Robot housing a mobile mechanism

Abstract

We provide robot structures that are mindful of the user. [Solution] The robot (100) comprises a main frame (310), an elastic body (312) that forms a closed space between itself and the main frame (310), a moving mechanism (102) that has a contact surface during movement and is provided to be housed in the closed space, and a drive mechanism that moves the moving mechanism (102) out of or into the closed space. The elastic body (312) elastically deforms under the pressure it receives as the moving mechanism (102) moves forward, enlarging the opening (313) for exposing the moving mechanism (102), and elastically returns to its original shape as the moving mechanism (102) retracts, thereby reducing the opening (313).

Description

Technical Field

[0001] The present invention relates to a robot provided with a moving mechanism.

Background Art

[0002] The development of autonomous mobile robots such as humanoid robots and pet robots that provide interaction and comfort to humans is underway (see, for example, Patent Document 1). As such robots, there are emerging ones that evolve their behavior by autonomously learning based on the surrounding situation and give a sense of life.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When trying to give a robot a sense of familiarity like a pet, skinship with the user is essential. It is necessary not only to realize an appearance and mannerisms that make one want to pick it up instinctively, but also to consider making it easy for the user to pick it up.

[0005] The present invention has been made based on the recognition of the above problems, and its main object is to provide a robot structure that takes into consideration the user.

Means for Solving the Problems

[0006] One aspect of the present invention is a robot. This robot comprises a main frame, an elastic body that forms a closed space between itself and the main frame, a moving mechanism having a contact surface during movement and being housed within the closed space, and a drive mechanism that moves the moving mechanism out of or into the closed space. The elastic body elastically deforms under the pressure it receives as the moving mechanism moves forward, enlarging an opening to expose the moving mechanism, and elastically returns to its original shape as the moving mechanism retracts, thereby reducing the opening.

[0007] Another aspect of the present invention is a robot. This robot comprises a body, a body-forming member that constitutes part of the body and has a housing space inside, a moving mechanism that has a contact surface for movement and is provided to be housed in the housing space, and a drive mechanism that moves the moving mechanism out of the housing space. The body-forming member has a flexible portion that forms an opening that is expanded as the moving mechanism moves forward. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a robot structure that takes user considerations into account. [Brief explanation of the drawing]

[0009] [Figure 1] This is a diagram showing the external appearance of the robot according to the embodiment. [Figure 2] This is a cross-sectional view illustrating the structure of the robot. [Figure 3] This diagram schematically illustrates the structure and operation of the wheel storage mechanism. [Figure 4] This is a hardware configuration diagram of the robot. [Figure 5] This is a functional block diagram of a robot system. [Figure 6] This diagram illustrates the structure and operation of the wheel storage mechanism. [Figure 7] This is a side view showing the wheels extended. [Figure 8] This diagram illustrates the structure and operation of the wheel storage mechanism. [Figure 9] This is a diagram illustrating the general method of assembling the body. [Figure 10] This diagram shows the wheel storage structure according to the first modified example. [Figure 11] This diagram shows the wheel storage structure according to the second modified example. [Figure 12] This is a side view showing the wheel storage structure according to the third and fourth modified examples. [Figure 13] This diagram shows the wheel storage mechanism according to the fifth modified example. [Figure 14] This diagram shows the wheel storage mechanism according to the fifth modified example. [Figure 15] This diagram shows the wheel storage mechanism according to the sixth modified example. [Figure 16] This diagram shows the wheel storage mechanism according to the seventh modified example. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below with reference to the drawings. For convenience, the positional relationships of each structure may be expressed based on the illustrated state in the following description. In addition, substantially identical components in the following embodiments and their modifications will be denoted by the same reference numerals, and their descriptions may be omitted as appropriate.

[0011] The robot of this embodiment has wheels as a mobility mechanism and a structure that allows the wheels to be housed within the body. Specifically, a cover is provided on the side of the main frame, and the enclosed space between the two serves as the wheel housing space. Because the cover is flexible and elastic, it is pushed open when the wheels are extended from the wheel housing space. When the wheels are retracted into the wheel housing space, the cover returns to its original shape. This flexible movement (deformation) of the cover is reminiscent of a living organism's body part, giving the user a sense of familiarity similar to that with a pet. Because the wheels are fully housed, it becomes easy to pick up the robot, and it is also possible to prevent the user from touching the contact surface of the wheels. According to this embodiment, a robot that is considerate of the user is provided. The following describes the specific configuration of such a robot.

[0012] FIG. 1 is a diagram showing the appearance of the robot 100 according to the embodiment. FIG. 1(a) is a front view, and FIG. 1(b) is a side view. The robot 100 is an autonomous mobile robot that determines actions and gestures based on the external environment and internal state. The external environment is recognized by various sensors such as cameras and thermosensors. The internal state is quantified as various parameters representing the emotions of the robot 100. The robot 100 has the interior of the owner's house as its operating range. Hereinafter, a person related to the robot 100 is referred to as a "user".

[0013] The body 104 of the robot 100 has an overall rounded shape and includes an outer skin 314 formed of a soft and elastic material such as urethane, rubber, resin, or fiber. The robot 100 may be dressed in clothes. The total weight of the robot 100 is about 5 to 15 kilograms, and the height is about 0.5 to 1.2 meters. Due to appropriate weight, roundness, softness, and good texture, the user can easily hold the robot 100 and is motivated to do so.

[0014] The robot 100 includes a pair of front wheels 102 (left front wheel 102a and right front wheel 102b) and one rear wheel 103. The front wheels 102 are drive wheels, and the rear wheel 103 is a driven wheel. The front wheels 102 do not have a steering mechanism, but the rotational speed and direction of the left and right wheels can be individually controlled. The rear wheel 103 is a caster and is rotatable to move the robot 100 forward, backward, left, and right. The rear wheel 103 may be an omnidirectional wheel. By increasing the rotational speed of the right front wheel 102b more than that of the left front wheel 102a, the robot 100 can turn left or rotate counterclockwise. By increasing the rotational speed of the left front wheel 102a more than that of the right front wheel 102b, the robot 100 can turn right or rotate clockwise.

[0015] The front wheels 102 and rear wheels 103 can be fully retracted into the body 104 by a drive mechanism (rotation mechanism, linkage mechanism) described later. The lower half of the body 104 is provided with a pair of left and right covers 312, which form a flexible body and can also house the front wheels 102. The covers 312 have slits 313 (openings) that open forward, and the front wheels 102 can be advanced through these slits 313 and exposed to the outside. The covers 312 function as "body forming members," and the area around the slits 313 functions as a "flexible part."

[0016] Even when the robot is moving, most of the wheels are hidden within the body 104. However, when the wheels are fully retracted into the body 104, the robot 100 becomes immobile. That is, as the wheels are retracted, the body 104 lowers and sits on the floor surface F. In this seated state, the flat seating surface 108 (ground contact surface) formed on the bottom of the body 104 comes into contact with the floor surface F. Details of the structure and operation of the wheel retraction mechanism will be described later.

[0017] The robot 100 has two hands 106. The hands 106 do not have the function of grasping objects. The hands 106 can perform simple movements such as lifting, shaking, and vibrating by pulling or releasing internal wires (not shown). The two hands 106 can also be controlled individually.

[0018] The front of the robot 100's head (face) is equipped with two eyes 110. The eyes 110 display various expressions using liquid crystal or organic EL elements. The robot 100 also has a built-in speaker and can emit simple sounds. Horns 112 are attached to the top of the robot 100's head. The horns 112 have built-in panoramic cameras that can capture images in all directions simultaneously, up, down, left, and right. In addition, a high-resolution camera (not shown) is provided on the front of the robot 100's head.

