Moving body and control method for moving body

Abstract

To provide a moving body capable of stably guiding a user even in a traveling environment having a step, and a control method of the moving body.SOLUTION: The moving body 100 includes a drive wheel 21 that comes into contact with a floor surface F, a drive motor capable of rotating the drive wheel 21 around a first rotation axis O1 as a rotation center, a main body part 10 supported by the drive wheel 21 and moving with respect to the floor surface F when the drive wheel 21 rotates around a second rotation axis O2 as a rotation center, a passive wheel 31 that comes into contact with the floor surface F and is provided on a front side F R in a traveling direction D of the main body part 10 to support the main body part 10, and a handle 40 that can be gripped by a user, a notification unit 44 capable of notifying the user of predetermined information, and a control unit capable of controlling the notification unit 44 and the drive motor based on a detection result of contact between the passive wheel 31 and the step S of the floor surface F.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a mobile object and a method for controlling the mobile object. [Background technology]

[0002] Conventionally, mobile robots that assist users in walking have been known (for example, see Patent Document 1). The mobile robot assists the user in walking by, for example, moving along with the user who holds a handle provided on the mobile robot. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-70981 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the traveling environment of a mobile robot that guides a user, steps may hinder the traveling of the mobile robot.

[0005] In view of the above circumstances, the present invention aims to provide a moving body and a method for controlling a moving body that can stably guide a user even in a traveling environment with steps. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention proposes the following means. The mobile body of the present invention comprises a drive wheel that contacts the floor surface, a drive motor that can rotate the drive wheel around a first rotation axis as a center of rotation, a main body that is supported by the drive wheel and moves relative to the floor surface as the drive wheel rotates around the first rotation axis as a center of rotation, a passive wheel that contacts the floor surface and is provided in front of the main body in the direction of travel to support the main body, and rotates around a second rotation axis as the main body moves relative to the floor surface, a handle that can be held by a user, an alarm unit that can notify the user of specified information, a collision detection unit that can detect contact between the passive wheel and a step on the floor surface, and a control unit that controls the alarm unit and the drive motor based on the detection results of the collision detection unit.

[0007] The control method of a mobile body of the present invention is a control method of a mobile body that includes a drive wheel that contacts the floor surface, a drive motor that can rotate the drive wheel around a first rotation axis as a center of rotation, a main body that moves relative to the floor surface as the drive wheel rotates around the first rotation axis as a center of rotation, a passive wheel that is provided in front of the main body in the direction of travel and contacts the floor surface, and rotates around a second rotation axis as the main body moves relative to the floor surface, an alarm unit that can notify a user of predetermined information, and a collision detection unit that can detect contact between the passive wheel and a step on the floor surface, wherein when the collision detection unit detects contact between the passive wheel and the step, the alarm unit notifies the user that the passive wheel has contacted the step, and the torque of the drive motor is maintained constant. [Effects of the Invention]

[0008] According to the moving body and the method for controlling the moving body of the present invention, it is possible to provide a moving body and a method for controlling the moving body that can stably guide a user even in a traveling environment with steps. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a moving body according to an embodiment of the present invention. [Figure 2] FIG. 2 is a rear view of the moving body used by a user. [Figure 3] FIG. 2 is a functional block diagram showing the moving body. [Figure 4] FIG. 10 is a side view showing the moving body moving toward a step. [Figure 5] FIG. 10 is a plan view showing the moving body moving toward a step. [Figure 6] 10 is a flowchart showing an example of a control method for the moving object. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will be described with reference to the drawings.

[0011] FIG. 1 is a perspective view showing a moving body 100 according to this embodiment. FIG. 2 is a rear view of the vehicle 100 used by the user U. FIG.

[0012] In this embodiment, as shown in FIGS. 1 and 2, the vertical direction in the moving body 100 is defined as the "up-down direction V," the vertically upward direction as the "upward UP" in the vertical direction V, and the vertically downward direction as the "downward LO" in the vertical direction V. Furthermore, a direction perpendicular to the vertical direction V and the direction in which the moving body 100 mainly travels is defined as the "forward-backward direction (traveling direction) D," the direction in which the moving body 100 mainly travels is defined as the "forward FR" in the vertical direction D, and the opposite direction is defined as the "backward RR" in the vertical direction D. Furthermore, a direction perpendicular to the vertical direction V and the vertical direction D is defined as the "width direction W," one side in the width direction W is defined as the "rightward RT," and the opposite direction is defined as the "leftward LT" in the width direction W.

