JP7397425B2 - Action expression mechanism - Google Patents

Description

The present invention relates to a motion expression mechanism used for a motion body having a large number of joints, such as a humanoid robot.

Bunraku dolls have been known as dolls with movements that appeal to human imagination. Bunraku dolls are used in Bunraku, a traditional Japanese performing art, and are capable of special expressions such as expanding and contracting arms, necks, and bodies. For this reason, even though the movements are not seen in real humans, by exaggerating the movements, it is possible to impressively convey emotions, etc. to the other person.

In recent years, attention has been paid to the movements of Bunraku dolls, and attempts have been made to realize the movements of Bunraku dolls with robots (for example, see Patent Document 1). According to this robot, for example in the nursing care industry, it is possible to provide daily life support while maintaining affinity with people through rich emotional expression.

Japanese Patent Application Publication No. 2016-144545

However, although the above-mentioned robots are able to express rich emotions by exaggerating their movements, the expression of emotions is not yet sufficient and there is still room for improvement. Additionally, there were issues such as the fact that the delicate proportions of humans, such as the suppleness of women, could not be reproduced very well.

An object of the present invention is to provide a motion expression mechanism that can reproduce delicate human proportions as well as rich emotional expression through exaggerated motion.
By the way, the motion expression mechanism according to the present invention was inspired by the above-mentioned Bunraku dolls. For this reason, I will next briefly explain Bunraku dolls. Bunraku dolls are made up of a neck, a wig, a costume, limbs, a torso, and props. Figure 9 shows an example of the neck, torso, and limbs of a Bunraku doll, with markers for motion capture attached to the neck. When these are combined, they form a doll that resembles a human. Bunraku dolls have a relatively thick costume made of cotton that connects the neck and limbs, and the costume can flexibly deform, allowing the doll to take on a variety of postures. ing. The movements of the doll's neck and right hand are precisely controlled by the master's left and right hands, respectively, but the parts corresponding to the doll's shoulders and upper arms are controlled by the weight of the costume and the position and angle of the neck and hands. , the shape is created passively by adjusting the force of pulling or pushing. Although it differs from doll to doll, the human body from the ribs to the knees is passively shaped by the positional relationship and angle of the neck and legs in the same way.

Because Bunraku dolls have this special degree of freedom, it is possible to express things like the arms extending and contracting, the neck extending and contracting, and the torso extending and contracting. When used, it appears as an exaggerated movement expressing emotion. The neck is fitted into a groove drilled in the center of the member corresponding to the shoulder in Figure 9, and uses the round hole at the tip of this groove as a reference point to perform pitch, roll, yaw, and expansion/contraction movements. It can be realized. Furthermore, there is a play between this round hole and the neck support, so that slight movement forward, backward, left, and right relative to the plane that connects both shoulders can occur, or can be caused intentionally. There is. This play seems to produce movements that are truly human-like.

The puppeteer is usually made up of three people, with the main puppeteer in charge of the neck and right hand, the left puppeteer in charge of the left hand, and the foot puppeteer in charge of both legs. In Figure 10, markers are attached to the puppets for movement research, and the left-handed and foot-handed puppets are also performed without a hood. The structure is such that the distance between the doll's joints can be changed depending on the relative position of the hands of the main handler and the relative positions of the three hands. On the other hand, if the three people are not in perfect sync with each other, the doll's posture and movements cannot be achieved.

The master handler holds the puppet's neck with his left hand and controls the puppet's right hand with his right hand. He also uses the knuckles of his left hand to change the relative angle and position of his shoulder plate and neck. In Figure 10, the puppets are shown floating in the air, but in an actual Bunraku stage, a board called a handrail is installed, and the top of this board is used as the ground for the puppets. It is played. When a Bunraku puppet sits or stands, or when its torso expands and contracts, there is a limit to the vertical movement of the main performer's left arm, and rather the impression is that the legs extend downward. However, in order to approximate the shape of a human, the robot according to the present invention needs to be able to extend and contract its torso, while also being able to bend its legs and knees and hip joints based on the actual ground. For this reason, the torso must be expanded and contracted from the waist up, and a mechanism must be designed in which the upper body moves up and down by bending the knees.