[0019] In addition, the robot 100 incorporates various sensors, including a temperature sensor for detecting ambient temperature, a microphone array with multiple microphones, a shape measuring sensor (depth sensor) capable of measuring the shape of the object being measured, and an ultrasonic sensor.

[0020] Figure 2 is a schematic cross-sectional view showing the structure of robot 100. The body 104 includes a base frame 308, a main frame 310, an outer shell 314, and a pair of covers 312. The base frame 308 forms the axis of the body 104 and supports the internal mechanism. The base frame 308 is constructed by erecting a plurality of side plates 336 on a lower plate 334. Inside the base frame 308 are a battery 118, a control circuit 342, and various actuators. The bottom surface of the lower plate 334 forms the seating surface 108.

[0021] The main frame 310 includes a head frame 316 and a torso frame 318. The head frame 316 is hollow and hemispherical, forming the head skeleton of the robot 100. The torso frame 318 is rectangular and cylindrical, forming the torso skeleton of the robot 100. The lower end of the torso frame 318 is fixed to a lower plate 334. The head frame 316 is connected to the torso frame 318 via a connecting mechanism 330.

[0022] The head frame 316 has a yaw axis 321, a pitch axis 322, and a roll axis 323. Rotation of the head frame 316 around the yaw axis 321 (yawing) enables head-turning motion, rotation around the pitch axis 322 (pitching) enables nodding, looking up, and looking down motion, and rotation around the roll axis 323 (rolling) enables tilting the head from side to side. The position and angle of each axis can change in three-dimensional space depending on the driving mode of the connection mechanism 330. The connection mechanism 330 consists of a link mechanism and is driven by multiple motors installed on the body frame 318.

[0023] The torso frame 318 houses the base frame 308 and the wheel drive mechanism 370. The wheel drive mechanism 370 includes a front-wheel drive mechanism and a rear-wheel drive mechanism that extend and retract the front wheels 102 and rear wheels 103 from the body 104, respectively. The front wheels 102 and rear wheels 103 function as a "movement mechanism" to move the robot 100. The front wheels 102 have a direct-drive motor (hereinafter referred to as "DD motor") in their center. Therefore, the left front wheel 102a and the right front wheel 102b can be driven individually. The front wheels 102 are rotatably supported by a wheel cover 105, and the wheel cover 105 is rotatably supported by the torso frame 318.

[0024] A pair of covers 312 are provided to cover the fuselage frame 318 from the left and right sides, and have a smooth curved shape to give the outline of the body 104 a rounded shape. A closed space is formed between the fuselage frame 318 and the covers 312, and this closed space serves as the housing space S for the front wheels 102. The rear wheels 103 are housed in a housing space provided at the lower rear of the fuselage frame 318.

[0025] The outer shell 314 covers the main frame 310 from the outside. The outer shell 314 has a thickness that a person can feel as elastic and is made of an elastic material such as urethane sponge. As a result, when a user hugs the robot 100, they feel a moderate softness and can engage in natural physical contact, similar to how a person would interact with a pet. The outer shell 314 is attached to the main frame 310 in such a manner that the cover 312 is exposed.

[0026] A touch sensor is positioned between the main frame 310 and the outer shell 314. A touch sensor is embedded in the cover 312. All of these touch sensors are capacitive sensors and detect touches across almost the entire surface of the robot 100. In a modified example, The touch sensor may be embedded in the outer casing 314, or it may be placed inside the main frame 310.

[0027] The hand 106 is integrally formed with the outer skin 314. An opening 390 is provided at the upper end of the outer skin 314. The lower end of the horn 112 is connected to the head frame 316 via the opening 390.

[0028] The drive mechanism for driving the hand 106 includes a wire 134 embedded in the outer sheath 314 and a drive circuit 340 (electrical circuit) for it. In this embodiment, the wire 134 is made of a shape memory alloy wire, which shrinks and hardens when heated and relaxes and stretches when cooled. Lead wires drawn from both ends of the wire 134 are connected to the drive circuit 340. When the switch of the drive circuit 340 is turned on, current is supplied to the wire 134 (shape memory alloy wire).

[0029] The wire 134 is molded or braided to extend from the outer sheath 314 to the hand 106. Lead wires are drawn out from both ends of the wire 134 into the body frame 318. One wire 134 may be provided on each side of the outer sheath 314, or multiple wires may be provided in parallel. By energizing the wire 134, the arm (hand 106) can be raised, and by cutting off the power, the arm (hand 106) can be lowered.

[0030] Figure 3 schematically illustrates the structure and operation of the wheel storage mechanism. Figure 3(a) is a side view, and Figure 3(b) is a front view. In the figure, the dotted lines indicate the state in which the wheels have emerged from the storage space S and are ready to move, and the solid lines indicate the state in which the wheels are stored in the storage space S.

[0031] The wheel drive mechanism 370 includes a front wheel drive mechanism 374 and a rear wheel drive mechanism 376. The front wheel drive mechanism 374 includes a pivot shaft 378 and an actuator 379. The pivot shaft 378 is connected to the wheel cover 105. In this embodiment, a motor is used as the actuator 379. By rotating the wheel cover 105 through the drive of the actuator 379, the front wheel 102 can be driven to move forward and backward from the housing space S to the outside. In this way, the front wheel drive mechanism 374 functions as a "rotation mechanism".

[0032] The rear-wheel drive mechanism 376 includes a pivot shaft 404 and an actuator 406. A rotating shaft 407 is supported at the center of the pivot shaft 404. A bifurcated arm 408 extends from the rotating shaft 407, and an axle 410 is integrally attached to its end. The rear wheels 103 are rotatably supported on the axle 410. The rotating shaft 407 is freely rotatable around its own axis, allowing the orientation (direction of travel) of the rear wheels 103 to be changed arbitrarily. The actuator 406 drives the rear wheels 103 forward and backward from the rear storage space to the outside. In this way, the rear-wheel drive mechanism 376 functions as a "linkage mechanism".

[0033] When the wheels are retracted, actuators 379 and 406 are driven in one direction. At this time, the wheel cover 105 rotates around the pivot axis 378, and the front wheel 102 rises from the floor surface F. Also, the arm 408 rotates around the pivot axis 404, and the rear wheel 103 rises from the floor surface F (see dashed arrow). As a result, the body 104 lowers, and the seating surface 108 touches the floor surface F (see solid arrow). This makes the robot 100 sit down. By driving actuators 379 and 406 in the opposite direction, each wheel can be extended, and the robot 100 can be made to stand up.

[0034] Furthermore, a rear cover 107, resembling a tail, is provided on the outside of the rear wheel 103, and opens and closes the lower rear opening of the body 104 in conjunction with the rear wheel 103. That is, when the rear wheel 103 is extended, the rear cover 107 opens, and when the rear wheel 103 is retracted, the rear cover 107 closes.

[0035] Figure 4 is a hardware configuration diagram of robot 100. Robot 100 includes an internal sensor 128, a communication device 126, a storage device 124, a processor 122, a drive mechanism 120, and a battery 118. The drive mechanism 120 includes the aforementioned connection mechanism 330 and wheel drive mechanism 370. The processor 122 and storage device 124 are included in the control circuit 342. Each unit is connected to the others by power lines 130 and signal lines 132. The battery 118 supplies power to each unit via the power lines 130. Each unit sends and receives control signals via the signal lines 132. The battery 118 is a lithium-ion secondary battery and is the power source for robot 100.

