Autonomous mobile vehicle, method for controlling an autonomous mobile vehicle, and control program for an autonomous mobile vehicle

Abstract

The autonomous mobile devices are controlled in a way that allows humans to easily resolve situations where the autonomous devices interfere with human activity. [Solution] The autonomous mobile device comprises an electric motor and wheels driven by the electric motor, The system includes a processing circuit for controlling the electric motor. When an external force is applied to the autonomous mobile body, the processing circuit stops supplying power to the electric motor so that the wheels move due to the external force.

Description

Technical Field

[0001] The present disclosure relates to an autonomous mobile body, a method for controlling the autonomous mobile body, and a control program for the autonomous mobile body.

Background Art

[0002] Patent Document 1 discloses a system that changes the moving direction of a robot or reduces the moving speed of the robot to mitigate a collision when a peripheral object contacts the robot arm during the movement of the robot.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Patent Document 1 does not disclose any countermeasures when the robot gets in the way of a human.

[0005] One aspect of the present disclosure aims to provide an autonomous mobile body such that a human can easily eliminate a situation where the autonomous mobile body gets in the way of the human.

Means for Solving the Problems

[0006] An autonomous mobile body according to one aspect of the present disclosure includes an electric motor, wheels driven by the electric motor, and a processing circuit that controls the electric motor. When an external force is applied to the autonomous mobile body, the processing circuit stops supplying power to the electric motor so that the wheels move by the external force.

[0007] A control method for an autonomous mobile body according to one aspect of the present disclosure is a control method for an autonomous mobile body comprising wheels and an electric motor that drives the wheels, wherein when an external force is applied to the autonomous mobile body, the power supply to the electric motor is stopped so that the wheels move in response to the external force applied to the autonomous mobile body.

[0008] A control program for an autonomous mobile body according to one aspect of the present disclosure causes a processor to execute the control method. The program may be stored in a computer-readable, non-temporary, and tangible storage medium. [Effects of the Invention]

[0009] According to one aspect of this disclosure, situations in which an autonomous mobile vehicle equipped with wheels interferes with humans can be easily resolved by humans. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a side view of an autonomous mobile body according to an embodiment of this model. [Figure 2] Figure 2 is a block diagram of the autonomous mobile unit shown in Figure 1. [Figure 3] Figure 3 is a block diagram of the drive power system of the autonomous mobile unit shown in Figure 2. [Figure 4] Figure 4 is a flowchart of the control of the autonomous mobile unit shown in Figure 2. [Modes for carrying out the invention]

[0011] Embodiments will be described below with reference to the drawings.

[0012] Figure 1 is a side view of an autonomous mobile body according to an embodiment. As shown in Figure 1, the autonomous mobile body 1 comprises a plurality of wheels 11 and a body 12 supported by the plurality of wheels 11. The body 12 includes a cargo bed 13 for carrying cargo. The autonomous mobile body 1 includes an autonomous mobile robot that autonomously travels on the ground while detecting its own position on a map. The autonomous mobile body 1 includes a robot that performs the task of transporting cargo placed on the cargo bed 13 to a destination. The autonomous mobile body 1 may also include a robot that performs security tasks by monitoring its surroundings while traveling. The autonomous mobile body 1 communicates with a server 2 via a communication network. Humans 3 may also be present in the activity area of ​​the autonomous mobile body 1.

[0013] The autonomous mobile vehicle 1 is equipped with, for example, the same number of electric motors 22 as the number of wheels 11. Each wheel 11 is coupled to an electric motor 22 that can operate independently of each other. The electric motors 22 directly drive the corresponding wheel 11. The autonomous mobile vehicle 1 can change its direction of travel by, for example, using Mecanum wheels for each wheel 11. In this embodiment, one electric motor 22 drives one wheel 11, but a configuration in which one electric motor 22 drives two or more wheels 11 is also possible. The configuration of the wheels 11 of the autonomous mobile vehicle 1 is not particularly limited, and omni wheels or general wheels may be used instead of Mecanum wheels. The wheel 11 includes one or more drive wheels and one or more driven wheels, and electric motors 22 may be coupled to one or more drive wheels. When general wheels are used as wheels 11, the autonomous mobile vehicle 1 is equipped with a steering mechanism that steers at least one wheel 11.