[0013] The moving body 100 includes a main body 10, a driving unit 20, a passive unit 30, a handle 40, a driving control unit 50, a step detection unit 60, and a control unit .

[0014] As shown in FIG. 2, a user U who uses the moving body 100 grips a handle 40 (described later) with his or her hands when using the moving body 100.

[0015] The moving body 100 is a walking support robot that guides the user U by autonomously traveling along with the user U. The user U can be guided to the destination by the moving body 100 by walking along with the movement of the moving body 100 as it moves to the destination.

[0016] The main body 10 is a base portion of the moving body 100. The main body 10 preferably has an outer shape that does not hinder the moving body 100 from assisting the user U in walking.

[0017] The drive unit 20 includes a drive wheel 21, a drive motor 22, and a collision detection unit 23.

[0018] As shown in FIGS. 1 and 2, the drive wheels 21 are provided at the rear RR and the lower LO of the main body 10 and support the main body 10.

[0019] The drive wheels 21 come into contact with a floor surface F. Here, the floor surface F refers to the floor surface or ground in the environment in which the moving body 100 travels. The floor surface F may be a floor surface inside a building, or may be an outdoor road surface or ground surface, etc.

[0020] In this embodiment, the drive wheel 21 is a wheel that is provided rotatable about a first rotation axis O1 that extends in the width direction W as the rotation center.

[0021] The drive unit 20 has two drive wheels 21 provided on the right side RT and the left side LT at the rear RR of the main body 10.

[0022] The drive motor 22 is an electric motor or the like that can rotate the drive wheels 21 around the first rotation axis O1.

[0023] In this embodiment, the mobile body 100 is a mobile robot with a drive system called a differential two-wheel type or an independent two-wheel drive type, and can rotate the two drive wheels 21 at different rotational speeds. That is, the drive motor 22 can rotate the two drive wheels 21 at different rotational speeds.

[0024] The drive unit 20 may have two drive motors 22 corresponding to the two drive wheels 21, respectively, or may be configured so that one drive motor 22 can rotate the two drive wheels 21.

[0025] When two drive wheels 21 are rotated by one drive motor 22, for example, the drive unit 20 rotates the two drive wheels 21 at different rotational speeds via a transmission mechanism having a plurality of gears or the like.

[0026] The collision detection unit 23 is a sensor capable of detecting that a passive wheel 31 (described later) has come into contact with an obstacle such as a step. In this embodiment, the collision detection unit 23 is a rotary encoder capable of measuring the amount of rotation of the drive motor 22.

[0027] The collision detection unit 23 is not limited to a rotary encoder, and may be an acceleration sensor, a gyro sensor, etc. Furthermore, the collision detection unit 23 may be provided in a location other than the drive unit 20 in the moving body 100.

[0028] The passive part 30 includes a passive wheel 31 .

[0029] 1, the driven wheels 31 are provided at the front FR and the bottom LO of the main body 10, and support the main body 10. The driven wheels 31 come into contact with the floor F.

[0030] In this embodiment, the driven wheel 31 is a wheel that is rotatable about a second rotation axis O2 as a rotation center. The driven wheel 31 is also rotatable about a third rotation axis O3 that extends in the up-down direction V as a rotation center.

[0031] The passive unit 30 has two passive wheels 31 provided on the right RT and left LT at the front FR of the main body 10.

[0032] The moving body 100 is supported by a driving unit 20 and a passive unit 30, and moves on a floor surface F by the driving motor 22 rotating the driving wheels 21 about a first rotation axis O1 as the center of rotation.

[0033] When the drive wheel 21 is rotated by the drive motor 22 around the first rotation axis O1, a frictional force is generated between the drive wheel 21 and the floor surface F, generating a propulsive force that moves the moving body 100 forward FR.