[0036] The internal sensor 128 is a collection of various sensors built into the robot 100. Specifically, it includes cameras (360-degree camera, high-resolution camera), a microphone array, a distance sensor (infrared sensor), a thermosensor, a touch sensor, an accelerometer, and an odor sensor. The touch sensor covers most of the body 104 and detects user touch based on changes in capacitance. The odor sensor is a known sensor that applies the principle that electrical resistance changes due to the adsorption of odor-causing molecules.

[0037] The communication device 126 is a communication module that performs wireless communication with various external devices, such as the server 200 (described later), the external sensor 114, and the user's portable device. The storage device 124 consists of non-volatile memory and volatile memory and stores computer programs and various setting information. The processor 122 is a means for executing computer programs. The drive mechanism 120 is an actuator that controls the internal mechanism. Other components such as a display and speaker are also installed.

[0038] The processor 122 selects actions for the robot 100 while communicating with the server 200 and external sensors 114 via the communication device 126. Various external information obtained by the internal sensors 128 also influences action selection. The drive mechanism 120 primarily controls the movement of the wheels (front wheels 102) and the head (head frame 316). The drive mechanism 120 changes the direction and speed of movement of the robot 100 by changing the rotation speed and direction of rotation of each of the two front wheels 102. The drive mechanism 120 can also raise and lower the wheels (front wheels 102 and rear wheels 103). When the wheels are raised, they are completely retracted into the body 104, and the robot 100 comes into contact with the floor surface F at the seating surface 108, entering a seated state. The drive mechanism 120 also controls the hands 106 via wires 134.

[0039] Figure 5 is a functional block diagram of the robot system 300. The robot system 300 includes a robot 100, a server 200, and a number of external sensors 114. Each component of the robot 100 and the server 200 is realized by hardware including a CPU (Central Processing Unit) and various coprocessors, memory and storage devices, and wired or wireless communication lines connecting them, as well as software stored in the storage devices that supplies processing instructions to the arithmetic units. The computer program may consist of device drivers, an operating system, various application programs located at a higher layer, and libraries that provide common functions to these programs. The blocks described below represent functional units, not hardware units. Some of the functions of the robot 100 may be realized by the server 200, and some or all of the functions of the server 200 may be realized by the robot 100.

[0040] Multiple external sensors 114 are pre-installed inside the house. The position coordinates of the external sensors 114 are registered in the server 200. Based on the information obtained from the robot 100's internal sensors 128 and the multiple external sensors 114, the server 200 determines the basic operation of the robot 100. The movement is determined. The external sensor 114 is for augmenting the sensory organs of the robot 100, and the server 200 is for augmenting the processing capabilities of the robot 100. The robot 100's communicator 126 communicates periodically with the external sensor 114, and the server 200 determines the robot 100's position using the external sensor 114.

[0041] (Server 200) The server 200 includes a communication unit 204, a data processing unit 202, and a data storage unit 206. The communication unit 204 is responsible for communication processing with the external sensor 114 and the robot 100. The data storage unit 206 stores various types of data. The data processing unit 202 performs various processes based on the data acquired by the communication unit 204 and the data stored in the data storage unit 206. The data processing unit 202 also functions as an interface for the communication unit 204 and the data storage unit 206.

[0042] The data storage unit 206 includes a motion storage unit 232, a map storage unit 216, and a personal data storage unit 218. The robot 100 has multiple motion patterns. Various motions are defined, such as shaking its hand 106, approaching the user in a meandering motion, and staring at the user with its head tilted.

[0043] The motion storage unit 232 stores "motion files" that define the control content of the motions. Each motion is identified by a motion ID. The motion files are also downloaded to the motion storage unit 160 of the robot 100. Which motion to execute may be decided by the server 200 or by the robot 100. Most of the robot 100's motions are composed of compound motions that include multiple unit motions.

[0044] The map storage unit 216 stores not only behavior maps that define the robot's actions according to the situation, but also maps showing the arrangement of obstacles such as chairs and tables. The personal data storage unit 218 stores user information. Specifically, it stores master information indicating the level of familiarity with the user and the user's physical and behavioral characteristics. Other attribute information such as age and gender may also be stored.

[0045] Robot 100 has an internal parameter called "affection level" for each user. When Robot 100 recognizes actions that show it is fond of the user, such as picking it up or talking to it, its affection level with that user increases. The affection level will be lower for users who do not interact with Robot 100, users who act rudely, or users it does not encounter often.

[0046] The data processing unit 202 includes a position management unit 208, a recognition unit 212, a motion control unit 222, and a closeness management unit 220. The position management unit 208 identifies the position coordinates of the robot 100. The position management unit 208 may also track the user's position coordinates in real time.

[0047] The recognition unit 212 recognizes the external environment. Recognition of the external environment includes various types of recognition, such as recognition of weather and season based on temperature and humidity, and recognition of shaded areas (safe zones) based on light intensity and temperature. The recognition unit 150 of the robot 100 acquires various environmental information using the internal sensor 128, processes it, and then transfers it to the recognition unit 212 of the server 200.

[0048] The recognition unit 212 further includes a person recognition unit 214 and a response recognition unit 228. The person recognition unit 214 determines which person the captured user belongs to by comparing the feature vector extracted from the image captured by the robot 100's built-in camera with the feature vector of a user (cluster) pre-registered in the personal data storage unit 218 (user identification processing). The person recognition unit 214 includes an expression recognition unit 230. The expression recognition unit 230 determines which person the captured user belongs to. By using image recognition to capture emotions, we can estimate the user's feelings.

[0049] The response recognition unit 228 recognizes various responses made to the robot 100 and classifies them as pleasant or unpleasant. The response recognition unit 228 also recognizes the user's responses to the robot 100's actions and classifies them as positive or negative responses. The distinction between pleasant and unpleasant responses is determined by whether the user's response is biologically pleasing or unpleasant.

[0050] The motion control unit 222 works in cooperation with the motion control unit 152 of the robot 100 to determine the motion of the robot 100. The motion control unit 222 creates a target location for the robot 100's movement and a movement route for that location. The motion control unit 222 may create multiple movement routes and then select one of them. The motion control unit 222 selects the motion of the robot 100 from multiple motions stored in the motion storage unit 232.

[0051] The intimacy management unit 220 manages the intimacy level for each user. Intimacy levels are registered as part of the personal data in the personal data storage unit 218. When a pleasant action is detected, the intimacy management unit 220 increases the intimacy level for that user. When an unpleasant action is detected, the intimacy level decreases. In addition, the intimacy level of users who have not been viewed for a long period of time gradually decreases.

[0052] (Robot 100) Robot 100 includes a communication unit 142, a data processing unit 136, a data storage unit 148, an internal sensor 128, and a drive mechanism 120. The communication unit 142 corresponds to the communication device 126 (see Figure 4) and is responsible for communication processing with the external sensor 114, the server 200, and other robots 100. The data storage unit 148 stores various types of data. The data storage unit 148 corresponds to the storage device 124 (see Figure 4). The data processing unit 136 performs various processes based on the data acquired by the communication unit 142 and the data stored in the data storage unit 148. The data processing unit 136 corresponds to the processor 122 and the computer program executed by the processor 122. The data processing unit 136 also functions as an interface to the communication unit 142, the internal sensor 128, the drive mechanism 120, and the data storage unit 148.

[0053] The data storage unit 148 includes a motion storage unit 160 that defines various motions of the robot 100. Various motion files are downloaded to the motion storage unit 160 from the motion storage unit 232 of the server 200. Motions are identified by motion IDs. To represent various motions, the operation timing, operation duration, and direction of various actuators (drive mechanisms 120) are defined chronologically in the motion files.

