Self-propelled mobile body and control method

Abstract

To temporarily suspend an operation plan easily even when a self-propelled mobile body is in the middle of movement according to the operation plan.SOLUTION: A self-propelled mobile body includes a motor that drives wheels, a control unit that controls the motor to drive the wheels based on an operation plan stored in a storage unit, and a first sensor that detects that an operator has pulled or pushed the self-propelled mobile body in a predetermined direction after receiving an operation for temporarily suspending the operation plan executed by the operator. The control unit causes the motor to generate a propulsive force or a braking force in the direction where the operator has pulled or pushed when the pulling or pushing action of the operator is detected by the first sensor.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a self-propelled mobile body and a control method.

Background Art

[0002] Some self-propelled mobile bodies capable of autonomous driving are equipped with detection sensors for detecting obstacles, and when an obstacle is detected in the traveling direction, they have a mechanism to stop in order to avoid risks such as collision with the obstacle (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, although the self-propelled mobile body as described above can perform operations (such as movement and transportation) without human intervention, when a person approaches to avoid danger, the operation stops, and the stopped state often continues until the danger is removed. For example, in a self-propelled mobile body that performs autonomous driving based on a pre-established operation plan, it is conceivable to perform control to avoid obstacles and proceed on its own, but such control is complex, and it takes a lot of time and cost to formulate an operation plan including obstacle avoidance.

[0005] In view of the above circumstances, one of the objects of the present disclosure is to provide a self-propelled mobile body and a control method that can easily temporarily interrupt the operation plan even during movement according to the operation plan.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a self-propelled mobile body including a motor that drives wheels and a control unit that controls the motor based on an operation plan stored in a storage unit to drive the wheels, the self-propelled mobile body including a coupling mechanism that couples an attachment carriage, and a first sensor provided in the coupling mechanism that detects that an operator has pulled or pushed the self-propelled mobile body in a state where the self-propelled mobile body and the attachment carriage are coupled by the coupling mechanism, and when the control unit receives an operation for temporarily interrupting the execution of the operation plan by the operator and then the first sensor detects that the operator has pulled or pushed, the control unit causes the motor to generate a driving force or a braking force in the direction in which the operator has pulled or pushed.

[0007] Also, one aspect of the present disclosure is a control method in a self-propelled mobile body including a motor that drives wheels, a coupling mechanism that couples an attachment carriage, and a control unit that controls the motor based on an operation plan stored in a storage unit to drive the wheels, the method including: a step in which, in a state where the self-propelled mobile body and the attachment carriage are coupled by the coupling mechanism, a first sensor provided in the coupling mechanism detects that an operator has pulled or pushed the self-propelled mobile body; and a step in which, after the control unit receives an operation for temporarily interrupting the execution of the operation plan by the operator and then the first sensor detects that the operator has pulled or pushed, the control unit causes the motor to generate a driving force or a braking force in the direction in which the operator has pulled or pushed.

Advantages of the Invention

[0008] According to the present disclosure, even when the self-propelled mobile body is in the middle of moving according to an operation plan, the operation plan can be easily interrupted temporarily.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0010] Hereinafter, the embodiment will be described with reference to the drawings. [Configuration of Self-Propelled Mobile Body] FIG. 1 is a perspective view showing an example of the external configuration of the self-propelled mobile body 1 according to the present embodiment. The self-propelled mobile body 1 shown in this figure is provided with a plurality of wheels 2 on the bottom surface so as to be movable. Further, the self-propelled mobile body 1 is provided with a connection mechanism 3 for coupling with the attached carriage 4. The attached carriage 4 includes support legs 5 provided at each of the four corners of the bottom surface and wheels 6 provided at the lower ends of the respective support legs 5, and can store articles inside the housing and move. Further, the attached carriage 4 is provided with a handle 7 as a gripping portion for the operator to grip. The operator can grip this handle 7 and move the attached carriage 4 alone.

[0011] Furthermore, the handle 7 is provided with a lock button (not shown). This lock button is an operator for locking or unlocking the connection between the attached cart 4 and the coupling mechanism 3. For example, by operating this lock button by the operator, the attached cart 4 can be detached from the coupling mechanism 3. By moving the self-propelled mobile body 1 with the connection between the attached cart 4 and the coupling mechanism 3 locked, the self-propelled mobile body 1 and the attached cart 4 can be connected and moved together.

[0012] FIG. 2 is a diagram showing an example of a state in which the self-propelled mobile body 1 according to the present embodiment and the attached cart 4 are connected. A space is formed below the attached cart 4 by the support legs 5, and a part of the self-propelled mobile body 1 is stored in this space and connected to the attached cart 4. Thereby, the self-propelled mobile body 1 and the attached cart 4 can be connected in a compact state, and for example, it can be made easier to move even in a narrow space.

[0013] FIG. 3 is a block diagram showing an example of the system configuration of the self-propelled mobile body 1 according to the present embodiment. The self-propelled mobile body system SYS shown in this figure includes the self-propelled mobile body 1 and the control server 50, and each is communicably connected via a wireless network NW. The control server 50 operates a control system for operating and managing the self-propelled mobile body 1, and can transmit and receive information and signals to and from the self-propelled mobile body 1 via the wireless network NW. For example, the control server 50 performs operation management of the self-propelled mobile body 1, that is, transmission and reception of operation plans and management of operation status.