[0034] For example, when the moving body 100 travels forward FR, the second rotation axis O2, which is the rotation center of the driven wheel 31, extends in the width direction W. That is, the first rotation axis O1 and the second rotation axis O2 extend parallel to each other.

[0035] When the movable body 100 travels on a floor surface F, it travels mainly with the first rotation axis O1 and the second rotation axis O2 extending parallel to each other. That is, when the movable body 100 travels on the floor surface F, the drive wheels 21 and the passive wheels 31 travel on the floor surface F mainly facing in the same direction.

[0036] When the moving body 100 moves by the driving wheel 21 rotating around the first rotation axis O1 as the center of rotation, the passive wheel 31 passively rotates around the second rotation axis O2 as the center of rotation due to the frictional force generated between the driving wheel 21 and the floor surface F.

[0037] Furthermore, the driving unit 20 can change the traveling direction of the moving body 100 by rotating the two driving wheels 21 at different rotational speeds.

[0038] For example, when the rotational speed of the drive wheels 21 on the right RT is made higher than the rotational speed of the drive wheels 21 on the left LT, the moving body 100 turns left to the left LT.

[0039] Since the passive wheel 31 is rotatable around the third rotation axis O3, when the moving body 100 changes its direction of travel, the frictional force generated between the passive wheel 31 and the floor surface F causes the passive wheel 31 to rotate around the third rotation axis O3 as its center of rotation, and the second rotation axis O2 rotates in the horizontal direction perpendicular to the up-down direction V so as to be perpendicular to the direction of travel of the moving body 100.

[0040] In this way, the direction of travel of the moving body 100 is changed by rotating the two drive wheels 21 at different rotational speeds, and accordingly the passive wheel 31 passively rotates in a direction such that the second rotation axis O2 is perpendicular to the direction of travel of the moving body 100.

[0041] The handle 40 includes a support portion 41 , a grip portion 42 , and a notification portion 43 .

[0042] The support part 41 is a rod-shaped member extending upward UP from the main body part 10. As shown in Fig. 1, the handle 40 is provided on the right side RT of the main body part 10 and includes two support parts 41 arranged side by side at a predetermined interval in the front-rear direction D.

[0043] The grip portion 42 is a rod-shaped member extending in the front-rear direction D, and connects the upper ends UP of the two support portions 41 together.

[0044] The notification unit 43 is a device capable of notifying predetermined information to the user U. In this embodiment, the notification unit 43 is an actuator such as a vibration rotor provided inside the gripping unit .

[0045] For example, the notification unit 43 vibrates the grip unit 42 to notify predetermined information to the user U holding the grip unit 42. The information notified by the notification unit 43 will be described later.

[0046] The notification unit 43 may be any unit capable of notifying the user U of predetermined information, and may be a speaker that notifies information by voice, music, etc. The notification unit 43 may also be provided in a location other than the grip unit 42 on the moving object 100.

[0047] The handle 40 is not limited to the above-described configuration and shape as long as it has an outer shape that can be gripped by the user U.

[0048] When using the moving object 100, the user U is positioned on the right side RT of the moving object 100 and holds the grip part 42 with the left hand, as shown in Fig. 2. The moving object 100 guides the user U to the destination by moving with the user U holding the grip part 42.

[0049] The moving body 100 has rear drive wheels 21 rotated by drive motors 22 and front drive wheels 31 rotated passively due to friction with the floor surface F, so that when the moving body 100 turns to the right RT, contact between the moving body 100 and a user U positioned to the right RT of the moving body 100 can be prevented.

[0050] FIG. 3 is a functional block diagram showing the moving object 100. As shown in FIG.

[0051] The drive control unit 50 is a motor driver that can control the torque, rotation speed, number of rotations, rotation direction, etc. of the drive motor 22. The drive control unit 50 is provided inside the main body unit 10, for example.

[0052] 4 is a side view showing the moving body 100 moving toward a step S. As shown in FIG. 4, the step S is a portion that protrudes upward UP from the floor surface F on which the moving body 100 travels.

[0053] The step detection unit 60 is a sensor capable of detecting a step S in the forward direction FR of the moving body 100. The step detection unit 60 is, for example, a distance sensor capable of detecting the step S arranged at a distance from the moving body 100 in the traveling direction of the moving body 100, an imaging device such as a camera, or a LiDAR (Light Detection and Ranging).

