WO2019140568A1

WO2019140568A1 - Child companion robot

Info

Publication number: WO2019140568A1
Application number: PCT/CN2018/072993
Authority: WO
Inventors: 冯继斌; 张鸿阳; 王婧文; 黄亮; 法比奥·圣阿加塔
Original assignee: 深圳市共进电子股份有限公司
Priority date: 2018-01-17
Filing date: 2018-01-17
Publication date: 2019-07-25

Abstract

A child companion robot, comprising an upper part (100), a trunk (200), a lower part (300), and a bottom part (400) which are connected in sequence. The upper part (100) comprises a head part (100H) and a neck part (100N); the head part (100H) and the neck part (100N) drive the upper part (100); the trunk (200) comprises a chest part (200C) and a waist part (200W); the chest part (200C) and the waist part (200W) drives the trunk (200); the lower part (300) comprises a hip part (300K); the bottom part (400) comprises a leg part (400B); the head part (100H), the neck part (100N), the chest part (200C), the waist part (200W), the hip part (300K), and the leg part (400B) are connected in sequence to enable the head part (100H), the neck part (100N), the chest part (200C), the waist part (200W), and the hip part (300K) to have at least one degree of freedom of motion. The child companion robot is easy to control and low in cost, and a system is easy to be constructed; the structure is simple while multiple degrees of freedom of the robot can be guaranteed, and flexible limb movement can be realized.

Description

Child companion robot

Technical field

The invention relates to the field of robots, and in particular to a child companion robot.

Background technique

At present, robots are widely used in various industries, whether it is military, manufacturing, aerospace, education, entertainment, medical care, disaster relief, family services and social services, robots can play a pivotal role. With the growing number of dual-employee families, more and more children lack the necessary companionship and enlightenment education during their early growth. This has made the demand for emotional companionship and early education family service robots more and more popular.

With the development of artificial intelligence technology, the interactive experience of robots will become smarter and more emotional. Most of the companion robots in the prior art pay attention to the intelligence and emotionalization of the voice interaction, but neglect the anthropomorphization of the robot body structure, the limb movement is limited, and the action is rigid. This is because companion robots usually have an adult-like appearance to attract attention, but the human body structure is very complicated. If you copy and imitate the joints of the human body's arms and legs, you need a lot of motors, which are costly and complicated to control. Not too compact.

Summary of the invention

The object of the present invention is to solve the technical problem that the limb movement is limited and the action is rigid in the prior art, and a child companion robot is proposed.

In order to solve the above technical problems, the present invention adopts the following technical solutions:

a child companion robot comprising an upper portion, a torso, a lower portion and a bottom portion connected in series; the upper portion including a head portion and a neck portion, the head portion and the neck portion driving the upper portion; the torso comprising a chest and a waist, The chest and the waist drive the torso; the lower portion includes a hip; the bottom includes a leg; the head, the neck, the chest, the waist, the hip, and the leg The portions are sequentially connected such that the head, the neck, the chest, the waist, and the hip each have at least one degree of freedom of movement.

In some preferred embodiments, the manner of connection between the head, the neck, the chest, the waist, the hip, and the leg includes one or more of the following: a rotational connection , translational connection or vibration connection.

In a further preferred embodiment, the rotational connection is achieved by a pulley and a timing belt, the pulley being coupled to the timing belt, the pulley and the timing belt being driven by a motor.

In some preferred embodiments, the direction of movement between the head, the neck, the chest, the waist, the hip, and the leg are different.

In some preferred embodiments, the connection between the head, the neck, the chest, the waist, the hip, and the leg is a rotational connection; the head of the head a first angle between an axis of the rotation direction and an axis of the neck rotation direction of the neck; a second angle between the axis of the neck rotation direction and the axis of the chest rotation direction of the chest a third angle between the axis of the chest rotation direction and the axis of the waist rotation direction of the waist; the axis of the waist rotation direction and the axis of the hip rotation direction of the hip are the fourth Angle.

In some preferred embodiments, a nested connection between the head and the neck; a nested connection between the chest and the waist; between the waist and the hip For nested connections.

In a further preferred embodiment, the leg carries the hip, the waist is nested inside the hip, the chest is nested inside the waist, and the neck is nested in The inside of the head.

