identify its own current position, if a worker or the like has entered the driving path of the AGV8, or if there is a risk of congestion or entry of other vehicles into the driving path of the vehicle due to a driving delay of the AGV8 (own vehicle), the event determination unit 8123 determines that the event presence/absence condition is satisfied. On the other hand, for example, if the AGV8 can identify its own current position, if a worker or the like has not entered the driving path of the AGV8, or if there is no risk of congestion or entry of other vehicles into the driving path of the vehicle due to a driving delay of the AGV8 (own vehicle), the event determination unit 8123 determines that the event presence/absence condition is not satisfied. The event determination unit 8123 provides the determination result of the event existence condition to the modification command unit 72 of the management device 7 via the communication unit 86.

When the event existence condition is met, the modification command unit 72 generates a modification command for the operation plan formulated by the AGV management unit 71 (S305). The modification command is a command (trigger data) that instructs the AGV 8 to reset the waypoint data and formulate a modified operation plan. The modification command unit 72 modifies the passing time of the waypoint data of the operation plan formulated by the AGV management unit 71, and generates a modification command including the modified passing time. The modification command unit 72 gives the generated modification command to the modified operation plan formulation unit 811 of the control device 81 via the communication management unit 73.

The corrective operation plan formulating unit 811 determines whether or not there is a correction command (S306).
If a modification command has been issued from the modification command unit 72, the modified motion plan formulation unit 811 modifies the motion plan (S307). In making the modification, the modified motion plan formulation unit 811 reads the way point data of the motion plan from the storage unit 85, and modifies the passage time to the passage time issued by the modification command unit 72. Then, the speed and acceleration are reset so that the AGV 8 passes through the way point at the modified passage time, and the motion plan for the AGV 8 is re-formulated (modified motion plan is formulated). The modified motion plan formulation unit 811 stores the modified way point data in the storage unit 85.

Then, the AGV8 continues to operate (travel) according to the operation plan (S308). The operation plan here is an operation plan (modified operation plan) that is the operation plan formulated by the AGV management unit 71 and modified by the modified operation plan formulation unit 811. That is, the travel control unit 8122 causes the AGV8 to continue traveling along the traffic line (travel path) at the reset speed and acceleration.

If the event existence condition is not satisfied in S304, and if no correction command is given from the correction command unit 72 in S306, the AGV 8 similarly continues to operate (travel) according to the operation plan (S308). In this case, the operation plan formulated by the AGV management unit 71 is not modified, and the corresponding waypoint data is stored in the memory unit 85 without being reset. Therefore, the operation plan formulated by the AGV management unit 71 is applied as is here. In other words, the travel control unit 8122 causes the AGV 8 to continue traveling along the traffic line (travel route) at the speed and acceleration set by the AGV management unit 71.

While the AGV8 is traveling, the traveling control unit 8122 determines whether the operation plan completion condition is met (S309). The operation plan completion condition is a condition for determining whether the operation (travel) of the AGV8 has been completed according to the operation plan. For example, the traveling control unit 8122 determines that the operation completion condition is met if the AGV8 has reached the last set waypoint (end point of the flow line), in other words, the destination of the AGV8, and determines that the operation completion condition is not met if the last waypoint has not been reached.

If the operation completion condition is not met, the travel control unit 8122 causes the AGV8 to continue traveling according to the operation plan. In this case, for example, since the AGV8 has not yet reached the set final waypoint (destination), the AGV8 continues traveling until it reaches the final waypoint. At that time, the AGV8 continues traveling according to either the operation plan or the modified operation plan, depending on whether an event existence condition exists (S304) and whether a modification command has been issued (S306).

On the other hand, if the operation completion condition is met, the travel control unit 8122 stops the AGV 8 (S310). In this case, for example, assuming that the AGV 8 has reached its destination, the travel control unit 8122 stops the AGV 8 without continuing its travel. This completes the travel process for the stopped AGV 8. At that time, the travel control unit 8122 transmits a signal indicating that a series of controls (travel process) in the operation plan for the AGV 8 have ended normally to the AGV management unit 71 via the communication unit 86 and the communication management unit 73. Then, the management device 7 continues to perform the travel process (S301 to S310) for each AGV 8 until the travel process for all AGVs 8 is completed. Then, the management device 7 ends the travel process, for example, when all AGVs 8 have reached their destination and stopped.