[0054] In this embodiment, the step detector 60 is provided on the front FR of the main body 10. The step detector 60 may be provided on the right RT or left LT of the main body 10 as long as it is capable of detecting a step S.

[0055] The control unit 70 is a control device that can control a part or the whole of the moving body 100. The control unit 70 controls the notification unit 43 and the drive control unit 50, for example.

[0056] The control unit 70 is, for example, a programmable device (computer) equipped with a processor, a memory, a storage unit, etc. Each function of the control unit 70 is realized by one or more processors, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), executing a program stored in a program memory. However, all or part of these functions may be realized by hardware (e.g., circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). Furthermore, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), a RAM (Random Access Memory), etc.

[0057] The control unit 70 is provided, for example, inside the main body unit 10. The control unit 70 is capable of acquiring the detection results of the collision detection unit 23 and the step detection unit 60.

[0058] The control unit 70 controls the notification unit 43 and the drive control unit 50 based on the detection result of the collision detection unit 23. The control unit 70 also controls the drive control unit 50 based on the detection result of the step detection unit 60.

[0059] The control unit 70 controls the drive motor 22 by controlling the drive control unit 50. The control unit 70 may be configured to be able to directly control the drive motor 22 without going through the drive control unit 50.

[0060] FIG. 5 is a plan view showing the moving body 100 moving toward the step S. As shown in FIG.

[0061] When the moving body 100 advances toward the step S, the control unit 70 controls the rotation speed of the drive wheels 21 to change the approach angle θ of the moving body 100 with respect to the step S using the speed difference between the two drive wheels 21.

[0062] The approach angle θ of the moving body 100 with respect to the step S indicates the angle formed by the tangential direction Sa of the step S and the travelable direction RD of the drive wheels 21, as shown in FIG.

[0063] The tangential direction Sa of the step S is a direction perpendicular to the step S in the horizontal direction, and indicates, for example, the direction in which the step S is disposed relative to the drive wheel 21 in the horizontal direction.

[0064] The travelable direction RD of the drive wheels 21 is the direction in which the drive wheels 21, which rotate around the first rotation axis O1 as their rotation center, travel, and indicates a direction perpendicular to the first rotation axis O1 in the horizontal direction. The moving body 100 travels in the travelable direction RD of the drive wheels 21.

[0065] As described above, when the moving body 100 travels on the floor surface F, the drive wheels 21 and the passive wheels 31 mainly face in the same direction and travel on the floor surface F. Therefore, the travelable direction RD of the drive wheels 21 coincides with the direction in which the passive wheels 31 travel.

[0066] The driven wheel 31 is a front wheel provided at the front FR of the moving body 100. Therefore, the approach angle θ of the moving body 100 with respect to the step S is the approach angle of the driven wheel 31 with respect to the step S.

[0067] In the following description, as shown in FIG. 5, the drive wheel 21 disposed on the right RT will also be referred to as the "right drive wheel 21a," and the drive wheel 21 disposed on the left LT will also be referred to as the "left drive wheel 21b."

[0068] The moving body 100 illustrated in FIG. 5 can turn left LT by making the rotational speed of the right drive wheel 21a greater than the rotational speed of the left drive wheel 21b.

[0069] The moving body 100 illustrated in FIG. 5 can reduce the approach angle θ of the moving body 100 with respect to the step S by turning to the left LT, and can bring the approach angle θ closer to 0°.

[0070] It should be noted that if the moving object 100 turns further to the left LT after the approach angle θ of the moving object 100 relative to the step S becomes 0°, the approach angle θ of the moving object 100 relative to the step S increases from 0°.

[0071] Conversely, when the rotational speed of the left drive wheel 21b is made higher than the rotational speed of the right drive wheel 21a, the moving body 100 illustrated in FIG. 5 turns to the right RT, and the approach angle θ of the moving body 100 with respect to the step S becomes larger.

[0072] Next, a method for controlling the moving body 100 will be described. FIG. 6 is a flowchart showing an example of a method for controlling the moving object 100.