[0014] The self-propelled mobile body 1 includes an operation plan storage unit 11, a map storage unit 12, a sensor 13, a control unit 14, a servo motor 15, and the like. The operation plan storage unit 11 stores data of an operation plan including execution of work (such as movement and transportation) of the self-propelled mobile body 1, work content and procedures for each work, and movement destinations. The data of the operation plan is transmitted from the control server 50 and updated.

[0015] The map storage unit 12 stores map data including information on the layout of obstacles such as buildings, passageways, walls, and pillars in the building where the self-propelled mobile body 1 performs operations such as movement and transportation, as well as information on the position of the destination. Note that the map data stored in the map storage unit 12 is not limited to indoor areas and may also include information on outdoor passageways and the layout of obstacles, as well as information on the position of the destination. The map data stored in the map storage unit 12 is also transmitted from the control server 50 and updated.

[0016] The sensor 13 is a sensor that detects surrounding obstacles when the self-propelled mobile body 1 performs operations (such as movement and transportation). For example, the sensor 13 includes at least one of a camera that images the surroundings and a distance sensor that detects the distance to an object existing in the surroundings. The sensor 13 will be described later with reference to FIG. 4.

[0017] The control unit 14 performs movement control of the self-propelled mobile body 1 based on information from the operation plan storage unit 11, the map storage unit 12, the sensor 13, etc. When performing movement control of the self-propelled mobile body 1, the control unit 14 controls the servo motor 15 to control the movement speed and movement direction of the self-propelled mobile body 1. The servo motor 15 is configured to include at least two motors, and each motor is independently connected to the left and right wheels 2. The control unit 14 can control the rotation direction and rotation speed of the left and right wheels 2 by controlling each motor, and move the self-propelled mobile body 1 in all directions. In addition, the servo motor 15 is provided with a current load detection unit 151. The current load detection unit 151 is configured to include a current sensor that detects the current change of the servo motor and a load sensor that detects the load torque of the servo motor 15. The current load detection unit 151 outputs speed information.

[0018] The operation record file 100 is a file that stores data such as the movement distance (displacement) and movement direction of the self-propelled mobile body 1 at regular intervals. The control unit 14 adds records at regular intervals, writes data such as the movement distance and movement direction of the self-propelled mobile body 1 in chronological order, and updates the operation record file 100. For example, the operation record file 100 is stored in the memory within the self-propelled mobile body 1.

[0019] FIG. 4 is a diagram for explaining an example of the configuration of the sensor 13 of the self-propelled mobile body 1 according to the present embodiment. This figure is a perspective view showing a state in which the self-propelled mobile body 1 and the attached carriage 4 are connected, and shows the side of the self-propelled mobile body 1. The self-propelled mobile body 1 includes a front panel 16 and a main body 17 provided with wheels 2 (see FIG. 1) on the bottom surface. As shown in the figure, the front panel 16 is provided so as to stand upright at the end of the main body 17. In this figure, the surface of the main body 17 on the side where the front panel 16 is provided (that is, the surface where the front panel 16 can be visually recognized) is hereinafter referred to as the front surface. Also, in the self-propelled mobile body 1, the direction in which the front panel 16 is located is referred to as the front, and the opposite direction is referred to as the rear.

[0020] The sensor 13 is configured to include a 3D camera 18 and a LiDAR (Light Detection and Ranging) 19. The 3D camera 18 is provided on the front surface of the front panel 16. The LiDAR 19 is provided on the front surface of the main body 17.

[0021] The 3D camera 18 is composed of a group of cameras directed in a plurality of directions and can image the surroundings of the self-propelled mobile body 1. The LiDAR 19 is a sensor that measures scattered light with respect to laser irradiation that emits light in a pulsed manner and measures the distance and direction to an object. In addition, instead of or in addition to the LiDAR 19, an infrared sensor, a sonar, or the like may be used. Instead of the 3D camera, a 2D camera may be used.

[0022] Although not constituting the sensor 13, a display device 20 is provided on the front panel 16. The display device 20 is configured to include, for example, a liquid crystal display, an organic EL display, or the like. Various types of information are displayed on the display device 20.

[0023] FIG. 5 is a diagram for explaining the connection mechanism 3 between the self-propelled mobile body 1 and the attached carriage 4 according to the present embodiment. FIG. 5(A) is a side view of the self-propelled mobile body 1, and FIG. 5(B) is a plan view of the self-propelled mobile body 1 as viewed from above. The connection mechanism 3 includes notches 21 and 22 provided in the self-propelled mobile body 1, and latches 31 and 32 and locking plates 33 and 34 provided in the attached carriage 4. Further, pressure-sensitive sensors 23 to 26 are provided in the connection mechanism 3. The notches 21 and 22 are recesses formed on the upper surface of the main body 17 of the self-propelled mobile body 1. Pressure-sensitive sensors 23 and 24 are respectively provided on the far side when viewed from the front panel 16 in each of the notches 21 and 22. Further, a pressure-sensitive sensor 25 is provided on the rear side surface of the main body 17 behind the notch 21. Furthermore, a pressure-sensitive sensor 26 is provided on the rear side surface of the main body 17 behind the notch 22.