The motion expression mechanism of the present invention is
A motion expression mechanism used for a motion body having multiple joints,
placed on the neck, chest, and waist of the operating body,It has at least three degrees of freedom around the pitch axis, roll axis, and yaw axis.RuDegrees of freedom componentand,
a link portion located between the chest and the waist;
an arm connected to the link;
characterized by comprising.

This makes it possible to reproduce rich emotional expressions through exaggerated movements that are not present in real humans, as well as delicate human proportions . In addition, when viewed from the front, it is possible to reproduce subtle proportions that appeal to femininity, such as drawing an S-shape.
In addition, by connecting the arms between the chest and waist, we can reduce the mass of the trunk (body part excluding the arms), lower the height of the center of gravity, and reduce the amount of moment required by the actuators in the waist and chest. Not only can this be significantly reduced, but it also makes it easier to increase the output of the motor that drives the degree of freedom in the arms, making it possible to vibrate the upper body and arms at a faster frequency, making it possible to vibrate small movements such as when crying, for example. It is possible to reproduce movements more exaggerated than they actually are .

Furthermore, the motion expression mechanism of the present invention is
It is characterized in that the neck portion is disposed shifted toward the front side or the back side with respect to the chest portion.

This allows the robot to maintain a well-balanced posture that differs from that of a real human, creating the feeling of floating.
Furthermore, the motion expression mechanism of the present invention is
The chest is characterized in that it includes a chest link that expands and contracts in the vertical direction.

This allows human motion to be deformed and exaggerated.
Furthermore, the motion expression mechanism of the present invention is
The neck portion is characterized in that it includes a neck link portion that expands and contracts in the vertical direction.

This allows human motion to be deformed and exaggerated .

Furthermore, the motion expression mechanism of the present invention is
It is characterized by comprising a slide mechanism that slides the neck back and forth.
This makes it possible to realistically create the atmosphere of a conversation. In addition, by allowing the head to move forward and backward, it is possible to realistically achieve not only an S-shaped proportion but also the functional beauty of a human being.

According to the present invention, it is possible to provide a motion expression mechanism that can reproduce delicate human proportions as well as rich emotional expression through exaggerated motion.

FIG. 3 is a perspective view of the motion expression mechanism according to the embodiment in a state where the link portion is not extended, viewed from above. FIG. 3 is a perspective view of the motion expression mechanism according to the embodiment in a state where the link portion is extended, viewed from above. 1 is a front view of a robot using a motion expression mechanism according to an embodiment; FIG. 1 is a side view of a robot using a motion expression mechanism according to an embodiment; FIG. FIG. 3 is a conceptual diagram for explaining a case where a motion drawing a figure-eight trajectory is realized in the motion expression mechanism according to the embodiment. FIG. 7 is a perspective view of a motion expression mechanism according to another embodiment viewed from above. FIG. 7 is a perspective view of a motion expression mechanism according to another embodiment viewed from above. FIG. 7 is a perspective view of a motion expression mechanism according to another embodiment viewed from above. This photo shows the neck of a Bunraku doll with markers for motion capture, and the torso and limbs of the Bunraku doll. Markers were attached to the bunraku puppets to study their movements, and the left-hander and foot-player were seen performing Bunraku without wearing hoods.

Hereinafter, a motion expression mechanism according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the motion expression mechanism according to the embodiment viewed from above. In the following description, an XYZ orthogonal coordinate system is set, and the description will be made with reference to this XYZ orthogonal coordinate system. In the XYZ orthogonal coordinate system, as shown in FIG. 1, the XY plane is set to be parallel to the horizontal plane on which the motion expression mechanism 2 is placed, and the Z axis is set in the vertically upward direction. In the following description, when representing rotation, the X axis is set as a roll axis, the Y axis is set as a pitch axis, and the Z axis is set as a yaw axis. When explaining rotation, terms such as around a roll axis, around a pitch axis, and around a yaw axis will be used.

As shown in FIG. 1, the motion expression mechanism 2 is a humanoid mechanism that is a motion body having a plurality of joints, and has a plurality of degree-of-freedom components (a head 4, a neck 6, a chest 8, an arm 10, waist part 12, knee part 14, and foot part 16) and link parts (first link part 22, second link part 24, third link part 26, and fourth link part 28) that connect these degree-of-freedom constituent parts. ).