[0014] The wheels 11 are connected to the body 12 via a connecting structure 14. The connecting structure 14 includes links. The connecting structure 14 may further include a suspension. External forces applied to the body 12 are transmitted to the wheels 11 via the connecting structure 14. The autonomous mobile unit 1 is equipped with a bumper 15 positioned to cover the lower outer surface of the body 12. An emergency stop button 16, operated by a human, is located on the upper part of the body 12. When the emergency stop button 16 is operated, the emergency stop switch 30 is activated in conjunction with the emergency stop button 16. The emergency stop button 16 may also be a power button. The emergency stop button 16 is not limited to a button, but may be any interface operated by a human to activate the emergency stop switch 30.

[0015] Figure 2 is a block diagram of the autonomous mobile unit 1 shown in Figure 1. As shown in Figure 2, the autonomous mobile unit 1 includes a controller 21. The controller 21 includes a processor 41, system memory 42, and storage memory 43. The processor 41 may include a CPU. The system memory 42 may include volatile memory. The storage memory 43 may include non-volatile memory. The storage memory 43 includes a hard disk, flash memory, or a combination thereof. The storage memory 43 downloads map data of the autonomous mobile unit 1's activity area from the server 2 and stores that map data. The storage memory 43 stores the control program P. An example of a processing circuit 40 is a configuration in which the processor 41 executes the control program P read from the storage memory 43 into the system memory 42.

[0016] The autonomous mobile unit 1 comprises an electric motor 22, an inverter 23, and a battery 24. The electric motor 22 includes a traction motor for driving the wheels 11. The number of electric motors 22 is equal to the number of wheels 11, and each electric motor 22 independently controls the corresponding wheel 11. However, the number of electric motors 22 may be less than the number of wheels 11, and one electric motor 22 may drive multiple wheels 11. The electric motor 22 is electrically connected to the battery 24 via the inverter 23. The inverter 23 converts the DC power supplied from the battery 24 into AC power and supplies power to the electric motor 22. The inverter 23 is controlled by a processing circuit 40 of the controller 21. The processing circuit 40 controls the electric motor 22 via the inverter 23. The wheels 11 can rotate by external force when the power supply to the electric motor 22 is stopped. The state in which the power supply to the electric motor 22 is stopped includes the state in which the electric motor 22 is not controlled by the inverter 23.

[0017] The autonomous mobile unit 1 is equipped with a positioning sensor 25, a touch panel display 26, a speaker 27, a warning light 28, a communication interface 29, an emergency stop switch 30, a current sensor 31, an IMU (inertial measurement unit) 32, a first pressure sensor 33, a strain sensor 34, and a second pressure sensor 35.

[0018] Various sensors can be used as the positioning sensor 25, as long as they can detect the position of the autonomous mobile body 1. In this embodiment, the positioning sensor 25 includes a distance measuring sensor. The positioning sensor 25 detects the shape of objects around the autonomous mobile body 1 in three dimensions by measuring the distance around the autonomous mobile body 1 in three dimensions. The positioning sensor 25 detects the position data of the outer surface of obstacles around the autonomous mobile body 1 by receiving reflected waves from objects around the autonomous mobile body 1. The positioning sensor 25 includes, for example, a LiDAR (Light Detection and Ranging) sensor, an infrared distance measuring sensor, a millimeter-wave radar, or a depth sensing camera.

[0019] The processing circuit 40 identifies the position of the autonomous mobile body 1 on the map data by matching the shape of the surrounding objects detected by the positioning sensor 25 with the shape of the map data described above. The function of identifying the position of the autonomous mobile body 1 is realized by the combination of the positioning sensor 25 and the software that matches the shape of the object detected by the positioning sensor 25 with the map data.