[0054] Various data may be downloaded to the data storage unit 148 from the map storage unit 216 and the personal data storage unit 218.

[0055] The data processing unit 136 includes a recognition unit 150 and an operation control unit 152. The recognition unit 150 interprets external information obtained from the internal sensor 128. The recognition unit 150 is capable of visual recognition (visual unit), smell recognition (olfactory unit), sound recognition (auditory unit), and tactile recognition (tactile unit).

[0056] The recognition unit 150 periodically captures images of the outside world using its built-in panoramic camera and detects moving objects such as people and pets. The recognition unit 150 extracts feature vectors from the captured images of moving objects. As described above, the feature vector is a set of parameters (feature quantities) that represent the physical and behavioral characteristics of the moving object. When a moving object is detected, physical and behavioral characteristics are also extracted from odor sensors, built-in sound-collecting microphones, temperature sensors, etc. These features are also quantified and become components of the feature vector.

[0057] In response to the interaction recognized by the recognition unit 150, the intimacy management unit 220 of the server 200 changes the intimacy level with the user. In principle, the intimacy level increases for users who perform pleasant actions and decreases for users who perform unpleasant actions.

[0058] The motion control unit 152, together with the motion control unit 222 of the server 200, determines the direction of movement for the robot 100. The server 200 may determine movement based on an action map, while the robot 100 may decide on immediate movements such as avoiding obstacles. The drive mechanism 120 drives the front wheels 102 (wheel drive mechanism 370) according to the instructions of the motion control unit 152, thereby directing the robot 100 toward the target location.

[0059] The motion control unit 152 works in cooperation with the motion control unit 222 of the server 200 to determine the motion of the robot 100. Some motions may be determined by the server 200, while others may be determined by the robot 100. Alternatively, the robot 100 may determine the motion, but if the processing load on the robot 100 is high, the server 200 may determine the motion. The server 200 may determine the base motion, and the robot 100 may determine additional motions. How the motion determination process is divided between the server 200 and the robot 100 should be designed according to the specifications of the robot system 300.

[0060] The motion control unit 152 instructs the drive mechanism 120 to execute the selected motion. The drive mechanism 120 controls each actuator according to the motion file. If the motion file defines head movement or wheel movement, the motion control unit 152 drives the drive mechanism 120 to execute that motion control.

[0061] The motion control unit 152 can perform a motion of raising both hands 106 as a gesture of asking to be held when a user with whom the robot has a close relationship is nearby, or it can express a motion of not wanting to be held by repeatedly rotating in the opposite direction and stopping while keeping the left and right front wheels 102 retracted. The drive mechanism 120 drives the front wheels 102, hands 106, and neck (head frame 316) according to the instructions of the motion control unit 152, thereby causing the robot 100 to express various motions.

[0062] Next, we will describe the characteristic configuration and operation of robot 100. Figures 6 to 8 illustrate the structure and operation of the wheel retraction mechanism. Figure 6 is a perspective view showing the lower half of the robot 100 with the outer shell 314 removed. Figure 6(a) shows the wheel retracted state, and Figure 6(b) shows the wheel extended state. Figure 7 is a side view showing the wheel extended state. Figure 8 is a partially enlarged view of the wheel extension operation seen from the front. Figures 8(a) to (f) show the wheel extension process.

[0063] As shown in Figure 6(a), a pair of covers 312 are configured symmetrically with respect to the main frame 310 and are joined at their front and rear surfaces (joint 502). These covers 312 together with the main frame 310 form the body 104. In this embodiment, the two covers are joined by welding or adhesive, but fastening by screws or other fixing methods may be used. The covers 312 are made of a flexible and elastic resin material (in this embodiment, rubber, silicone rubber, etc.). A vertical slit 313 is provided on the cover 312 from the side to the front. The slit 313 forms an arc shape (fan shape) when viewed from the side of the body 104.

[0064] The cover 312 has a mounting portion 510 on the inside and a bulging portion 512 on the outside, with the slit 313 as the boundary. The mounting portion 510 is fixed to the main frame 310. The bulging portion 512 is The bulge 512 has a shape that bulges away from the main frame 310, forming a closed space between it and the main frame 310. A spring material 514 is embedded (insert molded) in the bulge 512 along its shape. The spring material 514 is obtained by punching out a frame shape from a metal plate (spring steel plate) using sheet metal processing, and then shaping it into a curved shape. The cover 312 is obtained by setting the spring material 514 in a predetermined mold and performing injection molding of resin material. The chamber of this mold also has a curved shape that conforms to the shape of the cover 312. The spring material 514 functions as the core material of the cover 312 and, together with the resin material (rubber), constitutes an "elastic body".

[0065] Furthermore, the spring material 514 has multiple small holes 516 formed at predetermined intervals along its entire length. This allows the resin material to wrap around the front and back of the spring material 514 through these small holes 516 during injection molding, thereby stabilizing the joint between the spring material 514 and the resin material. Circular holes 518 are provided at both ends (upper and lower ends) of the slit 313 (see Figure 7) to alleviate stress concentration at the ends when the slit 313 is expanded, preventing the cover 312 from breaking.

[0066] When the wheels are retracted, the slit 313 is closed as shown in the figure. The front wheel 102 is completely housed inside the cover 312. The storage space S inside the cover 312 is just large enough to accommodate one wheel cover 105 which is integrated with the front wheel 102.

[0067] As shown in Figure 6(b), when the wheels are driven, the front wheel 102 protrudes from the slit 313 and is exposed to the outside of the cover 312. During this process of the front wheel 102's extension, the wheel cover 105 pushes the bulge 512 outward. Due to its elasticity and flexibility, the cover 312 bends around the part where the wheel cover 105 comes into contact, as shown in the figure, and the part where the wheel cover 105 has passed elastically returns to its original shape. In other words, the deformation region of the slit 313 changes during the process of the front wheel 102's extension. When the wheels are retracted, the reverse wheel operation occurs.

[0068] As shown in the diagram, the front wheel 102 is mostly covered by the wheel cover 105, except for its contact surface. The gap between the wheel cover 105 and the front wheel 102 is made very small to prevent surrounding objects from getting caught or pinched. By making the wheel cover 105, rather than the front wheel 102 itself, contact with the slit 313 in the cover 312, the cover 312 is prevented from getting dirty when inserting or removing the front wheel 102.

[0069] The outer surface of the wheel cover 105 is provided with a tapered surface 520 that slopes toward the outer surface of the front wheel 102 as it moves radially outward from the front wheel 102. When the wheel extends, the outer surface of the wheel cover 105 comes into contact with the slit 313. At this time, the slit 313 can be smoothly pushed open along the tapered surface 520, allowing the front wheel 102 to be moved in and out smoothly.

[0070] Furthermore, by providing the tapered surface 520, the wheel cover 105 has an outer surface with a complementary shape to the inner surface of the bulge 512. As a result, even if external pressure acts on the bulge 512 in the wheel storage state shown in Figure 6(a), the wheel cover 105 supports it from the inside, preventing or suppressing deformation of the bulge 512. For example, when a user hugs the robot 100, the force of that hug may cause the bulge 512 to elastically deform. Even in such a case, the rigid wheel cover 105 functions as a core material, preventing excessive deformation or crushing of the bulge 512.

[0071] As shown in Figure 7, the wheel cover 105 rotates around a pivot shaft 522 located near the bottom of the main frame 310. The slit 313 is located on the track of the front wheel 102 in the cover 312 (see dashed line). On the inside of the cover 312 (more specifically, the inner surface near the slit 313 in the mounting portion 510 and the bulging portion 512) there is a sliding member 53 A sliding member 535 is provided. The sliding member 535 is a sheet-like member made of a highly wear-resistant resin (for example, polyacetal (POM)), and is disposed at the contact portion with the wheel cover 105 near the slit 313. The sliding member 535 contacts the wheel cover 105 and smoothly guides it when the front wheel 102 is driven to move forward and backward, thereby preventing or suppressing wear (deterioration) of the cover 312.