[0024] On the other hand, latches 31 and 32 are respectively provided at positions corresponding to the notches 21 and 22 of the main body 17 on the attached carriage 4. Locking plates 33 and 34 project further rearward of the latches 31 and 32 of the attached carriage 4. The distance between the latch 31 and the locking plate 33 is slightly larger than the distance from the rear side surface of the notch 21 to the rear side surface of the main body 17. Similarly, the distance between the latch 32 and the locking plate 34 is slightly larger than the distance from the rear side surface of the notch 22 to the rear side surface of the main body 17.

[0025] FIG. 6 is a diagram for explaining the coupling mechanism 3 in a state where the self-propelled mobile body 1 according to the present embodiment and the attached carriage 4 are coupled. In a state where the self-propelled mobile body 1 and the attached carriage 4 are coupled, the main body 17 of the self-propelled mobile body 1 is stored in the lower space of the attached carriage 4, and each of the latches 31 and 32 engages with and is coupled to each of the notches 21 and 22. Specifically, the area of each concave portion of the notches 21 and 22 is larger than the area of each of the latches 31 and 32 facing the notches 21 and 22, and each of the latches 31 and 32 fits into the space of each concave portion of the notches 21 and 22, whereby the self-propelled mobile body 1 and the attached carriage 4 are coupled. Thereby, in the coupled state, the self-propelled mobile body 1 and the attached carriage 4 move integrally in the horizontal direction. For example, when the self-propelled mobile body 1 moves from the front of the attached carriage 4 into the lower space, the latches 31 and 32 automatically retract upward in response to contacting the rear side surface of the main body 17, and further, when they move to the positions of the notches 21 and 22, they automatically protrude in response to the recesses and are fitted with the notches 21 and 22 respectively. In a state where each of the notches 21 and 22 and each of the latches 31 and 32 are fitted, at least a gap is provided between the notch 21 and the latch 31 and between the notch 22 and the latch 32 respectively.

[0026] Also, when trying to store and couple the main body 17 of the self-propelled mobile body 1 in the lower space of the attached carriage 4, the rear side surface of the main body 17 contacts the locking plates 33 and 34 provided on the attached carriage 4 and is locked at that position, so that the coupling operation is easy. In addition, in order to further facilitate the coupling operation between the self-propelled mobile body 1 and the attached carriage 4, guide rails in the left-right direction may be provided to facilitate the alignment between the self-propelled mobile body 1 and the attached carriage 4.

[0027] When the operator grips the handle 7 (handles 7-1 and 7-2), the latches 31 and 32 are retracted upward, and the engagement between the latches 31 and 32 and the notches 21 and 22 is released. For example, when the operator grips the handle 7 (handles 7-1 and 7-2), a lock button (not shown above) is operated, and the latches 31 and 32 mechanically connected to the lock button are retracted upward.

[0028] In a state where the self-propelled vehicle 1 and the attached carriage 4 are connected, the pressure sensors 23 to 26 are provided at positions where they can detect the pressure generated when the operator pulls or presses the self-propelled vehicle 1 or the attached carriage 4. For example, the control unit 14 detects that the operator has pulled or pressed the self-propelled vehicle 1 in a predetermined direction based on the pressure detected by the pressure sensors 23 to 26 (an example of the first sensor). Details of the detection of pulling or pressing using the pressure sensors 23 to 26 will be described with reference to FIG. 8 below.

[0029] [Operation of the Self-Propelled Vehicle] Next, the operation of the self-propelled vehicle 1 will be described. When the control unit 14 detects that the operator has pulled or pressed the self-propelled vehicle 1, it causes the servo motor 15 to generate a driving force or a braking force in the direction in which the operator has pulled or pressed. Thereby, the self-propelled vehicle 1 can assist the pulling or pressing by the operator. Hereinafter, the operation mode in which the self-propelled vehicle 1 assists the pulling or pressing by the operator is referred to as the "assist mode".

[0030] (Transition to the Assist Mode) First, the transition from the normal operation mode that performs control based on the operation plan to the assist mode will be described. Various methods can be applied for the transition to the assist mode. For example, when the control unit 14 detects that the operator has grasped the handle 7, it may transition to the assist mode. Specifically, by providing a pressure sensor at the attachment part of the handle 7 or by providing a capacitance sensor on the surface of the handle 7, when these pressure sensors or capacitance sensors detect human contact, the control unit 14 may detect that the operator has grasped the handle 7 and transition to the assist mode.

[0031] In addition, when an operation is performed on the operation buttons displayed on the display device 20, the operation buttons provided on the housing of the self-propelled mobile body 1, or a remote controller (remote control) for remotely operating the self-propelled mobile body 1, etc., the control unit 14 may transition to the assist mode. Also, when the sensor 13 (3D camera 18 or LiDAR 19) detects the approach of a person, the control unit 14 may transition to the assist mode. Further, if the self-propelled mobile body 1 has a voice recognition function, the control unit 14 may transition to the assist mode by receiving an instruction by voice from the operator.