In some preferred embodiments, the leg includes a large pulley, a fixed disc and a bottom timing belt; the hip includes a hip small pulley; the large pulley is mounted on the fixed disc, The large pulley is coupled to the hip small pulley through the bottom timing belt.

In some preferred embodiments, the waist portion includes a waist timing belt and a waist large belt pulley; the hip portion includes a waist small pulley; the waist large pulley is coupled to the waist timing belt, the waist timing belt Connected to the waist small pulley.

In a further preferred embodiment, a tensioning wheel is also included, the tensioning wheel being used to adjust the wrap angle of the timing belt.

Compared with the prior art, the beneficial effects of the present invention are:

The invention simulates the structure of the human body, and drives the upper part, the trunk, the lower part and the bottom part through six human body structures. The upper part is mainly driven by the head and the neck, the trunk is mainly driven by the chest and the waist, and the lower part is driven by the hip. The six human body structures of the head, neck, chest, waist, hips and legs are connected in turn, which are mechanical structures in series, which facilitates linkage and achieves at least five degrees of freedom. On the whole, the upper part and the trunk each have at least two degrees of freedom of movement, and the lower part has a degree of freedom of movement, which enables flexible and complex body movements, such as dancing, so that the robot can better accompany the child.

In addition, the movements of the six human structures are reflected by the upper part, the trunk and the lower part. The compact structure and the mechanical structure of the series make the whole child companion robot easy to control, and the system is easy to set up, thereby reducing the cost.

In a preferred embodiment, the present invention also has the following beneficial effects:

Further, the connection between the head, neck, chest, waist, hips and legs of the six human body structures is nested, making the structure of the robot more compact.

DRAWINGS

1 is a schematic view showing the overall structure of a child companion robot of the present invention;

2 is a schematic view showing the internal structure of a child companion robot of the present invention;

Figure 3 is an exploded view of the internal structure of the child companion robot of the present invention;

Figure 4 is an exploded perspective view showing the leg of the child companion robot of the present invention;

Figure 5 is a structural exploded view of the hip of the child companion robot of the present invention;

Figure 6 is a structural exploded view of the waist of the child companion robot of the present invention;

Figure 7a is a structural exploded view of the chest of the child companion robot of the present invention;

Figure 7b is a structural schematic view of another angle of the area A of Figure 7a;

Figure 8 is a structural exploded view of the neck of the child companion robot of the present invention;

Figure 9 is an exploded perspective view of the head of the child companion robot of the present invention.

Detailed ways

Embodiments of the invention are described in detail below. It is to be understood that the following description is only illustrative, and is not intended to limit the scope of the invention.

1 to 3, the child companion robot includes an upper portion 100, a torso 200, a lower portion 300, and a bottom portion 400. The upper portion 100 includes a head portion 100H and a neck portion 100N, the torso 200 includes a chest portion 200C and a waist portion 200W, and the lower portion 300 includes a hip portion 300K. The bottom portion 400 includes a leg portion 400B, and the head portion 100H, the neck portion 100N, the chest portion 200C, the waist portion 200W, the hip portion 300K, and the leg portion 400B are sequentially connected such that the head portion 100H, the neck portion 100N, the chest portion 200C, the waist portion 200W, and the hip portion 300K have At least one degree of freedom of movement. Of course, the upper portion 100, the torso 200, the lower portion 300, and the bottom portion 400 each include a respective outer casing (not shown).

Referring to FIGS. 1 through 3, the present invention simulates a human body structure, and drives an outer upper portion 100, a trunk 200, a lower portion 300, and a bottom portion 400 by six large human body structures disposed inside the robot. The upper portion 100 is mainly composed of a head portion 100H and a neck portion 100N. Driven, the torso 200 is primarily driven by the chest 200C and the waist 200W, and the lower portion 300 is driven by the hip 300K. The six human body structure heads 100H, neck 100N, chest 200C, waist 200W, hip 300K and leg 400B are connected in series, which are mechanical structures in series, which facilitates linkage and achieves at least five degrees of freedom. Overall, the upper portion 100 and the torso 200 each have at least two degrees of freedom of movement, and the lower portion 300 has a degree of freedom of movement, enabling flexible and complex body movements, such as dancing, so that the robot can better Accompany children.