Here, for example, a metal square pipe material is used for the link portion. Further, in the joint portion included in the degree of freedom configuration section, rotation in the direction of the degree of freedom is realized using a motor. If the joints of the trunk (the body part excluding the arms 10) are each composed of multiple motors, the motors can be arranged so that their output axes are orthogonal to each other at one point, so that the joints can move without the discomfort of a joint. can be expressed.

The head 4 is a joint made up of two motors that rotate in orthogonal directions in the XY plane, and can rotate around a roll axis and a pitch axis. That is, the head 4 has two degrees of freedom: rotation around the roll axis and rotation around the pitch axis.

The neck part 6 includes a neck joint part 6a made up of three motors that rotate in directions orthogonal to each other in the XYZ space, and a neck link part 6b that supports the head 4 and can expand and contract in the Z-axis direction. There is. That is, the neck portion 6 has four degrees of freedom: rotation around the roll axis, around the pitch axis, around the yaw axis, and expansion and contraction in the Z-axis direction. The expansion and contraction of the neck link portion 6b is realized by a known technique such as, for example, arranging a small-diameter square pipe within a large-diameter square pipe and sliding it in the Z-axis direction. Furthermore, the output shafts of the three motors are orthogonal to each other at one point. Note that the movement of the neck joint 6a realizes a movement corresponding to the movement of the fingertips of a puppeteer of a Bunraku puppet.

Further, the first link part 22 that supports the neck part 6 has a substantially Z-shape in the XZ plane, and the neck part 6 is arranged so as to be retreated from the chest 8 toward the back side. In this way, by arranging the neck 6 offset to the back side of the chest 8, it is possible to maintain a balanced posture, which is different from that of an actual human being, and create a floating feeling.

The chest 8 includes a chest joint part 8a that supports the first link part 22, and a chest link part 8b that supports the chest joint part 8a. The thoracic joint part 8a is composed of three motors arranged such that their output axes are orthogonal to each other at one point, and can rotate around a roll axis, a pitch axis, and a yaw axis. Further, the chest link portion 8b can expand and contract in the Z-axis direction. Therefore, the chest 8 has four degrees of freedom: rotation around the roll axis, around the pitch axis, around the yaw axis, and expansion and contraction in the Z-axis direction. Here, the expansion and contraction of the chest link part 8b is also realized by a known technique in the same way as the neck link part 6b. The movement of the thoracic joint 8a corresponds to the movement of the wrist of a bunraku puppeteer.

FIG. 2 is a diagram showing a state in which the neck link part 6b and the chest link part 8b are extended in the Z-axis direction in the motion expression mechanism 2. In this way, the movement of the head 4 and the chest 8 to expand and contract cannot occur in actual human movements, but when the motion expression mechanism 2 is used in a humanoid robot, it is possible to express human movements through such expansion and contraction. Can be deformed.

In addition, by moving the neck and torso up and down and expanding and contracting, the robot is able to convey the state of the conversation not only to the interlocutor but also to the people around it, improving the relationship when communicating between humans and robots. This can increase affinity. Furthermore, by making it easier for people to understand the robot's emotional expressions, it can compensate for the robot's tendency to be clumsy.

The arm portions 10 each have a substantially U-shape and include a base portion 10a, an inner shoulder portion 10b, an outer shoulder portion 10c, an elbow portion 10d, and a wrist portion 10e as joint portions. Moreover, each joint part is connected by a link member. Here, the base portion 10a is connected to a second link portion 24 located between the chest portion 8 and the waist portion 12. The base portion 10a can rotate around the roll axis and around the pitch axis, and has two degrees of freedom. Note that the inner shoulder portion 10b, the outer shoulder portion 10c, and the wrist portion 10e are each formed only from joint portions that rotate only around the roll axis, and have one degree of freedom. Further, the elbow portion 10d can rotate around a roll axis, a pitch axis, and a yaw axis, and has three degrees of freedom. That is, each arm portion 10 has a total of eight degrees of freedom in one arm.

As described above, by connecting the arm 10 to the second link 24 located between the chest 8 and the waist 12, the arm 10 is connected to the second link 24 located between the chest 8 and the waist 12. Since the arm portion 10 is not connected to the upper body portion, it is possible to reduce the mass of the trunk and lower the height of the center of gravity. Therefore, in addition to significantly reducing the amount of inertia applied to the actuators of the chest 8 and waist 12, a larger, high-output, high-response motor can be used in the arm 10. Therefore, it is possible to vibrate the upper body and the arm 10 at a faster frequency, and it is possible to reproduce minute movements such as when crying, for example, in a more exaggerated manner than in reality.