[0032] Also, a pressure sensor may be provided at the joint part between the front panel 16 and the main body 17, and when this pressure sensor detects pressure, the control unit 14 may transition to the assist mode. For example, when the operator tries to move the self-propelled mobile body 1 by directly pressing the front panel 16, the pressure sensor provided at the joint part between the front panel 16 and the main body 17 detects the pressure, and the control unit 14 may transition to the assist mode. Since the surface of the front panel 16 is relatively wide, the operator can easily touch it directly even in an emergency situation and can easily move the self-propelled mobile body 1.

[0033] (Assist mode) When shifting to the assist mode by any of the above methods, the control unit 14 starts controlling the self-propelled mobile body 1 in the assist mode. After shifting to the assist mode, it enters a standby state (a stopped state) until the operator pulls or presses the self-propelled mobile body 1. Note that after shifting to the assist mode, a braking operation may be actively performed while the operator has not yet pulled or pressed the self-propelled mobile body 1. Since it is dangerous to move inadvertently and unintentionally, there are cases where it is more suitable to perform the braking operation. Then, when the control unit 14 detects a pull or a press by the operator in a predetermined direction, it generates a propulsive force in the pulled or pressed direction.

[0034] FIG. 7 is a flowchart showing an example of the control process in the assist mode according to the present embodiment. First, the control unit 14 determines whether the assist mode is currently ON (step S001). For example, when the control unit 14 shifts to the assist mode triggered by the operator's grasping of the handle 7, it may determine that the assist mode continues to be ON while continuously detecting the grasping of the handle 7. On the other hand, when the control unit 14 no longer detects the grasping of the handle 7, it may determine that the assist mode has been turned off.

[0035] In addition, when the control unit 14 shifts to the assist mode triggered by the operator's operation on an operation button or a remote control, it may determine that the assist mode continues to be ON until a stop operation is performed on the operation button or the remote control, and determine that the assist mode has been turned off when the stop operation is performed. Also, when the control unit 14 shifts to the assist mode triggered by the sensor 13 detecting the approach of a person (e.g., the operator), it may determine that the assist mode continues to be ON while detecting the approach of the person, and determine that the assist mode has been turned off when a predetermined time has elapsed after the detection of the approach of the person has ceased.

[0036] When the control unit 14 determines that the assist mode has been turned off (step S001: NO), it proceeds to step S002 and shifts to the operation return mode (step S002). The operation return mode will be described later. On the other hand, when the control unit 14 determines that the assist mode is ON (step S001: YES), it proceeds to step S003 and controls the assist mode.

[0037] In the control of the assist mode, the control unit 14 acquires the detected values of the pressures detected by the pressure sensors 23 to 26 (step S003). Here, when the operator tries to move the self-propelled mobile body 1 forward, backward, or turn by pressing or pulling it, the pressure sensors 23 to 26 detect the pressure. The control unit 14 acquires from the pressure sensors 23 to 26 the detected values of the pressure due to the pressing or pulling on the self-propelled mobile body 1.

[0038] Next, the control unit 14 records in the operation record file 100 the data on the moving distance (displacement) and moving direction from the time when the detected values of the pressure sensors 23 to 26 were last acquired (step S004). In the operation record file 100, the data on the moving distance and moving direction from the start point of the assist mode are recorded in chronological order. This recorded data is later referred to in the operation return mode.

[0039] Note that the control unit 14 detects the moving distance and moving direction of the self-propelled mobile body 1 using, for example, odometry. As an example, the control unit 14 may detect the rotation amount of each wheel 2 and obtain the moving distance and moving direction based on the detected rotation amount of each wheel 2. Also, when the moving path is a factory or the like, the moving distance and moving direction may be detected by detecting white lines or the like drawn on the floor in the factory. Further, the control unit 14 may detect the moving distance and moving direction using a satellite positioning system or the like.

[0040] Next, the control unit 14 determines whether all the detection values of the pressure sensors 23 to 26 are "non-zero" ("pressure sensor detection value > 0") (step S005). When the control unit 14 determines that all the detection values of the pressure sensors 23 to 26 are "0" (step S005: No), it performs a braking operation (step S006).

[0041] The braking operation is an operation of reducing the output value of the servo motor 15 or, when the output value is already "0", adjusting the output value so as to generate a slight propulsive force in the direction opposite to the current moving direction of the self-propelled moving body 1. Thereby, when the operator pushes or pulls the self-propelled moving body 1, it becomes possible to feel an appropriate load. Also, when the self-propelled moving body 1 is stopped, it is possible to maintain the stopped state of the self-propelled moving body 1 by the braking operation. After performing this braking operation, the control unit 14 returns to step S001 and determines again whether the assist mode is ON.

[0042] On the other hand, when the control unit 14 determines that any of the detection values of the pressure sensors 23 to 26 is not "0" (step S005: YES), it classifies the pattern of the detection values of the pressure sensors 23 to 26 (step S007).