The manner of connection between the head 100H, the neck 100N, the chest 200C, the waist 200W, the hip 300K, and the leg 400B includes one or more of the following: a rotational connection, a translational connection, or a vibrational connection. From the perspective of imitating human motion with a simple structure, it is better to use a rotational connection because the movement of the human body is mostly carried out around the joint. The movement of the human body is mainly based on rotation, and the rotational connection can be better. Imitate human movement.

The working principle of the present invention will be further described below in conjunction with a rotary connection:

Referring to FIG. 1 to FIG. 3, specifically, the structure of the child companion robot can be set as follows: from the inside of the robot, the chest 200C rotates to drive the head 100H and the neck 100N, and the waist 200W rotates to drive the head 100H, the neck 100N, and the chest. 200C, the hip 300K rotation drives the head 100H, the neck 100N, the chest 200C and the waist 200W; the leg 400B is placed on a horizontal surface, and can be set to be movable or not moving according to actual use. In this way, the hip 300K rotates to drive the head 100H, the neck 100N, the chest 200C and the waist 200W to rotate, and the head 100H, the neck 100N, the chest 200C and the waist 200W can be separately rotated at the same time, and the child companion robot can realize linkage. This linkage is seen from the outside of the robot. The lower portion 300 drives the torso 200 and the upper portion 100 to rotate, and the torso 200 itself has at least two degrees of rotational freedom. Thus, the torso 200 can be rotated by the lower portion 300, and the torso 200 itself can also be rotated. Rotate in at least two directions to superimpose the rotational motion to achieve a variety of motions, and the robot can better mimic human motion. The same is true for the upper portion 100. The lower portion 300 and the torso 200 can be simultaneously driven to cause more rotational motion to be superimposed, thereby better mimicking the movement of the human body.

Of course, the structure of the child companion robot can also have other settings, such as: the chest 200C rotation drives the neck 100N, the waist 200W rotation drives the chest 200C, the hip 300K rotation drives the chest 200C and the waist 200W, the invention is not limited thereto.

In order to imitate as much human motion as possible through a simple structure, the movement directions of the six major human body heads 100H, neck 100N, chest 200C, waist 200W, hip 300K, and leg 400B are different, specifically The movement directions of the six human structures may be different or partially the same. Taking the rotational connection as an example to illustrate how to set: the first angle between the axis of the head rotation direction of the head 100H and the axis of the neck rotation direction of the neck 100N; the axis of the neck rotation direction and the chest of the chest 200C a second angle between the axes of the rotational direction; a third angle between the axis of the chest rotation direction and the axis of the waist rotation direction of the waist 200W; an axis of the waist rotation direction and an axis of the hip rotation direction of the hip 300K Between the fourth angle. Referring to FIG. 2, more specifically, in order to closely simulate the movement of the human body, the axis of the head rotation direction of the head 100H is parallel or approximately parallel to the horizontal plane to lift and lower the upper portion 100; the neck rotation direction of the neck 100N The axis is parallel or approximately parallel to the vertical direction to achieve rotation of the upper portion 100; the axis of the chest rotation direction of the chest 200C is parallel or nearly parallel to the horizontal plane and perpendicular or approximately perpendicular to the axis of the head rotation direction to achieve the left and right swinging torso 200 The axis of the lumbar rotation direction of the waist 200W is parallel or nearly parallel to the horizontal plane and is perpendicular or approximately perpendicular to the axis of the chest rotation direction to achieve the forward and backward torso 200; the axis and the vertical direction of the hip rotation direction of the hip 300K Parallel or approximately parallel to achieve rotation of the torso 200.

The present invention has been described above, but the present invention may also have some variants, such as:

The connection between the head 100H, the neck 100N, the chest 200C, the waist 200W, the hip 300K and the leg portion 400B is connected by a translational connection to achieve telescopic or left and right movement;

The connection between the head 100H, the neck 100N, the chest 200C, the waist 200W, the hip 300K and the leg 400B is connected by vibration to achieve vibration or oscillation;

The connection between the head 100H, the neck 100N, the chest 200C, the waist 200W, the hip 300K and the leg 400B is a combination of a rotational connection, a translational connection or a vibration connection, such as between the head 100H and the neck 100N. In addition to the rotary connection, a translational connection is also used. The head 100H can be rotated and telescoped, so that the head has multiple degrees of freedom of movement, and other parts can also be arranged in this way.