[0072] The spring material 514 has an annular base portion 540 along the vicinity of the periphery of the bulge portion 512 and a plurality of frame-forming portions 542 that span the base portion 540 radially, thereby forming a framework structure. By filling the resin material with appropriate spacing between the base portion 540 and the frame-forming portions 542, and between adjacent frame-forming portions 542 (in other words, by setting the spring material 514 to an appropriate shape, thickness, and width), appropriate elasticity is obtained for the bulge portion 512 as a whole. The base portion 540 extends along the vicinity of the slit 313.

[0073] The spring material 514 also functions as an electrode for a capacitive sensor (proximity sensor). When a user touches the cover 312, such as when picking up the robot 100, the capacitance around that electrode changes. By detecting this change, the user's touch can be determined. In this way, by arranging the spring material 514 across the entire cover 312, which is the body of the robot 100, and securing a large area as a sensor electrode, the sensitivity of the touch sensor can be increased.

[0074] When the wheels are driven, the front wheels 102 are gradually pushed out from the cover 312 as shown in Figure 8(a)→(b)→(c)→(d)→(e)→(f), and eventually most of them are exposed to the outside. When the wheels are retracted, conversely, the front wheels 102 are gradually pulled back into the cover 312 as shown in Figure 8(f)→(e)→(d)→(c)→(b)→(a), and eventually completely retracted. At this time, the slit 313 also closes. The bulging portion 512 has a three-dimensional curved surface shape like a bowl, but as shown in the figure, its curved surface shape changes during the process of extending and retracting the wheels. This behavior during wheel movement results in the front wheels 102 being flexibly extended and retracted from the cover 312, giving the user a feeling of biological softness and warmth.

[0075] Figure 9 is a schematic diagram illustrating the assembly method of body 104. Figures 9(a) to (c) show the assembly process. In the assembly process of the body 104, the main frame 310 and its internal mechanisms are assembled as shown in Figure 9(a). The front wheels 102 and wheel covers 105 are positioned in the retracted (stored) state.

[0076] Next, as shown in Figure 9(b), the pair of covers 312 are assembled and fixed to the main frame 310 from the left and right sides. Although not explained above, several reinforcing ribs 526 are provided on the inner surface of the cover 312 in positions that do not interfere with the front wheel 102, allowing the cover 312 to be assembled stably and smoothly.

[0077] Next, as shown in Figure 9(c), the outer skin 314 is placed over the head from the side. The upper front of the outer skin 314 is provided with a circular opening 528 to expose the face area of ​​the head frame 316. The outer skin 314 extends to the front and back sides of the robot 100, and these extended portions 530 are configured so as not to interfere with the slit 313.

[0078] The robot 100 has been described above based on the embodiment. According to this embodiment, the cover 312 elastically deforms due to the pressing force it receives as the front wheels 102 extend, enlarging the slit 313, and elastically returns to its original state as the front wheels 102 retract, reducing the slit 313. The deformation pattern of the slit 313 is reminiscent of the movement of soft parts of living organisms. This makes the robot 100 seem more lifelike and approachable, like a pet. By fully retracting the wheels, they do not interfere with the user when they pick up the robot 100, and their clothes do not get dirty. This also prevents such issues and demonstrates thoughtful consideration for the user.

[0079] It should be noted that the present invention is not limited to the embodiments and modifications described above, and the components can be modified and implemented without departing from the spirit of the invention. Various inventions may be formed by appropriately combining the multiple components disclosed in the embodiments and modifications described above. In addition, some components may be deleted from all the components shown in the embodiments and modifications described above.

[0080] Figure 10 is a diagram showing a wheel housing structure according to the first modified example. Figure 10(a) is a side view showing the structure of the wheel housing and its surroundings. Figure 10(b) is a cross-sectional view taken along the arrow AA in Figure 10(a). Figure 10(c) is a view taken along the arrow B in Figure 10(a) (front view).

[0081] As shown in Figure 10(a), in this modified example, a shielding portion 550 is provided near the upper end of the slit 313 at a position that does not interfere with the track of the front wheel 102 and the wheel cover 105. The shielding portion 550 is made of a flexible resin material and has a pleated structure as shown in Figure 10(b). The open end of the pleated structure is integrated with the opening of the slit 313, and the folded portion is positioned inside the slit 313. When the slit 313 is pushed open when the wheel is extended, and when it is retracted when the wheel is stored, the pleated structure changes between the standard state on the left and the expanded state on the right in Figure 10(b).

[0082] With this configuration, as shown in Figure 10(c), the internal structure (mechanical structure) of the robot 100 can be hidden from view from the front. In other words, it prevents the user from being disappointed by the mechanical structure being visible when the wheels extend. Also, if a user tries to forcibly open the slit 313, such as a child playing with it, the pleated structure acts as a stopper in the expanded state, preventing damage to the cover 312.

[0083] Figure 11 is a diagram showing a wheel storage structure according to a second modified example. Figure 11(a) shows the wheel storage state with the outer casing 314 removed. Figure 11(b) shows the wheel extended state with the outer casing 314 removed. Figure 11(c) shows the wheel extended state with the outer casing 314 attached.

[0084] As shown in Figures 11(a) and (b), in this modified example, the cover 612 is the same as the cover 312 except that it does not have the slit 313 as in the above embodiment. When the wheels are retracted, the inner edge of the cover 612 abuts against the side surface of the body frame 318, forming a storage space S inside it. When the front wheels 102 advance during wheel drive, the wheel cover 105 pushes aside the gap between the body frame 318 and the cover 612. At this time, the lower part of the cover 612 is pushed outward, and an opening 613 is formed between the side surface of the body frame 318 and the cover 612. As shown in Figure 11(c), the outer skin 314 does not interfere with the opening 613. The cover 612 functions as a "body forming member," and its lower inner edge functions as a "flexible portion."

[0085] Even with this configuration, the cover 612 elastically deforms (bends) due to the pressing force from the wheel cover 105 as the front wheel 102 advances, thereby enlarging the opening 613. When the opening 613 is pushed open, the cover 612 generates a biasing force in the direction of closing it, and elastically returns to its original position as the front wheel 102 retracts, closing the opening 613. As a result, the same effects as in the above embodiment can be obtained.

[0086] Figure 12 is a side view showing the wheel storage structure according to the third and fourth modified examples. In the third and fourth modifications, the shape of the spring material differs from that of the spring material 514 in the above embodiment. In the third modification shown in Figure 12(a), the portion 644 of the base portion 640 of the spring material 614 that follows the track of the front wheel 102 is configured to be relatively separated from the slit 313. As a result, the portion of the bulging portion 512 that is pushed out by the wheel cover 105 is made more flexible. With this configuration, the area where the slit 313 expands when the wheel extends can be made more limited, and the internal structure can be made less visible from the outside.

[0087] In the fourth modified example shown in Figure 12(b), the portion of the base 740 of the spring material 714 that follows the track of the front wheel 102 is partially omitted. As a result, similar to the third modified example, the portion of the bulge 512 that is pushed out by the wheel cover 105 is made more flexible. Furthermore, an arc-shaped tactile-forming portion 750 is provided on the outer surface of the bulge 512 near the periphery that follows the track of the front wheel 102. The tactile-forming portion 750 forms a softer region than other areas of the bulge 512, providing the user with a pleasant tactile sensation.