[0020] As the positioning sensor 25 of the autonomous mobile body 1, a satellite positioning sensor such as a GPS sensor may be used instead of the distance measuring sensor. Based on the intensity of each radio wave received by the autonomous mobile body 1 from a plurality of wireless access points installed in the activity area of the autonomous mobile body 1, the processing circuit 40 calculates the distance from each wireless access point to the autonomous mobile body 1, whereby the processing circuit 40 may position the autonomous mobile body 1. Instead of using the radio waves received from a plurality of wireless access points for positioning, the processing circuit 40 may position the autonomous mobile body 1 using sound waves, light or magnetism received from a plurality of locators installed in the activity area. When the autonomous mobile body 1 travels by remote control, the positioning function may be omitted.

[0021] The touch panel display 26 is an example of a user interface. The touch panel display 26 can also function as a notifier that outputs a visual warning display to the outside of the autonomous mobile body 1 as a notification. The touch panel display 26 functions as both a user input interface and a user output interface. The user input interface may include at least one of a keyboard, a mouse, a smartphone or a tablet terminal capable of communicating with the autonomous mobile body 1. The user output interface may include a non-touch panel type display.

[0022] Speaker 27 outputs sound. Speaker 27 also functions as a notification device that outputs a warning sound to the outside of the autonomous mobile robot 1 as a notification. Warning lamp 28 outputs light. Warning lamp 28 includes at least one of a lamp and an LED. Warning lamp 28 functions as a notification device that outputs warning light to the outside of the autonomous mobile robot 1 as a notification. When the touch panel display 26 performs notification, warning lamp 28 may be omitted.

[0023] Communication interface 29 includes a wireless communication device for wirelessly connecting to a communication network connected to server 2. Communication interface 29 may include a wireless communication device for mobile communication such as LTE communication and local 5G, or may include a wireless communication device for Wi-Fi communication.

[0024] Emergency stop switch 30 is switchable between two states including a first state and a second state. Emergency stop switch 30 switches in conjunction with emergency stop button 16 when emergency stop button 16 is pressed by a person. When emergency stop switch 30 is in the first state, power supply from battery 24 to electric motor 22 is permitted. When emergency stop switch 30 is in the second state, power supply from battery 24 to electric motor 22 is cut off. Emergency stop switch 30 includes, for example, a contact switch. Emergency stop switch 30 may be a power switch.

[0025] Processing circuit 40 controls electric motor 22 via inverter 23 according to control program P based on information input from at least one of positioning sensor 25, touch panel display 26, communication interface 29, etc., to autonomously drive autonomous mobile robot 1.

[0026] Current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35 may function as sensors for detecting that an external force has been applied to autonomous mobile robot 1.

[0027] The current sensor 31 detects the current flowing between the inverter 23 and the electric motor 22. When an external force is applied to the autonomous mobile body 1 while it is autonomously moving, an electromotive force is generated in the electric motor 22 to which the external force is transmitted, and the waveform of the current changes to an unintended waveform. Therefore, by monitoring the detection signal from the current sensor 31, the processing circuit 40 can determine whether or not an external force has been applied to the autonomous mobile body 1.

[0028] The IMU32 is connected to the body 12. The IMU32 includes a three-axis gyroscope and a three-directional accelerometer. Instead of the IMU32, a simple accelerometer may be used. The IMU32 can detect the acceleration occurring in the body 12 when an external force is applied, and the change in attitude occurring in the body 12 when an external force is applied.

[0029] The first pressure sensor 33 is sandwiched between the bumper 15 and the body 12. The first pressure sensor 33 can detect the pressure caused by the displacement of the bumper 15 when an external force is applied. The strain sensor 34 is attached to the coupling structure 14. The strain sensor 34 can detect the strain generated in the coupling structure 14 when an external force is applied to the wheel 11 or the body 12. The second pressure sensor 35 is located inside the coupling structure 14, between the body 12 and the coupling structure 14, or between the wheel 11 and the coupling structure 14. The second pressure sensor 35 can detect the pressure generated in the coupling structure 14 when an external force is applied to the wheel 11 or the body 12.

[0030] The current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35 are merely illustrative examples. The autonomous mobile body 1 does not need to be equipped with all of the current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35. At least one of the current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35 is present, and the others may be omitted.