[0043] FIG. 8 is a diagram for explaining the pattern of the detection values of the pressure sensors 23 to 26 according to the present embodiment. As described above, since the pressure sensors 23 and 24 are provided on the rear side surfaces of the notches 21 and 22 where the latches 31 and 32 of the attached carriage 4 are fitted in a connected state, when a force to move the attached carriage 4 backward is applied, a pressure value corresponding to the force is detected. Also, since the pressure sensors 25 and 26 are provided on the rear side surface of the main body 17 at positions facing the front sides of the locking plates 33 and 34 of the attached carriage 4 in a connected state, when a force to move the attached carriage 4 forward is applied, a pressure value corresponding to the force is detected.

[0044] FIG. 8(A) is a diagram for explaining the pattern of detection values of the pressure sensors 23 to 26 during forward movement. For example, the reaction when the handle 7 of the attachment carriage 4 is pushed by an operator is detected by a pressure sensor provided in the coupling mechanism 3. When a force for moving the attachment carriage 4 forward (a force in the direction of the arrow indicated by reference numeral 201) is applied by pushing the handle 7 of the attachment carriage 4, the locking plates 33 and 34 abut against the pressure sensors 25 and 26 to apply pressure, and no pressure is applied to the pressure sensors 23 and 24. Therefore, as shown in the detection result of the pressure sensor indicated by reference numeral 202, the detection values of the pressure sensors 23 and 24 become "0", and the detection values of the pressure sensors 25 and 26 become values corresponding to the pressure ("non-0"). That is, when the detection values of the pressure sensors 23 to 26 are in the pattern shown by reference numeral 202, it means that the operator is trying to move the self-propelled mobile body 1 forward. Here, it is assumed that the operator grips the handle 7 and pushes (presses) the attachment carriage 4 from the rear side to the front to move the self-propelled mobile body 1 forward. However, even if the attachment carriage 4 is pulled (towed) from the front side to the front, the same pattern of detection values will be obtained.

[0045] FIG. 8(B) is a diagram for explaining the pattern of detection values of the pressure sensors 23 to 26 during backward movement. For example, the reaction when the handle 7 of the attachment carriage 4 is pulled by an operator is detected by a pressure sensor provided in the coupling mechanism 3. When a force for moving the attachment carriage 4 backward (a force in the direction of the arrow indicated by reference numeral 301) is applied by pulling the handle 7 of the attachment carriage 4, the latches 31 and 32 abut against the pressure sensors 23 and 24 to apply pressure, and no pressure is applied to the pressure sensors 25 and 26. Therefore, as shown in the detection result of the pressure sensor indicated by reference numeral 302, the detection values of the pressure sensors 23 and 24 become values corresponding to the pressure ("non-0"), and the detection values of the pressure sensors 25 and 26 become "0". That is, when the detection values of the pressure sensors 23 to 26 are in the pattern shown by reference numeral 302, it means that the operator is trying to move the self-propelled mobile body 1 backward. Here, it is assumed that the operator grips the handle 7 and pulls (tows) the attachment carriage 4 from the rear side to the rear to move the self-propelled mobile body 1 forward. However, even if the attachment carriage 4 is pushed (pressed) from the front side to the rear, the same pattern of detection values will be obtained.

[0046] Figure 8(C) is a diagram for explaining the detection value pattern of the pressure sensors 23 to 26 during a right turn. For example, when the operator grips the handle 7 and turns the attached cart 4 to the right, the reaction force is detected by the pressure sensors provided in the linkage mechanism 3. When turning the attached cart 4 to the right, the handle 7-1 held by the operator's right hand is pulled, and the handle 7-2 held by the operator's left hand is pushed. When a force to move the attached cart 4 backward (the force in the direction of the arrow indicated by reference numeral 401R) is applied due to the handle 7-1 being pulled, the latch 31 abuts against the pressure sensor 23 and pressure is applied, and no pressure is applied to the pressure sensor 24. Also, when a force to move the attached cart 4 forward (the force in the direction of the arrow indicated by reference numeral 401L) is applied due to the handle 7-2 being pushed, the locking plate 34 abuts against the pressure sensor 26 and pressure is applied, and no pressure is applied to the pressure sensor 25. Therefore, as shown by the detection results of the pressure sensors indicated by reference numeral 402, the detected values of the pressure sensors 23 and 26 become values corresponding to the pressure ("non-zero"), and the detected values of the pressure sensors 24 and 25 become "0". That is, when the detected values of the pressure sensors 23 to 26 are in the pattern shown by reference numeral 402, it means that the operator is trying to turn the self-propelled mobile body 1 to the right.

[0047] When turning to the left, since the handle 7-1 is pushed and the left handle 7-2 is pulled, contrary to the detection value pattern of the pressure sensors 23 to 26 shown by reference numeral 402 in Figure 8(C), the detected values of the pressure sensors 24 and 25 become values corresponding to the pressure ("non-zero"), and the detected values of the pressure sensors 23 and 26 become "0".

[0048] In this way, by classifying the detected values from the pressure sensors 23 to 26 into patterns, it becomes possible to sense how the operator wants to move the self-propelled mobile body 1 through the pressure sensors 23 to 26.

[0049] In the above description, the detection values of the pressure sensors 23 to 26 are discriminated between "0" and "non-0". However, the detection value of the pressure sensors 23 to 26 being "0" means that it is less than a preset first threshold value, and the detection value of the pressure sensors 23 to 26 being "non-0" means that it is equal to or greater than a preset second threshold value (the first threshold value < the second threshold value).