Referring to Fig. 1, the movements of the six large human structures are represented by the upper portion 100, the torso 200, and the hip portion 300. The compact structure and the mechanical structure in series make the entire child companion robot easy to control, thereby reducing costs.

Referring to Figures 2 and 3, in order to make the structure more compact, the connections between the six human structures are nested. Specifically, there is a nested connection between the head 100H and the neck 100H, a nested connection between the chest 200C and the waist 200W, and a nested connection between the waist 200W and the hip 200K. This nested connection allows one mechanism to enclose or semi-enclose another mechanism, allowing the overall structure to be gathered, resulting in a more compact structure.

Specifically, in the present invention, the leg portion 300B carries the hip portion 300K, the waist portion 200W is nested inside the hip portion 300K, the chest portion 200C is nested inside the waist portion 200W, and the neck portion 100N is nested inside the head portion 100H. Of course, there may be other nested connections according to actual needs. For example, the hip 300K is nested inside the waist 200W, and the waist 200W is nested inside the chest 200C. The present invention is not limited thereto.

In the present invention, the rotational connection is realized by a pulley and a timing belt, and the pulley is connected to the timing belt, and the pulley and the timing belt are driven by the motor. The use of synchronous pulleys and stepper motors. A tensioning wheel can also be provided for adjusting the wrap angle of the timing belt. Driven by a stepper motor, the synchronous belt pulley is used to transmit motion, and the tensioning pulley is used to increase the timing of the timing belt wrap angle, so that the robot has a smooth speed and less noise during the movement.

The specific structure of the head 100H, the neck 100N, the chest 200C, the waist 200W, the hip 300K, and the leg 400B is further described below:

Referring to FIG. 4, the leg portion 300B includes a chassis B8, a fixed bracket B7, a fixed disc B6, a bearing inner end cover B5, a bearing outer end cover B4, a ball bearing B3, a large pulley B2, a bottom timing belt B1, and a fixed bracket B7 installation. On the chassis B8; the fixed disc B6 is mounted on the fixed bracket B7; the bearing inner end cover B5 is mounted on the extension shaft (not shown) in the middle of the hip chassis K7; the bearing outer end cover B4 is fixed in the large belt On the wheel B2; the ball bearing B3 is installed between the large pulley B2 and the bearing outer end cover B4; the large pulley B2 is mounted on the fixed disc B6, and is driven by the bottom synchronous belt B1 and the hip small pulley K9, The pulley B2, the bottom timing belt B1, and the hip small pulley K9 constitute a joint between the hip portion 300K and the leg portion 300B, and the rotational connection of the hip portion 300K and the leg portion 300B is achieved.

Referring to FIG. 5, the hip portion 300K includes a tensioning bracket K1, a hip tensioning pulley K2, a pulley fixing bracket K3, a lumbar driving motor fixing plate K4, a waist small pulley K5, a lumbar driving motor K6, a hip chassis K7, and a hip. Drive motor fixing plate K8, hip small pulley K9, hip drive motor K10, bearing holder K11; tension bracket K1 for fixing the hip tensioner K2, mounted on the pulley holder K3; pulley The fixing frame K3 is mounted on the hip chassis K7; the waist driving motor fixing plate K4 is mounted on the pulley fixing frame K3 for fixing the waist driving motor K6; the waist driving motor K6 is mounted on the pulley fixing by the waist driving motor fixing plate K4. On the frame K3; the hip chassis K7 and the bottom 300B are connected by bearings (not shown); the hip drive motor fixing plate K8 is mounted on the hip chassis K7; the hip drive motor K10 is driven by the hip drive motor plate K8 Mounted on the hip chassis K7; the bearing holder K11 is mounted on the hip chassis K7 for fixing the support bearing W15 of the hip 300K connected to the waist 200W.