[0031] The processing circuit 40 may determine whether or not an external force has been applied to the autonomous mobile body 1 based on information other than the information obtained from the current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35. For example, the processing circuit 40 estimates the current location of the autonomous mobile body 1 using an odometry method. The processing circuit 40 calculates the rotation amount of the electric motor 22 from the command value to the inverter 23 and estimates the rotation amount of the wheels 11 from the rotation amount of the electric motor 22. The processing circuit 40 determines the direction of movement of the autonomous mobile body 1 from the command value for the direction of movement of the autonomous mobile body 1. The processing circuit 40 estimates the current location of the autonomous mobile body 1 based on the rotation amount of each wheel 11 and the direction of movement of the autonomous mobile body 1. The processing circuit 40 identifies the position of the autonomous mobile body 1 on the map data by matching the shape of surrounding objects detected by the positioning sensor 25 with the shape of the map data.

[0032] The processing circuit 40 calculates the difference or distance between the current location of the autonomous mobile body 1 estimated using the odometry method and the current location of the autonomous mobile body 1 identified using the positioning sensor 25. If the autonomous mobile body 1 is pushed by a human 3 and the wheels 11 do not rotate properly, the difference between the current location of the autonomous mobile body 1 estimated using the odometry method and the current location of the autonomous mobile body 1 identified using the positioning sensor 25 becomes large. If the difference is greater than a predetermined value, the processing circuit 40 determines that an external force has been applied to the autonomous mobile body 1.

[0033] Figure 3 is a block diagram of the drive power system of the autonomous mobile unit 1 shown in Figure 2. As shown in Figure 3, the battery 24 is electrically connected to the inverter 23 via a first wire 51. The first wire 51 is provided with a relay 53 that can disconnect the first wire 51. The relay 53 operates in conjunction with the operation of the emergency stop switch 30. When the emergency stop switch 30 is in a first state, the relay 53 is in a closed state. When the autonomous mobile unit 1 is powered ON, the relay 53 is in a closed state. When the emergency stop switch 30 is in a second state, the relay 53 is in an open state. The inverter 23 is electrically connected to the electric motor 22 via a second wire 52 for three-phase AC. The inverter 23 includes a power circuit 54 connected to the electric motor 22. A current sensor 31 is provided, for example, on the second wire 52. The current sensor 31 may be provided in the internal circuit of the electric motor 22 or the inverter 23. The controller 21 is powered by the battery 24 when the autonomous mobile unit 1 is powered on. The controller 21 includes a step-down circuit that reduces the voltage of the power supplied by the battery 24.

[0034] If a person 3 pushes the autonomous mobile body 1 while it is moving autonomously, or if an obstacle hits the autonomous mobile body 1 while it is moving, an external force having a horizontal component acts on the autonomous mobile body 1. The processing circuit 40 of the controller 21 determines whether or not an external force has been applied to the autonomous mobile body 1 based on at least one detection signal from the current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35.

[0035] For example, the processing circuit 40 determines that an external force has been applied to the autonomous mobile body 1 when the waveform pattern of the current detected by the current sensor 31 differs from a predetermined waveform pattern. The processing circuit 40 may also determine that an external force has been applied to the autonomous mobile body 1 when the maximum value of the current detected by the current sensor 31 is greater than a threshold. For example, the processing circuit 40 may determine that an external force has been applied to the autonomous mobile body 1 when the horizontal acceleration detected by the IMU 32 exceeds a threshold. The processing circuit 40 may also determine that an external force has been applied to the autonomous mobile body 1 when the angular velocity relative to the vertical detected by the IMU 32 exceeds a threshold. The processing circuit 40 may also determine that an external force has been applied to the autonomous mobile body 1 when the pressure detected by the first pressure sensor 33 exceeds a threshold. The processing circuit 40 may also determine that an external force has been applied to the autonomous mobile body 1 when the strain detected by the strain sensor 34 exceeds a threshold. The processing circuit 40 may determine that an external force has been applied to the autonomous mobile body 1 when the pressure detected by the second pressure sensor 35 exceeds a threshold.

[0036] When the processing circuit 40 determines that an external force has been applied to the autonomous mobile body 1, it controls the inverter 23 to stop supplying power to the electric motor 22. When the power supply to the electric motor 22 is stopped, the wheels 11 can move due to the external force applied to the autonomous mobile body 1.