[0073] (Step S1) In step S1 (running start step), the moving body 100 performs a running motion with the user U gripping the grip portion .

[0074] For example, the grip unit 42 has a force sensor, buttons, etc. that allow the user U to input various operations. The user U can make the moving object 100 perform a predetermined operation by inputting an operation of applying force to the grip unit 42 in a predetermined direction or an operation of pressing a button on the grip unit 42.

[0075] When the running operation is performed, the moving body 100 runs on the floor surface F toward a predetermined destination. At this time, the moving body 100 may run on the floor surface F along a predetermined running route. The predetermined destination or running route is stored in advance in, for example, a memory unit or the like included in the control unit 70.

[0076] The control unit 70 rotates the drive wheels 21 with the drive motor 22 about the first rotation axis O1, causing the moving body 100 to travel on the floor surface F. The control unit 70 also controls the rotation speed of the drive wheels 21 to change the traveling direction of the moving body 100, causing the moving body 100 to travel toward the destination.

[0077] (Step S2) In the moving body 100 traveling on the floor surface F, the control unit 70 executes step S2 (step detection step).

[0078] In step S2, the control unit 70 acquires the detection result of the step detection unit 60. When there is a step S on the floor surface F in the traveling direction of the moving object 100, the step detection unit 60 detects the step S and transmits the detection result to the control unit 70.

[0079] When the step S is not detected in step S2, the control unit 70 proceeds to step S9, which will be described later.

[0080] When the step S is detected in step S2, the control unit 70 proceeds to step S3.

[0081] (Step S3) The control unit 70 performs step S3 (step approaching step) when the step S is detected. In step S3, the control unit 70 changes the traveling speed and posture of the moving body 100.

[0082] Specifically, the control unit 70 controls the drive motor 22 based on the detection result of the step detection unit 60.

[0083] At this time, the control unit 70 controls the drive motor 22 to reduce the traveling speed of the moving body 100 as the moving body 100 approaches the step S.

[0084] By slowing down the traveling speed of the moving body 100 entering the step S, it is possible to prevent the impact when the moving body 100 collides with the step S from being transmitted to the user U via the handle 40, and to prevent the moving body 100 from suddenly stopping.

[0085] Furthermore, the control unit 70 controls the drive motor 22 to reduce the approach angle θ of the moving body 100 with respect to the step S. It is preferable that the control unit 70 sets the approach angle θ to 0° and controls the drive motor 22 so that the moving body 100 approaches the step S perpendicularly.

[0086] For example, if the passive wheel 31 of the moving body 100 contacts the step S while being angled relative to the step S, the contact surface of the passive wheel 31 may not be in sufficient contact with the step S, and the moving body 100 may not be able to overcome the step S.

[0087] When the approach angle θ of the moving body 100 with respect to the step S is small, the moving body 100 can move over the step S stably because the contact surface of the driven wheel 31 can be brought into sufficient contact with the step S.

[0088] For example, the control unit 70 decreases the approach angle θ of the moving body 100 with respect to the step S as the moving body 100 approaches the step S.

[0089] When the moving body 100 approaches the step S, the traveling speed of the moving body 100 is reduced and the approach angle θ of the moving body 100 with respect to the step S is reduced, thereby allowing the moving body 100 to stably overcome the step S.

[0090] (Step S4) Next, the control unit 70 executes step S4 (a jam detection step).

[0091] When the moving body 100 enters the step S, the driven wheel 31 may not be able to climb over the step S and may get caught on the step S.

[0092] At this time, the control unit 70 determines whether the driven wheel 31 is caught on the step S based on the detection result of the collision detection unit 23.

[0093] When the moving body 100 enters the step S, the collision detection unit 23 detects that the driven wheel 31 has come into contact with the step S, and transmits the detection result to the control unit 70.

[0094] The control unit 70 determines whether the driven wheel 31 is caught on a step S based on the result obtained from the collision detection unit 23.

[0095] For example, when the driven wheel 31 is caught on a step S, the moving body 100 is prevented from traveling forward FR, and the rotation of the drive wheel 21 around the first rotation axis O1 is prevented.

[0096] At this time, if the collision detection unit 23 is a rotary encoder, the collision detection unit 23 detects contact between the driven wheel 31 and the step S by measuring the amount of rotation of the drive motor 22.