[0050] Returning to FIG. 7, the control unit 14 determines whether or not the pattern of the detection values of the pressure sensors 23 to 26 classified in step S007 has changed with respect to the pattern of the previous detection values (step S008). When the control unit 14 determines that there has been a change with respect to the pattern of the previous detection values (step S008: YES), it is presumed that the operator is trying to stop the movement of the self-propelled mobile body 1 or make fine adjustments. Therefore, the output value of the servo motor 15 is temporarily reset to the initial value and set to the minimum value according to the pattern of the detection values (step S009).

[0051] On the other hand, when the control unit 14 determines that there has been no change with respect to the pattern of the previous detection values (step S008: NO), it is presumed that the direction in which the operator is trying to move the self-propelled mobile body 1 has not changed. To reduce the force with which the operator pushes or pulls the self-propelled mobile body 1, the output value of the servo motor 15 is increased by only a predetermined value for adjustment (step S010).

[0052] As a result, it becomes possible for the operator to move the self-propelled mobile body 1 with little effort. Therefore, even during the intervals between operations based on a predetermined operation plan, it becomes easy to coexist the operation of the self-propelled mobile body 1 and the work of the operator. In addition, since the fine adjustment of the operation plan of the self-propelled mobile body 1 is left to the operation of the operator on-site, it becomes easy to formulate the operation plan of the self-propelled mobile body 1, the period from the introduction of the self-propelled mobile body 1 to actual operation can be shortened, and the operation cost can be reduced.

[0053] Subsequently, the control unit 14 determines whether the speed of the self-propelled mobile body 1 exceeds the upper limit value (step S011). For example, the control unit 14 can obtain the speed information of the self-propelled mobile body 1 from the current load detection unit 151 in the servo motor 15. In this case, the current load detection unit 151 corresponds to a speed detection unit that detects the speed of the self-propelled mobile body 1.

[0054] Note that the control unit 14 may also obtain speed information using the 3D camera 18 or the LiDAR 19. In this case, the 3D camera 18 or the LiDAR 19 corresponds to a speed detection unit that detects the speed of the self-propelled mobile body 1. Also, when the control unit 14 is equipped with an odometry that estimates its own position from the rotation angle of the wheels 2, the control unit 14 may obtain the speed information of the self-propelled mobile body 1 based on the time displacement of the self-position estimated using the odometry. In this case, the control unit 14 itself also functions as a speed detection unit that detects the speed of the self-propelled mobile body 1.

[0055] When the control unit 14 determines that the speed of the self-propelled mobile body 1 does not exceed the upper limit value (step S011: NO), it returns to step S001 and determines again whether the assist mode is ON. On the other hand, when the control unit 14 determines that the speed of the self-propelled mobile body 1 exceeds the upper limit value (step S011: YES), it performs a braking operation (step S012). This braking operation may be the same as the braking operation in step S006 described above.

[0056] In this way, since the control unit 14 controls the self-propelled mobile body 1 so that its speed does not exceed the limit, the operator can move the self-propelled mobile body 1 safely. For example, in the place where the self-propelled mobile body 1 is operated, there may be slopes or the like. When the operator pushes the self-propelled mobile body 1 down a slope, there is a risk that the speed will increase too much. When the self-propelled mobile body 1 is a robot, in order to prevent falling, its self-weight is often very heavy and may exceed 100 kg. Therefore, when the speed is too high, it is difficult and dangerous for the operator to apply braking. Furthermore, when the operator pushes the self-propelled mobile body 1 too strongly, there is also a risk of exceeding the speed limit, which may also cause an accident in that case. In the present embodiment, in the assist mode, by providing a speed limit, safer operation is made possible.

[0057] After performing the braking operation in this step S012, the control unit 14 returns to step S001, determines again whether the assist mode is ON, and repeats the above-described processing.

[0058] (Operation Resume Mode) Next, the processing of the control unit 14 in the operation resume mode will be described. After the assist mode ends, the self-propelled mobile body 1 moves itself back to the original point in the operation resume mode and resumes the execution of the interrupted operation plan. FIG. 9 is a flowchart showing an example of the control processing in the operation resume mode according to the present embodiment.

[0059] When shifting to the operation resume mode in step S002 of FIG. 7, the control unit 14 acquires the number of records in the operation record file 100 and sets the acquired number of records to the variable N (step S101). Then, the control unit 14 reads the Nth record of the operation record file 100 and acquires the displacement and direction (step S102).

[0060] Subsequently, the control unit 14 controls the servo motor 15 to move it 180° in the direction held in the Nth record by the amount of displacement held in the Nth record (step S103). Thereby, the self-propelled mobile body 1 can be moved to the position before the Nth record is recorded (the position where the (N - 1)th record is recorded).

[0061] Next, the control unit 14 decrements the value of the variable N by 1 (step S104). Then, the control unit 14 determines whether the variable N has become 0 (step S105). If it is determined that the variable N has not become 0 (step S105: NO), the processes of steps S102 to S104 are repeated.