[0037] Figure 4 is a flowchart of the control of the autonomous mobile unit 1 in Figure 2. The control of the autonomous mobile unit 1 will be explained below in accordance with the flowchart in Figure 4, with reference to Figures 1 to 3 as appropriate. In step S1, the processing circuit 40 of the autonomous mobile unit 1 controls the electric motor 22 according to the travel plan and makes the autonomous mobile unit 1 travel autonomously to the destination. The state in which the autonomous mobile unit 1 travels autonomously is called the normal state. In step S2, the processing circuit 40 determines whether or not an external force has been applied to the autonomous mobile unit 1 based on at least one detection signal from the current sensor 31, IMU 32, first pressure sensor 33, strain sensor 34, and second pressure sensor 35.

[0038] If it is determined in step S2 that no external force is being applied to the autonomous mobile unit 1, the process proceeds to step S1, and the processing circuit 40 maintains the autonomous mobile unit 1 in its normal state. If it is determined in step S2 that an external force has been applied to the autonomous mobile unit 1, in step S3, the processing circuit 40 stops the inverter 23 from supplying power to the electric motor 22. The state in which the processing circuit 40 stops the inverter 23 from supplying power to the electric motor 22 is called the temporary state. In the temporary state, the power supply from the battery 24 to the processing circuit 40 is not stopped. In step S3, the processing circuit 40 transitions the autonomous mobile unit 1 from its normal state to the temporary state. By transitioning the autonomous mobile unit 1 from its normal state to the temporary state, the autonomous mobile unit 1 can be moved by an external force.

[0039] In step S3, the processing circuit 40 prevents current from being generated in the power circuit 54 due to the back electromotive force caused by the forced rotation of the electric motor 22 to which the external force is transmitted, by causing the inverter 23 to open the power circuit 54. Thus, the power circuit 54 is protected, and the wheels 11 rotate smoothly, facilitating the movement of the autonomous mobile body 1 by the external force. The power circuit 54 includes, for example, a relay or a switching element. In step S3, the processing circuit 40 opens the relay or switching element included in the power circuit 54.

[0040] Next, the processing circuit 40 determines whether predetermined conditions for returning the autonomous mobile unit 1 to its normal state and resuming autonomous driving have been met in the temporary state of the autonomous mobile unit 1. In step S4, the processing circuit 40 determines whether the first condition, that the state in which an external force is applied to the autonomous mobile unit 1 has been resolved, has been met. In other words, in step S4, the processing circuit 40 determines whether or not an external force is no longer applied to the autonomous mobile unit 1. If it is determined in step S4 that the first condition has not been met, the process proceeds to step S3, and the processing circuit 40 maintains the temporary state of the autonomous mobile unit 1.

[0041] If it is determined in step S4 that the first condition has been met, then in step S5, the processing circuit 40 determines whether the second condition has been met, which is that a predetermined amount of time has elapsed since the state in which an external force was applied to the autonomous mobile body 1 was resolved. In other words, in step S5, the processing circuit 40 determines whether the state in which no external force was applied to the autonomous mobile body 1 continued for a predetermined period of time. If it is determined in step S5 that the second condition has not been met, the process proceeds to step S3, and the processing circuit 40 maintains the temporary state of the autonomous mobile body 1.

[0042] If it is determined in step S5 that the second condition has been met, then in step S6, the processing circuit 40 determines whether the third condition has been met, which is that the situation around the autonomous mobile body 1 has reached a predetermined state. The predetermined state includes, for example, a situation in which there are no obstacles within a predetermined range relative to the autonomous mobile body 1. The obstacle may be a person or an object. The processing circuit 40 may determine the presence or absence of an obstacle based on the detection signal from the positioning sensor 25. If it is determined in step S6 that the third condition has not been met, the process proceeds to step S3, and the processing circuit 40 maintains the temporary state of the autonomous mobile body 1.

[0043] In step S6, if it is determined that the third condition has been met, in step S7, the processing circuit 40 causes the alarm to output a notification using at least one of sound and light to the outside of the autonomous mobile unit 1. For example, the processing circuit 40 causes the speaker 27 to output a sound indicating the start of movement, and also causes the warning light 28 to light up or flash. The notification from the alarm allows people in the vicinity to be notified that the autonomous mobile unit 1 has returned from a temporary state to a normal state and will resume autonomous driving.