The waist part 12 is formed only from a joint part that supports the second link part 24, and consists of three motors arranged so that their output shafts are orthogonal to each other at one point. Therefore, the waist portion 12 can rotate around the roll axis, the pitch axis, and the yaw axis, and has three degrees of freedom. The motion expression mechanism 2 has three degree-of-freedom components in the trunk (neck 6, chest 8, and waist 12) that have joints with three degrees of freedom around the pitch axis, roll axis, and yaw axis. We are prepared. For this reason, for example, as shown in FIG. 3, when the motion expression mechanism 2 is used for the skeleton of a female robot, the neck 6, the chest 8, and the waist 12 are refracted to improve the posture seen from the front. It is possible to reproduce subtle proportions that appeal to femininity, such as drawing an S-shape. Further, as shown in FIG. 4, delicate proportions can be reproduced by bending the neck 6, chest 8, and waist 12 even when viewed from the side. The movement of the waist 12 corresponds to the movement of the elbows of a Bunraku puppeteer.

The knee portion 14 is formed only from a joint portion that supports the third link portion 26. This knee portion 14 is composed of one motor that rotates around the pitch axis and has one degree of freedom.
The foot portion 16 is formed only from a joint portion that supports the fourth link portion 28. This foot portion 16 is composed of two motors that rotate around a roll axis and a pitch axis, and has two degrees of freedom. Further, the foot portion 16 is fixed onto a flat foot surface portion 18. The motion expression mechanism 2 is placed on the XY plane by the foot surface portion 18 so as not to fall over, and can take an extreme posture without falling over, thereby attracting viewers.

According to the motion expression mechanism 2 according to this embodiment, the degrees of freedom include joints with three degrees of freedom around the pitch axis, around the roll axis, and around the yaw axis at three locations: the neck 6, the chest 8, and the waist 12. By providing these components, it is possible to reproduce rich emotional expressions through exaggerated movements that are not found in real humans, as well as delicate human proportions.

Furthermore, as shown in FIG. 5, the movement of the motion expression mechanism 2 causes the neck 6, the chest 8, and the waist 12 to meander in a figure-8-shaped trajectory centering on the chest 8, and also causes the shoulder 27 joints to meander. He can bend the joints of his elbows and elbows. Therefore, complex movements such as dance can be reproduced relatively faithfully.

Furthermore, by arranging the neck 6 offset to the back side of the chest 8, a beautiful S-shaped curve can be exaggerated with respect to the central axis of the trunk. Furthermore, as shown in FIG. 4, a beautiful curve can be maintained even when the neck 6 is tilted forward and the nape line is aligned.

Further, by adding a degree of freedom to the head 4 and the chest 8 to expand and contract in the Z-axis direction, which is not possible in actual human motion, human motion can be deformed.
In addition, in the degree of freedom configuration section, by configuring the joint section by arranging the motors so that the output axes are orthogonal to each other at one point, it is possible to express motion without any discomfort. In particular, by making the roll axis and the pitch axis of the waist portion 12 into one joint, the sense of discomfort can be eliminated. Furthermore, by adding a yaw axis to the joints, the abdomen above the waist 12 rotates, making it possible to achieve a feminine image.

In addition, in the above-mentioned embodiment, as shown in FIG. 6, a translation part 30 may be provided in the vicinity of the neck part 6, which constitutes a degree of freedom to translate in the X-axis direction and the Y-axis direction. This translation part 30 further connects an L-shaped link 30a to the rear of the first link part 22, arranges a roll part 30b that rotates around a roll axis on it, and furthermore has horizontal link parts on both sides in the Y-axis direction. 30c is extended, and cross portions 30d are arranged in the X-axis direction and the Y-axis direction at the tips of both horizontal link portions 30c. The cross portion 30d includes a first elastic portion 30y that expands and contracts in the Y-axis direction and a second elastic portion 30x that expands and contracts in the X-axis direction. The second stretchable section 30x is fixed to the first stretchable section 30y, and changes its position in the Y-axis direction as the first stretchable section 30y expands and contracts, like an XY plotter. Of course, the first stretchable section 30y may be fixed to the second stretchable section 30x, and the position in the X-axis direction may be changed as the second stretchable section 30x expands and contracts. This enables delicate expression by minutely changing the relative position of the neck 6 with respect to the plane connecting both shoulders (30d, 30d). Note that the operation of the translation unit 30 is particularly effective when a flexible costume is used as an exterior.