[0088] Figures 13 and 14 illustrate the wheel storage mechanism according to the fifth modified example. Figure 13 shows a cross-sectional view of the robot, and Figure 14 shows an example of the robot's operation using this mechanism. As shown in Figure 13, in the fifth modified example, the forward and backward drive of the left and right front wheels 102 is controlled individually. That is, the pivot shaft 378a of the left front wheel 102a is connected to actuator 379a, and the pivot shaft 378b of the right front wheel 102b is connected to actuator 379b. Actuators 379a and 379b each consist of independent motors and are driven individually.

[0089] This configuration allows for staggered timing of forward and backward movement between the left and right wheels. As shown in Figures 14(a) to (c), the robot 100 can perform a variety of motions, such as tilting its body from side to side while standing up one leg at a time, swaying up and down from side to side from a standing position, or moving while swaying. Biological movements can also be realized.

[0090] In the above embodiment, the front wheels 102 were exemplified as the moving mechanism housed in the housing space S, but the rear wheels 103 may be housed in the same way. That is, a closed space (housing space) may be provided between the back of the main frame 310 and the cover (elastic body), and the rear wheels 103 may be housed there. The cover elastically deforms under the pressure it receives as the rear wheels 103 advance, enlarging the opening (slit) for exposing the rear wheels 103, and elastically returns to its original state as the rear wheels 103 retract, reducing the opening. Although not mentioned in the above embodiment, the rear wheels 103 may be made of ball-shaped casters. Alternatively, other wheels that can move freely in all directions, such as omni-wheels, may be used as the rear wheels 103.

[0091] In the above embodiment, the cover 312 is obtained by insert molding the spring material 514 into the resin material, but it may also be configured to be attached to the surface of the resin material. For example, the spring material 514 may be fixed by attaching it to the inner surface of the bulging portion 512. Alternatively, a configuration may be adopted in which two pieces of rubber are bonded together with the spring material 514 sandwiched in between.

[0092] The above embodiment shows an example in which a pair of covers 312 are joined together. In a modified example, instead of joining the left and right covers, they may be assembled to the left and right sides of the main frame 310, respectively. Alternatively, spring material may be placed in the left and right regions of a single resin material and wrapped around the robot's torso frame. The covers may also be integrated as part of the outer skin and placed over the robot.

[0093] In the above embodiment, the cover is made of rubber, but it may also be made of a flexible material such as a low-elasticity resin. The same material as the outer shell may be used for the cover. Although not mentioned in the above embodiment, a magnet may be provided at or near the edge of the slit 313. Specifically, a magnet may be placed at the edge of the slit 313 on the mounting portion 510 side. This causes the metal spring material 514 on the bulging portion 512 side and the magnet on the mounting portion 510 side to attract each other by magnetic force, making it easier to close the slit 313 and thus minimizing the visibility of the internal structure of the robot 100. This makes it easier to close the slit 313. The edge on the bulging portion 512 side and the edge on the mounting portion 510 side become more closely fitted together. Alternatively, a magnet may also be placed on the edge on the bulging portion 512 side of the slit 313. This causes the magnet on the bulging portion 512 side and the magnet on the mounting portion 510 side to attract each other by magnetic force, making it easier to close the slit 313.

[0094] In the above embodiment, an example of the framework structure of the spring material 514 is shown, but a lattice shape, mesh shape, honeycomb shape, or other shapes may be used. A spring material without a framework structure may also be used, but the shape of the spring material can be adjusted by providing notches or the like to obtain appropriate elasticity. In this embodiment, a metal plate that functions as a capacitance sensor was used as the spring material 514, but a material without sensor function may also be used. The spring material may be a resin material with greater elasticity than the mold resin (resin for insert molding). For example, the elasticity may be improved by thermoforming a plate made of resin. Specifically, a mold is prepared that conforms to the shape of the bulge 512. Then, the resin plate is heated and softened while placed over the mold, and deformed to conform to the shape of the mold using vacuum pressure or compressed air pressure. By using a resin material as the spring material in this way, springback, which occurs when a metal plate is used, is less likely to occur, and the shape of each individual can be stabilized. Alternatively, the spring material may be formed by injection molding of the resin material. Furthermore, when the spring material is constructed from resin in this manner, the touch sensors (capacitive sensors) on both sides may be provided as separate components.

[0095] In the above embodiment, a configuration in which most of the front wheel 102 is covered by the wheel cover 105 is illustrated. In a modified example, the wheel cover 105 may be omitted, and the opening may be widened by the front wheel 102. In the above embodiment, a configuration was shown in which most of the front wheel 102 is exposed from the cover 312 when the wheels are driven, but a part of it is placed inside the cover 312. In a modified example, the entire front wheel 102 may be exposed to the outside when the wheels are driven. In that case as well, the portion of the wheel cover 105 near the pivot axis 378 may be placed inside the cover 312.

[0096] In the above embodiment, a configuration in which the robot has wheels as a "mobility mechanism" was illustrated. In a modified example, the "mobility mechanism" may be legs, and the robot may be configured to walk. The drive mechanism drives the legs to move forward and backward from the storage space inside the cover (elastic body, body forming member) to the outside. At this time, as the legs extend, the opening formed between the main frame and the cover, or in the cover itself, is pushed open. As the legs are retracted, the cover elastically returns to its original position and closes the opening.

[0097] Although not mentioned in the above embodiment, the robot may be equipped with a fall detection unit that determines whether it has fallen. This fall detection unit may determine whether it has fallen based, for example, on the value detected by an acceleration sensor. That is, if the robot is determined to have fallen while the wheels have extended out of the cover (elastic body), the drive mechanism may quickly retract the wheels into the cover to absorb the impact when the robot falls to the floor. In particular, in a structure that does not have a shock absorber (spring, etc.) in the wheel support part, as in the above embodiment, damage to the wheels can be prevented or mitigated. Note that wheel retraction control is performed for all wheels, including the front and rear wheels.

[0098] Although not mentioned in the above embodiment, wheel retraction conditions (evacuation conditions) may be set as appropriate. For example, when a user is nearby, the robot may spontaneously retract its wheels, sit down, and make gestures as if asking to be held. Specifically, the condition may be that the robot detects a user within a predetermined distance. Furthermore, the condition may also include that the level of familiarity stored about that user is above a certain threshold.

[0099] Furthermore, storage conditions may be set according to the user's contact patterns, such as when the robot is picked up. Specifically, when both sides of the robot (for example, a pair of protruding parts 512) are touched... The conditions may also include that the object is lifted upwards. The former can be detected by a touch sensor (such as a capacitive sensor made of spring material 514). The latter can be determined based on the detection of an acceleration sensor.

[0100] The retraction condition may include the detection of a fall during or immediately after the wheels are in operation. The robot has a step detection unit (not shown) that detects steps in the floor surface. When the step detection unit detects a step, the robot changes its course to avoid falling over the detected step. However, it is conceivable that if a force exceeding a predetermined amount is applied from outside the robot, such as when the robot is pushed by a child while positioned at a step, the robot may not be able to cope and may fall. In such a case, the fall detection unit may immediately determine that a fall has occurred and retract the wheels based on the detection and determination of the fall.