Referring to Fig. 6, the waist portion 200W includes a waist timing belt W1, a waist large belt wheel W2, a pulley bearing W3, a pulley bearing outer end cover W4, a pulley bearing inner end cover W5, a chest support frame W6, a chest fixing frame W7, and a chest. Drive motor fixing plate W8, chest tensioner W9, chest tensioning bracket W10, chest drive motor W11, chest small pulley W12, support bearing inner end cover W13, support bearing outer end cover W14, support bearing W15, lumbar support bracket W16; waist timing belt W1 is used for the transmission of the waist 200W, one end is connected to the waist large pulley W2, the other end is connected with the waist small pulley K5 installed on the hip 300K; the pulley bearing W3 is installed inside the waist large pulley W2 The pulley bearing outer end cover W4 is used to fix the outer diameter of the pulley bearing W3; the pulley bearing inner end cover W5 is used to fix the inner diameter of the pulley bearing W3; the chest support frame W6 is used to support the chest part; the chest fixing bracket W7 For fixing the chest part; the chest drive motor fixing plate W8 is used for fixing the chest drive motor W11, and is mounted on the chest fixing frame W7; the chest tensioning wheel W9 is used for increasing the transmission wrap angle of the chest large pulley C14, through the chest piece Tight bracket W10 is mounted on the chest On the frame W7; the chest tensioning bracket W10 is used for fixing the chest tensioning wheel W9, and is mounted on the chest fixing frame W7; the chest driving motor W11 is mounted on the chest fixing frame W7 by the chest driving motor fixing plate W8; the chest small pulley W12 Mounted on the chest drive motor W11 for transmitting chest motion; the support bearing inner end cover W13 is used to fix the inner diameter of the pulley bearing W3, and is mounted on the lumbar support bracket W16; the support bearing outer end cover W14 is used for fixing the support bearing W15 The outer diameter is mounted on the chest mount W7; the support bearing W15 is used to support the waist 200W movement, and is mounted between the support bearing outer end cover W14 and the lumbar support bracket W16; the lumbar support bracket W16 is used to fix the support bearing W15, and It is connected to the chest support frame W6 and the chest fixing frame W7 by screws; the waist large pulley W2 is used for driving the waist drive motor K6, and is connected with the waist timing belt W1, and the waist timing belt W1 is connected with the waist small pulley K5, and the waist timing belt W1, the waist large pulley W2 and the waist small pulley K5 form a joint between the waist 200W and the hip 300K, and realize the rotational connection of the waist 200W and the hip 300K.

Referring to Figures 7a and 7b, the chest 200C includes a neck drive motor C1, a neck small pulley C2, a neck drive motor fixing plate C3, a housing support frame C4, a housing support frame C5, and a neck drive motor mount C6. , chest mount C7, chest support bearing C8, support bearing outer end cap C9, support bearing inner end cap C10, pulley bearing inner end cap C11, pulley bearing outer end cap C12, pulley bearing C13, chest large pulley C14, chest timing belt C15; neck driving motor C1 is used to drive the neck 200N, and is mounted on the neck driving motor fixing frame C6 through the neck driving motor fixing plate C3; the neck small pulley C2 is mounted on the neck driving motor C1; the outer shell support frame C4 and the outer shell support frame C5 are used for connecting the fixed outer casing body, and are mounted on the neck drive motor fixing bracket C6; the chest fixing frame C7 is used for fixing the chest part and is mounted on the chest support frame W6; The chest support bearing C8 is used to assist the support of the chest part; the support bearing outer end cover C9 and the support bearing inner end cover C10 are respectively used to fix the outer diameter and the inner diameter of the chest support bearing C8; the pulley bearing outer end cover C12 and the pulley bearing are respectively End cap C11 is used respectively The outer diameter and inner diameter of the fixed pulley bearing C13; the pulley bearing C13 is mounted between the large pulley C14; the chest large pulley C14 is mounted on the chest fixing frame C7, and the chest large pulley C14 is used for the chest driving motor W11. The transmission is connected with the chest synchronous belt C15, the chest synchronous belt C15 is connected with the chest small pulley W12, the chest large pulley C14, the chest synchronous belt C15 and the chest small pulley W12 constitute the joint between the chest 200C and the waist 200W, realizing the chest The 200C is connected to the rotation of the waist 200W.