Furthermore, in the above-described embodiment, the degree-of-freedom component having three degrees of freedom joints around the pitch axis, around the roll axis, and around the yaw axis is provided in areas other than the neck 6, the chest 8, and the waist. Good too. That is, four or more degree-of-freedom constituent parts having joint parts with three degrees of freedom may be provided. In this case, richer emotional expression can be realized.

Further, in the above-described embodiment, the motion expression mechanism 2 is explained using a humanoid mechanism as an example, but the motion expression mechanism 2 is not necessarily limited to a humanoid mechanism. For example, it can be applied to living things such as animals as well as inanimate objects such as microwave ovens, televisions, and chairs.

Further, in the above-described embodiment, the arm portion of the person (reference numeral 20 in FIGS. 3 and 4) may be made to expand and contract. This allows for even richer emotional expression.
Further, in the above-described embodiment, the joint is formed by a motor, but a ball joint such as a ball joint may be used instead of the motor. This makes it possible to achieve delicate and flexible movements that are closer to those of a real human, rather than robot-like movements. In addition, since multiple degrees of freedom can be realized at the same height in the degree-of-freedom configuration section, it is possible to express motions that are more natural. Further, when a motor is used in the shoulders and elbows, the joints become enlarged, but by using a ball and socket joint, such enlargement of the joints can be prevented. Note that it is preferable that the movement of the motion expression mechanism 2 by moving the degrees of freedom component can be controlled remotely.

In addition, in the above-described embodiment, the neck 6 is arranged offset to the back side from the chest 8, but as shown in FIG. 7, the neck 6 is arranged offset from the chest 8 to the front side. You can. If the motion expression mechanism 2 is not a humanoid mechanism but an animal, this may allow emotional expressions closer to the real thing. Note that, of course, the neck portion 6 may be placed directly above the chest 8 without shifting the position of the neck portion 6 in the X-axis direction.

Further, in the above-described embodiment, as shown in FIG. 8, a slide mechanism 22a for sliding the neck portion 6 back and forth (in the X-axis direction) may be provided in the first link portion 22. By being able to move the head back and forth in this way, it is possible to realistically create the atmosphere of a conversation. In addition, by allowing the head to move forward and backward, it is possible to realistically achieve not only an S-shaped proportion but also the functional beauty of a human being.

2 Motion expression mechanism 4 Head 6 Neck 6a Neck joint 6b Neck link 8 Chest 8a Thoracic joint 8b Chest link 10 Arm 10a Base 10b Inner shoulder 10c Outer shoulder 10d Elbow 10e Wrist 12 Waist 14 Knee Section 16 Foot section 18 Foot section 20 Arm 22 First link section 22a Slide mechanism 24 Second link section 26 Third link section 27 Shoulder 28 Fourth link section 29 Elbow 30 Translation section 30a L-shaped link 30b Roll section 30c Horizontal link section 30d Cross section 30x Second elastic section 30y First elastic section

Claims (5)

A motion expression mechanism used for a motion body having multiple joints,
placed on the neck, chest, and waist of the operating body,Degree-of-freedom component having at least three degrees of freedom around the pitch axis, around the roll axis, and around the yaw axisand,
a link portion located between the chest and the waist;
an arm connected to the link;
An action expression mechanism characterized by comprising:. 2. The motion expression mechanism according to claim 1 , wherein the neck portion is disposed to be shifted toward the front side or the back side with respect to the chest portion. 3. The motion expression mechanism according to claim 1 , wherein the chest includes a chest link part that expands and contracts in the vertical direction. The motion expression mechanism according to any one of claims 1 to 3 , wherein the neck portion includes a neck link portion that expands and contracts in the vertical direction. The motion expression mechanism according to any one of claims 1 to 4, further comprising a slide mechanism that slides the neck back and forth.

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