[0062] On the other hand, when the control unit 14 determines that the variable N has become 0 (step S105: YES), since there are no more records to be processed, the operation resume mode is terminated and the normal operation plan is resumed. Thereby, the control unit 14 moves the self-propelled mobile body 1 to the position immediately before interrupting the operation plan and shifting to the assist mode, and then resumes the execution of the operation plan. That is, when ending the assist mode, the control unit 14 returns the self-propelled mobile body 1 to a position where the execution of the operation plan can be resumed and then resumes the execution of the operation plan.

[0063] [Summary of the Embodiment] As described above, the self-propelled mobile body 1 according to the present embodiment includes a servo motor 15 (an example of a motor) that drives the wheels 2, and a control unit 14 that controls the servo motor 15 based on an operation plan stored in a memory (storage unit) to drive the wheels 2. Further, the self-propelled mobile body 1 includes pressure-sensitive sensors 23 to 26 (an example of a first sensor) that detect that the operator has pulled or pushed the self-propelled mobile body 1 in a predetermined direction after receiving an operation that temporarily interrupts the execution of the operation plan by the operator. The operation for temporarily interrupting the execution of the operation plan is, for example, the operation described in the method of shifting to the assist mode described above. And when traction or pressing by the operator is detected by the pressure-sensitive sensors 23 to 26, the control unit 14 causes the servo motor 15 to generate a driving force or a braking force in the direction in which the operator has pulled or pushed.

[0064] Thereby, even while the self-propelled mobile body 1 is moving according to the operation plan, the operator can easily temporarily interrupt the operation plan only by pushing or pulling.

[0065] The self-propelled mobile body 1 also includes a current load detection unit 151 (an example of a second sensor) that detects the moving speed of the self-propelled mobile body 1. When the detected moving speed exceeds the upper limit value, the control unit 14 causes the servo motor 15 to generate a braking force so that the moving speed becomes equal to or lower than the upper limit value.

[0066] Thereby, the operator can move the self-propelled mobile body 1 safely. For example, when the operator is pushing the self-propelled mobile body 1 down a slope, there is a risk that the speed will increase too much, or when the operator pushes the self-propelled mobile body 1 too hard, there is a risk that the speed will increase too much. However, the self-propelled mobile body 1 enables a safer operation by providing a speed limit.

[0067] When the control unit 14 ends the temporary interruption of the execution of the operation plan by an operation by the operator, the control unit 14 causes the servo motor 15 to generate a driving force to move the self-propelled mobile body 1 to a position where the execution of the operation plan can be resumed. The end of the temporary interruption of the execution of the operation plan is, for example, the end of the assist mode described above.

[0068] As a result, even if the self-propelled mobile body 1 is temporarily moved by an operator, it returns to its original position by itself and resumes the operation plan, so that it can be operated with less labor.

[0069] Further, the self-propelled mobile body 1 further includes a coupling mechanism 3 for coupling an attached carriage 4 having wheels 6. In a state where the self-propelled mobile body 1 and the attached carriage 4 are coupled by the coupling mechanism 3, pressure sensors 23 to 26 are provided at positions for detecting pressure caused by an operator pulling or pressing the self-propelled mobile body 1 or the attached carriage 4, as an example of a first sensor for detecting the pulling or pressing.

[0070] As a result, the self-propelled mobile body 1 can detect an operation of pulling or pressing by an operator with a simple configuration without using a special sensor or complicated processing.

[0071] Further, a current load detection unit 151 for detecting the moving speed of the self-propelled mobile body 1 is, for example, a load sensor of the servo motor 15 or a current sensor for detecting a current change of the servo motor 15.

[0072] As a result, the self-propelled mobile body 1 can accurately detect the moving speed of the self-propelled mobile body 1 without adding a special configuration.

[0073] In the above-described embodiment, the displacement (travel distance) and travel direction of the self-propelled mobile body 1 during the assist mode are recorded, and a method for the self-propelled mobile body 1 to return to its original position after the assist mode ends using this record is shown. However, the self-propelled mobile body 1 may return to its original position using other methods. For example, the position information of the point where the assist mode is entered may be stored, and the self-propelled mobile body may travel based on the map data stored in the map storage unit 12 and return to its original position. Also, a normal line may be virtually drawn from the current position of the self-propelled mobile body 1 to the planned route. If there are no obstacles on the normal line, the mobile body may move along the normal line and resume the operation plan when it reaches the planned route. By doing so, the self-propelled mobile body 1 can move linearly, enabling energy savings and time savings. Also, odometry for estimating the self-position of the self-propelled mobile body 1 from the rotation angle of the wheels 2 may be used to return to the original position or route.

[0074] In the above-described embodiment, the pressure sensors 23 to 26 for detecting that the self-propelled mobile body 1 has been pulled or pressed are arranged near the connection mechanism 3 between the self-propelled mobile body 1 and the attached carriage 4. However, it is also possible to arrange them near the handle 7 of the attached carriage 4. For example, when the operator grips the handle 7 and attempts to move the self-propelled mobile body 1 forward, backward, or turn it, a force is applied to the handle 7. The self-propelled mobile body 1 may detect the force applied to the handle 7 with a pressure sensor and detect whether it is forward, backward, or turning based on the detected value. In this way, by arranging the pressure sensor near the handle 7, it is also possible to move the self-propelled mobile body 1 with less labor in accordance with the operator's intention.