[0097] For example, based on the detection result of the collision detection unit 23, the control unit 70 determines that the driven wheel 31 is caught on a step S when the time during which the rotation of the drive wheel 21 is hindered is equal to or longer than a predetermined time.

[0098] When the control unit 70 determines in step S4 that the driven wheel 31 is not caught on the step S, the process proceeds to step S9.

[0099] When the control unit 70 determines in step S4 that the driven wheel 31 is caught on the step S, the process proceeds to step S5.

[0100] (Step S5) In step S5 (torque maintaining step), the control unit 70 changes the control method for the drive motor 22. Specifically, the control unit 70 changes the control method to one that maintains the torque of the drive motor 22 constant.

[0101] Before the control method of the drive motor 22 is changed in step S5, the control unit 70 uses PI control to control the drive motor 22. In step S5, the control unit 70 changes the control method of the drive motor 22 from PI control and maintains the torque of the drive motor 22 constant.

[0102] (Step S6) Next, the control unit 70 performs step S6 (notification step). In step S6, the control unit 70 transmits a signal to the notifying unit 43, causing the notifying unit 43 to notify predetermined information.

[0103] For example, if the notification unit 43 is an actuator provided in the grip portion 42, the notification unit 43 vibrates the grip portion 42 to notify the user U of predetermined information.

[0104] The user U holding the grip portion 42 recognizes that the passive wheel 31 is caught on the step S due to the vibration of the grip portion 42. In other words, the notification portion 43 notifies the user U that the passive wheel 31 is caught on the step S.

[0105] When the user U is notified by the notification unit 43 that the driven wheel 31 is caught on the step S, the user U lifts the driven wheel 31 off the floor surface F by pulling up the gripping unit 42 with his / her hand.

[0106] At this time, for example, the moving body 100 is in a state where the drive wheels 21 are in contact with the floor surface F and the driven wheels 31 are rotating so as to move upward UP with the drive wheels 21 as the fulcrum.

[0107] The passive wheel 31 floats upward UP, and the passive wheel 31 is released from being caught on the step S. With the passive wheel 31 no longer caught, the drive wheel 21 becomes able to rotate again, and the moving body 100 can resume traveling.

[0108] After the user U has raised the driven wheel 31 above the step S to a position UP, the user U stops lifting the gripping portion 42. At this time, the driven wheel 31 goes over the step S and touches the floor surface F again.

[0109] In this way, the driven wheel 31 overcomes the step S, and the moving body 100 is again ready to travel forward FR.

[0110] (Step S7) Next, the control unit 70 performs step S7 (crossing determination step). In step S7, the control unit 70 determines whether the driven wheel 31 has crossed the step S or not.

[0111] For example, the control unit 70 determines whether the passive wheel 31 has gone over the step S based on the detection result of the collision detection unit 23.

[0112] The moving body 100 may be provided with a passage detection unit that detects that the passive wheel 31 has passed over the step S and transmits the detection result to the control unit 70. In this case, the control unit 70 determines whether the passive wheel 31 has passed over the step S based on the detection result of the passage detection unit.

[0113] In this embodiment, the collision detection unit 23 functions as a passage detection unit. For example, if the collision detection unit 23 is a rotary encoder, the control unit 70 determines whether the passive wheel 31 has passed over the step S based on the amount of rotation of the drive motor 22 measured by the collision detection unit 23.

[0114] The control unit 70 may use the step detection unit 60 as a passage detection unit and determine whether the passive wheel 31 has passed over the step S based on the detection result of the step detection unit 60.

[0115] When the control unit 70 determines that the driven wheel 31 has not gone over the step S, the control unit 70 returns to step S6 and continues the operation of notifying the user U.

[0116] When the control unit 70 determines that the driven wheel 31 has gone over the step S, the process proceeds to step S8.

[0117] (Step S8) In step S8 (motor control change step), the control unit 70 changes the control method of the drive motor 22, which has been changed in step S5 to maintain constant torque, back to the control method used before step S5.

[0118] Specifically, in step S8, the control unit 70 changes the control method for the drive motor 22 to PI control.