Referring to Fig. 8, the neck 100N includes a head drive motor mount N1, a head drive motor N2, a head drive motor fixing plate N3, a neck support frame N4, a neck pulley bearing inner end cover N5, and a neck pulley. Bearing outer end cap N6, neck pulley bearing N7, neck pulley N8, neck timing belt N9; head drive motor mount N1 for fixing head drive motor N2, head drive motor mount N1 lower end The neck support frame N4 is connected, and the upper end is used for connecting the head part; the head drive motor N2 is used to drive the head 100H, and the head drive motor fixing plate N3 is mounted on the head drive motor mount N1; the neck support Rack N4 is used to support and connect neck 100N and head parts; neck pulley bearing inner end cap N5 and neck pulley bearing outer end cap N6 are used to fix neck pulley bearing N7; neck pulley bearing N7 Installed in the neck pulley N8; the neck support frame N4 is connected to the neck pulley N8, the neck pulley bearing outer end cover N6 is mounted on the neck pulley N8, and the neck pulley bearing inner end cover N5 is mounted On the neck drive motor mount C6, the neck pulley bearing N7; the neck pulley N8 is used for the neck drive motor C1 Move, connected with the neck synchronous belt N9, the neck timing belt N9 is connected with the neck small pulley C2, the neck pulley N8, the neck timing belt N9 and the neck small pulley C2 constitute the neck 200N and the chest 200C The joint between the necks 200N and the chest 200C.

Referring to Figure 9, the head 100H includes a head pulley bearing inner end cover H1, a head pulley bearing outer end cover H2, a head pulley bearing H3, a head pulley H4, a head timing belt H5, and a head support. H6, head support bearing H7, head support bearing outer end cover H8, head support bearing inner end cover H9; head pulley bearing inner end cover H1 and head pulley bearing outer end cover H2 for fixing head The pulley bearing H3, the head pulley bearing H3 is mounted in the head pulley H4; the head pulley H4 is used for driving the head driving motor N2, connected to the head timing belt H5, and the head timing belt H5 and The pulley connection of the head drive motor N2, the head pulley H4, the head timing belt H5 and the pulley of the head drive motor N2 constitute a joint between the head 100H and the neck 100N, realizing the head 100H and the neck 100N rotary connection.

The above is a further detailed description of the present invention in combination with specific/preferred embodiments, and it is not intended that the specific embodiments of the invention are limited to the description. It will be apparent to those skilled in the art that <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; It belongs to the scope of protection of the present invention.

Claims

a child companion robot comprising: an upper portion, a trunk, a lower portion and a bottom portion connected in series; the upper portion including a head portion and a neck portion, the head portion and the neck portion driving the upper portion; the torso comprising a chest and a waist, the chest and the waist drive the torso; the lower portion includes a hip; the bottom portion includes a leg; the head, the neck, the chest, the waist, the hip The legs are sequentially connected such that the head, the neck, the chest, the waist, and the hip each have at least one degree of freedom of movement.
The child companion robot according to claim 1, wherein a connection between the head, the neck, the chest, the waist, the hip, and the leg includes the following One or more: rotary connection, translational connection or vibration connection.
A child companion robot according to claim 2, wherein said rotational connection is realized by a pulley and a timing belt, said pulley being coupled to said timing belt, said pulley being driven by said motor and said timing belt .
The child companion robot according to claim 1, wherein a direction of movement between said head, said neck portion, said chest portion, said waist portion, said hip portion and said leg portion is different .
The child companion robot according to claim 1, wherein a connection between the head, the neck, the chest, the waist, the hip, and the leg is a rotational connection a first angle between an axis of the head rotation direction of the head and an axis of the neck rotation direction of the neck; an axis of the neck rotation direction and an axis of the chest rotation direction of the chest a second angle; a third angle between the axis of the chest rotation direction and the axis of the waist rotation direction; the axis of the waist rotation direction and the hip rotation direction of the hip The axis is at a fourth angle.
The child companion robot according to claim 1 or 4, wherein a nested connection between the head and the neck is provided; a nested connection between the chest and the waist; A nested connection between the waist and the hip is described.
The child companion robot according to claim 6, wherein said leg portion carries said hip portion, said waist portion is nested inside said hip portion, and said chest portion is nested inside said waist portion, The neck is nested inside the head.
A child companion robot according to claim 1, wherein said leg portion includes a large pulley, a fixed disc and a bottom timing belt; said hip portion includes a hip small pulley; said large pulley is mounted at The large pulley is coupled to the hip small pulley through the bottom timing belt.
A child companion robot according to claim 1, wherein said waist portion includes a waist timing belt and a waist large pulley; said hip portion includes a waist small pulley; said waist large pulley and said waist timing belt Connected, the waist timing belt is coupled to the waist small pulley.
A child companion robot according to claim 3, further comprising a tensioning wheel for adjusting a wrap angle of said timing belt.