[0101] The conditions for wheel extension may also be set as appropriate. For example, assuming the robot is placed on the floor, the condition for extension may be that no user is detected within a predetermined distance. The condition may also be that the robot is not being touched by a user (no touch sensors detect contact). Alternatively, the condition may be that a specific part is not being touched by a user (no specific touch sensor detects contact). For example, the condition may be that both sides of the robot (a pair of protruding parts 512, etc.) are not being touched. Furthermore, an additional condition may be added that a predetermined waiting time (set time) has elapsed after such extension conditions are met, and the wheel extension operation may be performed when this additional condition is satisfied. By setting a waiting time in this way, for example, even if the robot is placed in an unstable location and falls over, the wheels remain retracted, preventing unintended loads from being placed on the wheels and damaging them.

[0102] Although not mentioned in the above embodiment, the elasticity of the cover (elastic body) can be set as appropriate. Lowering the elastic modulus of the cover increases the degree of deformation when the wheel moves back and forth, and reduces the opening area when the wheel is exposed. On the other hand, maintaining a high elastic modulus of the cover makes it easier to protect the inner wheel when it is subjected to an external impact. For this reason, when the wheel moves back and forth in the gap between the cover and the main frame, the elastic modulus of the cover on the side closer to the main frame (proximity part) may be set lower than the elastic modulus of the side further away (separation part).

[0103] Although not mentioned in the above embodiment, the surface of the resin material constituting the cover may be covered with a material that feels good to the touch, such as suede fabric.

[0104] Figure 15 is a diagram showing the wheel storage mechanism according to the sixth modified example. Figure 15(a) is a side view showing the structure of the wheel storage section and its surroundings. Figure 15(b) is a cross-sectional view of the wheel storage state seen from the front. As shown in Figure 15(a), this modified example includes a cover 900. The cover 900 includes a first cover 902 and a second cover 904. The first cover 902 has a bulge 512 and is generally bowl-shaped (hemispherical), but its upper end is flat. The rear end of the first cover 902 is fixed to the body frame 318 along its periphery (see dashed-dotted area), but the rest of the first cover, including the upper end, is free. The first cover 902 is fixed in a location where deformation due to the movement of the front wheel 102 is minimal.

[0105] The second cover 904 is positioned above the first cover 902. The second cover 904 is made of a flexible rubber sheet, with its upper half fixed to the body frame 318 (see dashed-dotted area) and its lower half free. The lower part of the second cover 904 overlaps the upper end of the first cover 902, so that it can cover the upper opening of the first cover 902 even when the front wheel 102 moves back and forth and the opening becomes larger. Furthermore, if the material of the second cover 904 is a flexible material that can expand and contract in accordance with the opening state of the upper opening of the first cover 902, Alternatively, the lower part of the second cover 904 may be glued to the upper end of the first cover 902.

[0106] As shown in Figure 15(b), the inner edge (periphery) of the first cover 902 abuts against the side surface of the body frame 318, forming a closed space inside the bulge 512. This closed space functions as the storage space S.

[0107] A spring 910 is interposed between the fuselage frame 318 and the first cover 902. The spring 910 is positioned on the upper front and lower rear sides of the fuselage frame 318 so as not to interfere with the tracks of the front wheel 102 and wheel cover 105. When the front wheel 102 extends, an opening is formed between the peripheral edge (front end and upper end) of the first cover 902 and the fuselage frame 318. Each spring 910 functions as a "biasing mechanism," biasing the first cover 902 toward the fuselage frame 318 (closing the opening between them) (see solid arrow). This makes the opening formed when the front wheel 102 extends smaller.

[0108] Furthermore, communication holes 912 are provided on the left and right sides of the torso frame 318, connecting the inside and outside, and a fan 914 is installed inside the torso frame 318. The communication holes 912 are equipped with filters to prevent foreign matter from entering the inside of the torso frame 318. The fan 914 is used for internal cooling, but when the first cover 902 is closed, it becomes difficult for air to flow in from the outside, and by driving the fan 914, air is drawn in from the housing space S (see dashed arrow). This creates negative pressure in the housing space S, which has the effect of pulling the first cover 902 towards the torso frame 318 (see dashed arrow). As a result, the opening can be closed more securely. The rotation speed of the fan 914 may be increased when the front wheels 102 are retracted or when the robot detects contact with a user. This allows the opening to be closed more reliably.

[0109] In this modified example, the opening is reduced by the biasing force of the spring 910 and the suction force of the fan 914, but one of these may be omitted. Also, although this modified example is applied to a structure similar to that in Figure 11 (a structure in which an opening is formed between the body frame 318 and the first cover 902), it may also be applied to the structure shown in Figure 7 (a structure in which a slit is formed in the cover itself). In that case, the spring should be placed between the body frame and the bulge so as not to interfere with the wheel track.

[0110] Figure 16 is a diagram showing the wheel storage mechanism according to the seventh modified example. Figure 16(a) is a side view showing the structure of the wheel storage section and its surroundings. Figure 16(b) is a side view of the wheel, and Figure 16(c) is a diagram showing the operation of the wheel storage mechanism. As shown in Figure 16(a), in this modified example, the robot has four wheels. The front wheels 922F are the drive wheels, and the rear wheels 922R are the driven wheels. When not specifically distinguishing between the two, they are collectively referred to as "wheels 922". For the sake of explanation, only the left wheel is shown in the figure. The right wheel is connected to the left wheel via an axle that is not shown.

[0111] The wheel 922 is mostly covered by the wheel cover 925, except for the contact surface. The wheel cover 925 is exposed on the side of the body frame 918 and does not move back and forth in relation to the housing space as in the above embodiment. On the other hand, as also shown in Figure 16(b), a housing cover 930 is disposed inside the wheel cover 925. The housing cover 930 is roughly disc-shaped and is rotatably mounted around a rotation axis 932. The axis of the rotation axis 932 coincides with the axis of the wheel 922. The housing cover 930 includes a small diameter portion 934 and a large diameter portion 936 and has a stepped shape in the circumferential direction. The small diameter portion 934 has a smaller radius of curvature than the wheel 922, and the large diameter portion 936 has a larger radius of curvature than the wheel 922. An outer frame portion 938 of a predetermined height extends from the outer peripheral edge of the large diameter portion 936 toward the body frame 918. The height of the outer frame portion 938 is equal to the height of the wheel 922 It is larger than the width.

[0112] As shown in Figure 16(a), the torso frame 918 is provided with an actuator 940. In this modified example, a motor is used as the actuator 940. The motion control unit 152 drives the actuator 940 to rotate the housing cover 930. During normal control, that is, when the robot is able to move, the housing cover 930 is retracted into the wheel cover 925, as shown in Figure 16(b), exposing the wheels 922. On the other hand, when the wheel storage condition is met, the actuator 940 is driven to rotate the housing cover 930 by a predetermined angle (180 degrees in this modified example). As a result, as shown in Figure 16(c), the housing cover 930 covers the wheels 922. The wheel storage condition is defined as detecting a state in which the running surface of the wheels 922 is not in contact with the ground, such as when the robot is lifted, when the wheels 922 are not in contact with the floor, or when the distance between the robot's seating surface (bottom surface) and the floor becomes greater than a predetermined distance. The robot is equipped with a storage condition determination unit (not shown) that uses various sensors to determine whether the robot's state satisfies the wheel storage conditions. The drive mechanism drives the storage cover 930 forward when it is determined that the wheel storage conditions are met. As a result, the storage cover 930 covers the wheels 922. Performing this control when a user picks up the robot avoids problems such as the wheels 922 interfering with the user or soiling their clothes. Note that the wheel storage conditions may also include the storage conditions described above (such as when a fall is detected).