[0044] In step S8, the processing circuit 40 controls the electric motor 22 via the inverter 23 and resumes autonomous driving according to the movement plan. By the processing circuit 40 executing the flowchart shown in Figure 4, the autonomous mobile body 1 spontaneously resumes movement without any special work required after an external force is applied to it, thus eliminating the need for user intervention.

[0045] The first, second, and third conditions are given as examples of predetermined conditions for resuming autonomous driving, but at least one of the second and third conditions may be omitted. The predetermined conditions may include only the first and second conditions. The predetermined conditions may include only the first and third conditions. The order in which the first, second, and third conditions are determined is not particularly limited.

[0046] In the flowchart of Figure 4, step S7 may be omitted. If step S7 is omitted, the processing load on the processing circuit 40 is reduced. The processing circuit 40 may omit step S7 if it determines, based on the detection signal from the positioning sensor 25, that no objects are detected in the predetermined surroundings of the autonomous mobile body 1.

[0047] The autonomous mobile unit 1 may be equipped with a second relay capable of disconnecting the second wire 52 between the inverter 23 and the motor 22. In step S3 of the flowchart in Figure 4, the processing circuit 40 may open the second relay to prevent current from being generated in the power circuit 54 due to the back electromotive force caused by the forced rotation of the electric motor 22 to which the external force is transmitted.

[0048] According to the configuration described above, when a person pushes the autonomous mobile unit 1 with their hand in the direction they want it to move, applying an external force, the power supply to the electric motor 22 in the autonomous mobile unit 1 stops, and the wheels 11 move due to the external force. Therefore, by having a person push the autonomous mobile unit 1 to move it, situations where the autonomous mobile unit 1 gets in the way of the person can be easily resolved.

[0049] As described above, the embodiments have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to the embodiments described above and can be applied to embodiments that have been modified, replaced, added to, or omitted as appropriate. Furthermore, it is possible to combine the components described in the embodiments to create new embodiments. For example, some components or methods in one embodiment may be applied to other embodiments, and some components in an embodiment can be separated from other components in that embodiment and extracted as appropriate. Among the components described in the attached drawings and detailed description are not only components that are essential for solving the problem, but also components that are not essential for solving the problem, in order to illustrate the technology.

[0050] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, dedicated processors, integrated circuits, ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. A processor is considered a processing circuit or circuit because it includes transistors and other circuits. In this disclosure, a circuit, unit, or means is hardware that performs the enumerated functions, or hardware programmed to perform the enumerated functions. The hardware may be hardware disclosed herein, or other known hardware that is programmed or configured to perform the enumerated functions. If the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0051] [Aspect] The embodiments described above are specific examples of the following embodiments.

[0052] (Aspect 1) It is an autonomous mobile vehicle, Electric motor and, The wheels are driven by the aforementioned electric motor, The system includes a processing circuit for controlling the aforementioned electric motor, The processing circuit, when an external force is applied to the autonomous mobile body, stops supplying power to the electric motor so that the wheels move due to the external force.

[0053] According to the configuration of Embodiment 1, when an external force is applied to the autonomous mobile body, the power supply to the electric motor in the autonomous mobile body stops, and the wheels move due to the external force. Therefore, a person can easily resolve a situation where the wheeled autonomous mobile body is getting in their way.

[0054] (Aspect 2) The autonomous mobile body according to embodiment 1, wherein the processing circuit opens the power circuit connected to the electric motor when the external force is applied to the autonomous mobile body.

[0055] According to the configuration of Embodiment 2, since no unnecessary current is generated in the electric motor and power circuit, the power circuit can be protected, and the wheels can rotate smoothly, facilitating the movement of the autonomous mobile body by external forces.

[0056] (Aspect 3) The autonomous mobile body according to embodiment 1 or 2, wherein the processing circuit determines that the external force has been applied to the autonomous mobile body based on the electromotive force generated in the electric motor.

[0057] According to the configuration of Embodiment 3, it is easier to detect when a user intentionally applies an external force to move the autonomous mobile object.