[0075] Also, in this embodiment, the description has been made with the configuration in which the attached carriage 4 and the self-propelled mobile body 1 can be connected and detached. However, the present invention is not limited to this configuration. For example, if a handle 7 is provided on the self-propelled mobile body 1 itself and the above-described pressure sensor is provided here, the same assist mode can be realized with the self-propelled mobile body 1 alone.

[0076] Incidentally, the above-described self-propelled mobile body 1 has a computer system inside. Then, a program for realizing the functions of each component provided in the above-described self-propelled mobile body 1 is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read into the computer system and executed, so that the processing in each component provided in the above-described self-propelled mobile body 1 may be performed. Here, "reading the program recorded on the recording medium into the computer system and executing it" includes installing the program in the computer system. The "computer system" as used herein is assumed to include hardware such as an OS and peripheral devices. Further, the "computer system" may include a plurality of computer devices connected via a network including a communication line such as the Internet, WAN, LAN, or dedicated line. Also, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, magneto-optical disk, ROM, CD-ROM, or a storage device such as a hard disk built into the computer system. Thus, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

[0077] Further, the recording medium also includes an internal or external recording medium provided so as to be accessible from a distribution server for distributing the program. Note that the program may be divided into a plurality of parts, downloaded at different timings, and then combined in each component provided in the self-propelled mobile body 1, or the distribution servers for distributing the divided programs may be different. Furthermore, the "computer-readable recording medium" also includes a volatile memory (RAM) inside a computer system that becomes a server or a client when a program is transmitted via a network and holds the program for a certain period of time. Also, the above program may be for realizing a part of the above-described functions. Further, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

[0078] Furthermore, some or all of the functions provided in the self-propelled mobile body 1 in the above-described embodiments may be realized as an integrated circuit such as an LSI (Large Scale Integration). Each function may be individually processed by a processor, or some or all of them may be integrated and processed by a processor. In addition, the method of integrating into a circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. Also, when a circuit integration technology that replaces an LSI appears due to the progress of semiconductor technology, an integrated circuit using such technology may be used.

[0079] As described above, the embodiments of the present disclosure have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the embodiments of the present disclosure can be appropriately modified or omitted.

Description of Reference Numerals

[0080] 1 Self-propelled mobile body, 2 Wheels, 3 Linkage mechanism, 4 Attached cart, 5 Support leg, 6 Wheels, 7 Handle, 11 Operation plan storage unit, 12 Map storage unit, 13 Sensor, 14 Control unit, 15 Servo motor, 16 Front panel, 17 Main body, 18 3D camera, 19 LiDAR, 21, 22 Notch, 23, 24, 25, 26 Pressure sensor, 31, 32 Latch, 33, 34 Locking plate, 151 Current load detection unit, 100 Operation record file, 50 Control server, SYS Self-propelled mobile body system, NW Wireless network

Claims

1. A self-propelled mobile body comprising a motor that drives wheels and a control unit that controls the motor based on an operation plan stored in a storage unit to drive the wheels, a connecting mechanism for connecting an attached carriage, a first sensor provided in the connecting mechanism, the first sensor detecting that an operator has pulled or pushed the self-propelled mobile body in a state where the self-propelled mobile body and the attached carriage are connected by the connecting mechanism, and comprising, wherein the control unit, after receiving an operation for temporarily interrupting the execution of the operation plan by the operator, when traction or pressing by the operator is detected by the first sensor, generates a driving force or a braking force in the direction of traction or pressing by the operator in the motor, a self-propelled mobile body.

2. further comprising a second sensor for detecting the moving speed of the self-propelled mobile body, wherein the control unit generates a braking force in the motor so that the moving speed becomes equal to or lower than the upper limit value when the moving speed detected using the second sensor exceeds the upper limit value, The self-propelled mobile body according to claim 1.

3. wherein the control unit, when ending the temporary interruption of the execution of the operation plan by an operation by the operator, generates a driving force in the motor to move the self-propelled mobile body to a position where the execution of the operation plan can be resumed, The self-propelled mobile body according to claim 1 or claim 2.

4. wherein the motor is a servo motor, and the second sensor is a load sensor of the servo motor, The self-propelled mobile body according to claim 2.

5. wherein the motor is a servo motor, and the second sensor is a sensor that detects a change in current of the servo motor, The self-propelled mobile body according to claim 2.

6. A control method in a self-propelled mobile body comprising a motor that drives wheels, a connecting mechanism for connecting an attached carriage, and a control unit that controls the motor based on an operation plan stored in a storage unit to drive the wheels, a step of detecting, by a first sensor provided in the connecting mechanism, that an operator has pulled or pushed the self-propelled mobile body in a state where the self-propelled mobile body and the attached carriage are connected by the connecting mechanism, a step of generating, by the control unit, a driving force or a braking force in the direction of traction or pressing by the operator in the motor when traction or pressing by the operator is detected by the first sensor after the control unit has received an operation for temporarily interrupting the execution of the operation plan by the operator, A control method including

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