[0119] A known method for controlling the drive motor that rotates the drive wheels of a mobile robot is to use PI control to control the difference between the target speed and the current speed. However, because I control uses an accumulated error value, the accumulated value can cause excessive motor output to be calculated when going over a step, which can lead to unstable rotation of the drive wheels.

[0120] The control unit 70 keeps the torque of the drive motor 22 constant when the passive wheel 31 goes over the step S, thereby preventing the traveling of the mobile body 100 from becoming unstable. Furthermore, the control unit 70 controls the drive motor 22 again using PI control after the passive wheel 31 goes over the step S, thereby allowing the mobile body 100 to travel stably.

[0121] (Step S9) Next, the control unit 70 performs step S9 (end determination step). In step S9, the control unit 70 determines whether or not the traveling of the moving body 100 is to be ended.

[0122] For example, when it is determined that the moving object 100 has arrived at the destination, the control unit 70 determines to end the traveling of the moving object 100. The control unit 70 may determine whether to end the traveling of the moving object 100 based on an operation input to the grip unit 42 or the like.

[0123] When the control unit 70 determines that the traveling of the moving body 100 is not to be ended, the process returns to step S1, and the moving body 100 continues to travel.

[0124] When the control unit 70 determines that the traveling of the moving body 100 is to end, it stops the drive motor 22 and ends the traveling of the moving body 100.

[0125] The mobile body 100 of this embodiment comprises a drive wheel 21 that contacts the floor surface F, a drive motor 22 that can rotate the drive wheel 21 around a first rotation axis O1 as a center of rotation, a main body 10 that is supported by the drive wheel 21 and moves relative to the floor surface F as the drive wheel 21 rotates around the first rotation axis O1 as a center of rotation, a passive wheel 31 that contacts the floor surface F and is provided forward FR in the direction of travel D of the main body 10 to support the main body 10 and rotates around a second rotation axis O2 as the main body 10 moves relative to the floor surface F, a handle 40 that can be held by a user U, an alarm unit 43 that can notify the user U of predetermined information, a collision detection unit 23 that can detect contact between the passive wheel 31 and a step S on the floor surface F, and a control unit 70 that controls the alarm unit 43 and the drive motor 22 based on the detection results of the collision detection unit 23.

[0126] In this embodiment, the control method for the moving body 100 is such that, when the collision detection unit 23 detects contact between the passive wheel 31 and the step S, the notification unit 43 notifies the user U that the passive wheel 31 has come into contact with the step S, and the torque of the drive motor 22 is maintained constant.

[0127] As a result, it is possible to provide a moving body 100 and a control method for the moving body 100 that can stably guide the user U even in a traveling environment where there are steps S.

[0128] Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0129] (Variation 1) In the above embodiment, the mobile body 100 is equipped with a collision detection unit 23 that detects contact between the passive wheel 31 and a step S, and a step detection unit 60 that detects a step S in the direction of travel of the mobile body 100, but the form of the mobile body is not limited to this.

[0130] The moving body may be configured to be able to detect contact between the driven wheel 31 and the step S and the step S in the moving direction of the moving body 100 using one sensor.

[0131] For example, the step detection unit 60 in the above embodiment may detect contact between the passive wheel 31 and the step S, and transmit the detection result to the control unit 70.

[0132] (Variation 2) In the above embodiment, the control unit 70 controls the drive motor 22 by PI control when the collision detection unit 23 does not detect the step S, but the mode of the control unit is not limited to this.

[0133] The control unit may use a control method other than PI control to control the drive motor 22. Even when the control unit controls the drive motor 22 using a control method other than PI control, the control unit can control the drive motor 22 so that the torque is constant when the passive wheel 31 goes over the step S, thereby realizing stable step overtaking by the moving object.

[0134] (Variation 3) In the above embodiment, the moving body 100 can change its direction of travel by controlling the rotational speed of the drive wheels 21, but the moving body is not limited to this.

[0135] For example, the moving body may include a steering motor that can rotate the passive wheels around the third rotation axis O3. The steering motor is, for example, an electric motor.

[0136] In this case, the control unit controls the steering motor to rotate the passive wheel around the third rotation axis O3, thereby changing the traveling direction of the moving body.