As described above, the control device 81 of this embodiment provides the following advantageous effects in addition to the advantageous effects of the first embodiment described above.
In modifying the motion plan, the correction command unit 72 of the management device 7 resets the passing time of the waypoint, so that the processing load of the control device 81 can be reduced. Therefore, for example, the performance of the CPU, memory, storage device (non-volatile memory), etc. can be suppressed, and costs can be reduced. In addition, in modifying the motion plan, the calculation process for resetting the speed and acceleration of the AGV 8 is executed by the control device 81, not by the management device 7. Therefore, the amount of data communication between the AGV 8 and the management device 7 via the communication network NW can be suppressed. Therefore, the time lag during communication is suppressed, and the response from the occurrence of an event to the modification of the motion plan can be improved. Therefore, when an event occurs, the AGV 8 can be quickly changed to an appropriate traveling mode. Note that, if the waypoint data does not include acceleration, calculation processing for resetting the acceleration is not required, and the speed of calculation processing when modifying the motion plan in the control device 81 can be increased. In addition, in modifying the motion plan, it is not necessary for the management device 7 to reset all waypoint data of the motion plan of all the AGVs 8. Therefore, the processing load of the management device 7 can also be reduced.

Although several embodiments of the present invention have been described above, the above-mentioned embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1...loading device, 2...control device, 3...item moving mechanism (loading robot), 4...detection unit, 5...notification unit, 11...accumulation area, 12...destination area, 21...motion planning means, 22...motion plan correction means, 23...control means, 31...grasping unit, 32...arm unit, 33...grasping state detection unit, 41...first detection unit, 42...second detection unit, 211...trajectory setting unit, 212...interference check unit, 213...passing time setting unit, 214...motion plan formulation unit, 221...passing time correction unit, 222...corrected motion plan formulation unit, 231...arm control unit, 23 2...Grip control unit, 233...Event determination unit, 100...Automatic driving system, 7...Management device, 71...AGV management unit (motion planning means), 72...Modification command unit, 73...Communication management unit, 8...Item moving mechanism (AGV), 81...Control device, 82...Storage unit, 83...Drive unit, 84...Detection unit, 85...Storage unit, 86...Communication unit, 811...Modification motion plan formulation unit (motion plan modification means), 812...Control means, 8121...Position estimation unit, 8122...Driving control unit, 8123...Event determination unit, TB1, TB2...Way point data table.

Claims (7)

A control device for controlling an operation of an article moving mechanism that moves an article,
a motion plan modification means for formulating a modified motion plan by modifying the motion plan by delaying or advancing the passing times without changing the via points, among the set values of a motion plan formulated by setting a plurality of via points including a start point and an end point of a flow line of the article moving mechanism when the article is moved, and a passing time when the article moving mechanism passes through each via point;
a control means for operating the article moving mechanism from the start point to the end point based on the presence or absence of a factor that hinders the movement of the article moving mechanism along the flow line;
the control means controls the operation of the article moving mechanism in accordance with the operation plan when the factor does not exist, and causes the operation plan correction means to formulate the corrected operation plan and controls the operation of the article moving mechanism in accordance with the corrected operation plan when the factor exists;
the motion plan correction means adds a waypoint for the article moving mechanism at the time when the cause occurs, and corrects the motion plan by delaying or advancing the passage time after the passage time of the added waypoint;
the article moving mechanism is a loading and unloading robot including a gripping unit that releasably grips the article, and an arm unit that is connected to the gripping unit by at least one joint and operates by rotating each joint unit about a predetermined axis from the starting point to the end point,
the motion plan is formulated by setting an angular velocity of each joint of the arm unit at the via point so that a predetermined reference point of the arm unit passes through the via point at the passing time;
The motion plan correction means resets the angular velocity to formulate the corrected motion plan so that the reference point of the arm unit passes through the via point later or earlier than the passing time.
Control device. The control device according to claim 1 , wherein the motion plan correction means converts the angular velocity of each joint of the arm unit at each way point after the added way point into a function of time, and resets the angular velocity. The control device according to claim 1 , wherein the motion plan correction means sets the movement line in a joint coordinate system of the arm unit based on inverse kinematics. The control device according to claim 1 , wherein the control means determines whether or not the factor exists based on a determination condition including at least one of the presence of an intruding object in the traffic line and a holding state of the article. the article moving mechanism is a transport vehicle for the article, the transport vehicle including a storage unit that stores the article, and a drive unit that operates together with the storage unit from the starting point to the end point,
the operation plan is formulated by setting a speed of the transport vehicle at the waypoint so that the transport vehicle passes through the waypoint at the passing time;
The control device according to claim 1 , wherein the motion plan correction means formulates the corrected motion plan by resetting the speed so that the guided vehicle passes the waypoint later or earlier than the passing time. The control device according to claim 5 , wherein the motion plan correction means converts the speed of the transportation vehicle at each way point after the added way point into a function of time, and resets the speed. The transport vehicle is managed by a management device together with a plurality of other transport vehicles,
The control device according to claim 5 , wherein the operation plan correction means resets the speed based on the passage time corrected in the management device by delaying or advancing the passage time after the added waypoint.

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