[0113] In this modified version, the structure covers the wheels by moving the cover, so when lowering the robot to the floor, the cover must be retracted before it touches the floor. For this reason, when lowering the robot to the floor from a state where the wheel storage conditions are met, the housing cover 930 is retracted into the wheel cover 925 before the robot touches the floor. For example, the distance between the robot and the floor may be measured using a distance measuring sensor that uses ultrasound or infrared, or it may be measured using a barometer. Furthermore, by using an acceleration sensor in combination with these sensors, it is possible to determine with high accuracy whether the wheels 922 are floating above the floor or are about to touch the floor from a floating state. In this way, the conditions for exposing the wheels (conditions for retracting the housing cover 930) may include the above-mentioned advance conditions (such as the user not touching a specific part, not having fallen, etc.). A posture determination unit may be provided to determine the posture of the robot. When the robot is in a predetermined posture such as being lifted (horizontal or vertical), or in a dropped state, the cover may not be retracted even if the wheels are in contact with an object such as the floor. Furthermore, an interface such as a switch that accepts direct operation from the user may be provided at a specific location on the robot. When the switch is operated, if the wheels are exposed, the housing cover 930 may be extended to cover the wheels 922, and if the wheels are covered, the housing cover 930 may be retracted to expose the wheels 922. In this way, direct operation by the user may also be defined as wheel retraction and extension conditions.

[0114] The modified robot can be described as follows: This robot comprises a body, a moving mechanism having a contact surface when moving, a cover supported by the body so as to be able to extend or retract relative to the moving mechanism and capable of covering the contact surface when driven to extend, a storage condition determination unit that determines whether predetermined storage conditions have been met, and a drive mechanism that drives the cover to extend when the storage conditions are met. The robot is equipped with sensors that can detect at least one of the internal and external states. The storage condition determination unit determines whether the storage conditions have been met based on the detection information of the sensors. The robot may further include a storage maintenance condition determination unit (not shown) that determines whether predetermined storage maintenance conditions have been met. The drive mechanism prohibits the retraction drive of the cover while the storage maintenance conditions are met. The robot may further include a lifting determination unit that determines whether the robot is in a lifted state. The storage maintenance conditions may include the robot being in a lifted state.

[0115] It can also be described as follows: This robot comprises a main frame, a first cover fixed to the main frame, a moving mechanism supported by the main frame so as to be partially exposed from the first cover, a second cover disposed in the space between the first cover and the main frame, and a drive mechanism for moving the second cover forward from or backward into the first cover. When the second cover moves forward, it forms a closed space between itself and the first cover, and the moving mechanism is housed in that closed space.

[0116] In this modified version, the torso frame 918 corresponds to the "main body frame," the wheel cover 925 corresponds to the "first cover," and the wheels 922 correspond to the "movement mechanism." Additionally, the housing cover 930 corresponds to the "second cover," and the actuator 940 corresponds to the "drive mechanism." This modified version solves the problem of preventing or suppressing interference with the movement mechanism when a user touches the robot, such as by picking it up.

[0117] In this modified example, a wheel cover 925 (a fixed cover fixed to the main frame) and a storage cover 930 (a movable cover movably supported by the main frame) are provided, and the entire wheel 922 is housed by both covers as the movable cover extends from the fixed cover. In other modified examples, the fixed cover may be omitted. That is, when the movable cover is retracted, the entire or a part of the wheel (including the contact surface) is exposed, and when the movable cover is extended, the entire wheel may be covered.

[0118] The concept of the above embodiments and modifications can also be understood as the following robot. This robot comprises a body, a moving mechanism having a contact surface when moving, and a cover capable of covering the contact surface of the moving mechanism. The robot comprises a main frame, a cover capable of forming a closed space between itself and the main frame, and a moving mechanism having a contact surface when moving, the contact surface being provided to be housed in the closed space and exposed from the closed space. The robot comprises a drive mechanism. The drive mechanism has at least one of a mechanism for driving the moving mechanism forward and backward from the closed space, and a mechanism for driving the cover forward and backward relative to the moving mechanism. Although not described in the above embodiments and modifications, the configuration may be such that the wheels can be housed in the closed space by combining the retraction drive of the wheels and the extension drive of the cover. By driving both the wheels and the cover when housing the wheels, the amount of drive for each can be reduced. This makes it possible to reduce the space required for housing the wheels in the body and save space in the body.

Claims

1. The main frame and An elastic body that forms a closed space between itself and the main frame, A moving mechanism having a contact surface during movement and being housed within the enclosed space, A drive mechanism for moving the aforementioned moving mechanism to or from the enclosed space, Equipped with, The robot is characterized in that the elastic body elastically deforms in response to the pressing force received as the moving mechanism advances, thereby enlarging the opening for exposing the moving mechanism, and elastically returns to its original state as the moving mechanism retracts, thereby reducing the size of the opening.

2. The elastic body has a curved shape that bulges out in a direction away from the main frame and forms the closed space inward. The robot according to claim 1, characterized in that the curved shape changes as the moving mechanism moves from the inside to the outside of the enclosed space.

3. The robot according to claim 1 or 2, characterized in that the opening is formed between the peripheral edge of the elastic body facing the main body frame and the main body frame.

4. The robot according to any one of claims 1 to 3, characterized in that it is provided with a biasing mechanism that biases the elastic body in the direction of closing the opening.

5. The aforementioned moving mechanism has wheels and wheel covers, The robot according to any one of claims 1 to 4, characterized in that when the moving mechanism moves forward, the wheel cover comes into contact with and expands the opening of the elastic body.

6. The robot according to claim 5, characterized in that the wheel cover has an outer surface with a shape complementary to the inner surface of the elastic body.

7. The robot according to any one of claims 1 to 6, characterized in that the elastic body includes a spring material as a core material and a resin material in which the spring material is attached or inserted.

8. The robot according to claim 7, characterized in that the spring material has a frame structure provided in accordance with the shape of the resin material.

9. The resin material has a shape that bulges out in a direction away from the main frame, The robot according to claim 7 or 8, characterized in that the spring material has a curved shape that conforms to the shape of the resin material.

10. The robot according to any one of 7 to 9, characterized in that the spring material consists of a metal plate that functions as a capacitance sensor.

11. The robot according to any one of claims 1 to 10, characterized in that the opening is a slit provided in the elastic body on the trajectory of the moving mechanism.

12. The robot according to any one of claims 1 to 11, characterized in that the elastic body together with the main frame forms the body of the robot.

13. The robot is equipped with a fall detection unit that determines whether the robot will fall, The drive mechanism is determined to have fallen when the moving mechanism has moved out of the enclosed space. The robot according to any one of claims 1 to 12, characterized in that the moving mechanism is retracted into the closed space when this occurs.

14. The body and A body forming member that constitutes a part of the body and has an internal storage space, A moving mechanism having a contact surface for movement and being provided so as to be housed in the aforementioned storage space, A drive mechanism for moving the aforementioned moving mechanism out of the housing space and to the outside, Equipped with, The robot is characterized in that the body forming member has a flexible portion that forms an opening that is expanded as the moving mechanism advances.

15. The robot according to claim 14, characterized in that the body forming member generates a biasing force in the direction of closing the opening when the opening is pushed open.

16. The body and A moving mechanism having a contact surface during movement, A cover that is supported by the aforementioned moving mechanism so as to be able to extend or retract, and which can cover the ground surface when driven to extend, A storage condition determination unit that determines whether or not predetermined storage conditions have been met, When the aforementioned storage conditions are met, a drive mechanism drives the cover to extend, A robot characterized by being equipped with the following features.

17. It further includes a storage maintenance condition determination unit that determines whether or not predetermined storage maintenance conditions are met, The aforementioned drive mechanism is The robot according to claim 16, characterized in that the retraction drive of the cover is prohibited while the aforementioned storage maintenance conditions are met.

Images