[0137] The moving body may have two steering motors corresponding to the two passive wheels, respectively, or may be configured so that the two passive wheels can be rotated by one steering motor.

[0138] In the step approach step S3 in the above embodiment, the control unit can reduce the approach angle θ of the moving body relative to the step S by controlling the steering motor.

[0139] The Sustainable Development Goals (SDGs) are 17 international goals adopted at the United Nations Summit in September 2015. The mobile object 100 and the method for controlling the mobile object 100 according to this embodiment can contribute to achieving, for example, goal 9, "Build resilient infrastructure, promote inclusive and sustainable industrialization, foster innovation and promote sustainable development." [Explanation of symbols]

[0140] 100 Mobile 10 Main body 21 Drive wheels 22 Drive motor 23 Collision detection unit 31 Passive wheel 40 Handle 43 Information Department 60 Level difference detection unit 70 Control Unit O1 First rotation axis O2 Second rotation axis O3 Third rotation axis D Forward / backward direction (progressing direction) FR front RR rear F Floor S step U user θ Approach angle

Claims

1. A drive wheel that contacts the floor surface; a drive motor capable of rotating the drive wheel around a first rotation shaft; a main body supported by the drive wheel and movable relative to the floor surface as the drive wheel rotates about the first rotation shaft; a passive wheel that is in contact with the floor surface, is provided in front of the main body in the traveling direction, supports the main body, and rotates about a second rotation axis as the main body moves relative to the floor surface; A handle that can be gripped by a user; a notification unit capable of notifying the user of predetermined information; a collision detection unit capable of detecting contact between the passive wheel and a step on the floor surface; a control unit that controls the notification unit and the drive motor based on a detection result of the collision detection unit; Equipped with Mobile object.

2. When the collision detection unit detects contact between the passive wheel and the step, the control unit controlling the notification unit to notify the user that the passive wheel has come into contact with the step; Controlling the drive motor to maintain a constant torque of the drive motor; The moving body according to claim 1 .

3. a passage detection unit capable of detecting that the passive wheel has passed over the step; The control unit controls the drive motor by PI control when the passage detection unit detects that the passive wheel has passed over the step. The moving body according to claim 2 .

4. the collision detection unit and the passage detection unit are encoders capable of measuring the rotation amount of the drive motor; The moving body according to claim 3 .

5. a step detection unit capable of detecting the step in front of the passive wheel, The control unit changes the traveling direction based on a detection result of the step detection unit. The moving body according to any one of claims 1 to 4.

6. the control unit controls the drive motor to reduce the rotation speed of the drive wheel as the passive wheel approaches the step, and changes the traveling direction to reduce the approach angle of the passive wheel with respect to the step. The moving body according to claim 5 .

7. The step detection unit is a distance sensor that is disposed apart from the passive wheel in the traveling direction and is capable of detecting the step. The moving body according to claim 6.

8. A method for controlling a moving body comprising: a drive wheel that contacts a floor surface; a drive motor that can rotate the drive wheel around a first rotation axis; a main body that moves relative to the floor surface as the drive wheel rotates around the first rotation axis; a passive wheel that is provided in front of the main body in a traveling direction and contacts the floor surface, and rotates around a second rotation axis as the main body moves relative to the floor surface; an alarm unit that can notify a user of predetermined information; and a collision detection unit that can detect contact between the passive wheel and a step on the floor surface, When the collision detection unit detects contact between the passive wheel and the step, The notification unit notifies the user that the passive wheel has come into contact with the step, maintaining the torque of the drive motor constant; A method for controlling a moving object.

9. A method for controlling the moving body including a passage detection unit capable of detecting that the passive wheel has passed over the step, When a passage detection unit detects that the passive wheel has passed over the step, the drive motor is controlled by PI control. The method for controlling a moving body according to claim 8.

10. A method for controlling the moving body including a step detection unit capable of detecting the step in front of the passive wheel, As the passive wheel approaches the step, the drive motor is controlled to reduce the rotational speed of the drive wheel, and the traveling direction is changed to reduce the approach angle of the passive wheel with respect to the step. The method for controlling a moving body according to claim 8 or 9.

Images