[0058] (Aspect 4) The system further includes a sensor that detects when the aforementioned external force is applied to the autonomous mobile body, The processing circuit determines, based on the detection signal of the sensor, that the external force has been applied to the autonomous mobile body, according to any one of embodiments 1 to 3.

[0059] According to the configuration of Embodiment 4, it is easier to detect that an external force has been applied to the autonomous mobile body before the autonomous mobile body moves due to the external force.

[0060] (Appendix 5) The body is supported by the aforementioned wheels, The system further comprises a connecting structure for connecting the wheels to the body, The autonomous mobile body according to embodiment 4, wherein the sensor includes at least one sensor selected from the group consisting of an acceleration sensor provided on the body, a first pressure sensor provided on the body, a strain sensor for detecting strain occurring in the connecting structure, and a second pressure sensor for detecting pressure occurring in the connecting structure.

[0061] According to the configuration of Embodiment 5, it is possible to reliably detect when an external force is applied to an autonomous mobile body.

[0062] (Aspect 6) The aforementioned processing circuit is Based on the amount of rotation of the wheels and the direction of movement of the autonomous mobile body, position estimation is performed to estimate the current location of the autonomous mobile body. Location information indicating the current location of the autonomous mobile body is obtained by a method different from the aforementioned location estimation method. An autonomous mobile body according to any one of embodiments 1 to 5, which determines that the external force has been applied to the autonomous mobile body based on the difference between the estimated current location and the acquired current location.

[0063] According to the configuration of embodiment 6, it is possible to determine that an external force has been applied to the autonomous mobile body without directly detecting the external force applied to the autonomous mobile body.

[0064] (Aspect 7) The aforementioned processing circuit is In the normal state in which the electric motor is controlled according to the movement plan of the autonomous mobile body, when an external force is applied to the autonomous mobile body, the system transitions from the normal state to a temporary state in which the supply of power to the electric motor is stopped. An autonomous mobile body according to any one of embodiments 1 to 6, wherein the electric motor is controlled to resume movement according to the movement plan when predetermined conditions are met.

[0065] According to the configuration of Embodiment 7, the autonomous mobile unit spontaneously resumes movement without requiring any special work after an external force is applied to it, thus saving the user effort.

[0066] (Pattern 8) The autonomous mobile body according to embodiment 7, wherein the predetermined conditions include a first condition that the state in which the external force is applied to the autonomous mobile body has been resolved.

[0067] According to the configuration of Embodiment 8, when the external force applied to the autonomous mobile unit ceases, the autonomous mobile unit spontaneously resumes movement, thus reducing the user's effort.

[0068] (Aspect 9) The autonomous mobile body according to embodiment 8, wherein the predetermined conditions further include a second condition that a predetermined time has elapsed after the first condition that the state in which the external force is applied to the autonomous mobile body has been resolved is met.

[0069] According to the configuration of embodiment 9, the autonomous mobile body can take a preparation period to resume movement after the external force applied to it has ceased.

[0070] (Aspect 10) The autonomous mobile body according to embodiment 8 or 9, wherein the predetermined conditions further include a third condition that the conditions around the autonomous mobile body become predetermined after the first condition that the state in which the external force is applied to the autonomous mobile body is resolved is met.

[0071] According to the configuration of embodiment 10, it is possible to confirm the conditions under which the autonomous mobile body can resume movement after the external force applied to it has ceased, such as the absence of people nearby.

[0072] (Aspect 11) The system further includes a notification device that outputs a notification using at least one of sound and light to the outside of the autonomous mobile body. The autonomous mobile body according to any one of embodiments 7 to 10, wherein the processing circuit causes the alarm to output the alarm after the predetermined conditions have been met and before resuming movement according to the movement plan.

[0073] According to the configuration of Embodiment 11, it is possible to inform people in the vicinity that the autonomous mobile body, which has been pushed by a human, is resuming movement according to its original movement plan.

[0074] (Aspect 12) A control method for an autonomous mobile body equipped with wheels and an electric motor that drives the wheels, A method for controlling an autonomous mobile body, wherein when an external force is applied to the autonomous mobile body, the power supply to the electric motor is stopped so that the wheels move in response to the external force applied to the autonomous mobile body.

[0075] According to the method of embodiment 12, when an external force is applied to the autonomous mobile body, the power supply to the electric motor in the autonomous mobile body stops, and the wheels move due to the external force. Therefore, a person can easily resolve a situation in which the wheeled autonomous mobile body is getting in their way.

[0076] (Aspect 13) A control program for an autonomous mobile body that causes a processor to execute the control method described in Embodiment 12. [Explanation of Symbols]

[0077] 1. Autonomous Mobile Unit 3 Human 11 wheels 12 Body 14 Connection structure 21 Controllers 22 Electric motor 23 Inverter 26 Touch panel display 27 speakers 28 Warning light 31 Current Sensor 32 IMU 33. First pressure sensor 34. Strain Sensor 35. Second pressure sensor 40 Processing Circuits 41 processors 54 Power circuit P Control Program

Claims

1. It is an autonomous mobile vehicle, Electric motor and, The wheels are driven by the aforementioned electric motor, The system includes a processing circuit for controlling the aforementioned electric motor, The processing circuit, when an external force is applied to the autonomous mobile body, stops supplying power to the electric motor so that the wheels move due to the external force.

2. The autonomous mobile body according to claim 1, wherein the processing circuit opens the power circuit connected to the electric motor when the external force is applied to the autonomous mobile body.

3. The autonomous mobile body according to claim 1, wherein the processing circuit determines that the external force has been applied to the autonomous mobile body based on the electromotive force generated in the electric motor.

4. The system further includes a sensor that detects when the aforementioned external force is applied to the autonomous mobile body, The processing circuit determines, based on the detection signal of the sensor, that the external force has been applied to the autonomous mobile body, according to claim 1.

5. The body is supported by the aforementioned wheels, The system further comprises a connecting structure for connecting the wheels to the body, The autonomous mobile body according to claim 4, wherein the sensor includes at least one sensor selected from the group consisting of an acceleration sensor provided on the body, a first pressure sensor provided on the body, a strain sensor for detecting strain occurring in the connecting structure, and a second pressure sensor for detecting pressure occurring in the connecting structure.

6. The aforementioned processing circuit is Based on the amount of rotation of the wheels and the direction of movement of the autonomous mobile body, position estimation is performed to estimate the current location of the autonomous mobile body. Location information indicating the current location of the autonomous mobile body is obtained by a method different from the aforementioned location estimation method. The autonomous mobile body according to claim 1, which determines that the external force has been applied to the autonomous mobile body based on the difference between the estimated current location and the acquired current location.

7. The aforementioned processing circuit is In the normal state in which the electric motor is controlled according to the movement plan of the autonomous mobile body, when an external force is applied to the autonomous mobile body, the system transitions from the normal state to a temporary state in which the supply of power to the electric motor is stopped. The autonomous mobile body according to any one of claims 1 to 6, wherein the electric motor is controlled to resume movement according to the movement plan when predetermined conditions are met.

8. The autonomous mobile body according to claim 7, wherein the predetermined conditions include a first condition that the state in which the external force is applied to the autonomous mobile body has been resolved.

9. The autonomous mobile body according to claim 8, wherein the predetermined conditions further include a second condition that a predetermined time has elapsed after the first condition that the state in which the external force is applied to the autonomous mobile body has been resolved is met.

10. The autonomous mobile body according to claim 8, wherein the predetermined conditions further include a third condition that the conditions around the autonomous mobile body become predetermined after the first condition that the state in which the external force is applied to the autonomous mobile body is resolved is met.

11. The system further includes a notification device that outputs a notification using at least one of sound and light to the outside of the autonomous mobile body. The autonomous mobile body according to claim 7, wherein the processing circuit causes the alarm to output the alarm after the predetermined conditions have been met and before resuming movement according to the movement plan.

12. A control method for an autonomous mobile body equipped with wheels and an electric motor that drives the wheels, A method for controlling an autonomous mobile body, wherein when an external force is applied to the autonomous mobile body, the power supply to the electric motor is stopped so that the wheels move in response to the external force applied to the autonomous mobile body.

13. A control program for an autonomous mobile body that causes a processor to execute the control method described in claim 12.

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