JP2003071754A - Robot apparatus and control method thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To propose a robot device and a control method thereof that enable smooth and reliable expression of motion. A first link is connected to the body via a first joint mechanism, and a second link is connected to the first link via a second joint mechanism. A robot apparatus in which a mechanism is provided with first drive means for rotating and driving a first link, and a second joint mechanism is provided with a second drive means for rotating and driving a second link.
By controlling the first driving means, the first link is positioned at a predetermined rotation position where the second link can contact the operation reference plane on which the body is placed with a smaller inclination than the vertical, and then the first link And controlling the second driving means to generate torque in the first driving means so as to fix the first link to the body portion, and to press the operation reference plane by the second link. The second link was driven to rotate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot apparatus and its control method, and is suitable for application to, for example, a pet robot.

[0002]

2. Description of the Related Art In recent years, a four-legged walking type pet robot has been developed and sold by the present applicant. Such a pet robot has a shape similar to dogs and cats raised in ordinary households, and is designed to be able to autonomously act according to the user's actions such as “striking” and “stroking” and the surrounding environment. It was done by.

[0003]

By the way, in such a pet robot, for example, as shown in FIG. 9 (A), the body portion 51 is raised from the forward tilted posture in which both rear leg portions 50 are extended in the forward direction (arrow a). As for the movement, only the corresponding actuator in the hip joint 52 of the rear leg portion 50 is driven to move the body portion 5
This has been done by rotating the body portion 51 in the rearward direction (the direction opposite to the arrow a) in a state in which the hip corresponding portion 1 is grounded.

In this case, the body portion 5 is formed by such a method.
In order to raise 1, the length from the hip joint 52 to the knee joint 53 is L ₁ , the length from the knee joint 53 to the ground contact portion in the rear leg portion 50 is L ₂ , and the rear leg when raising the body portion 51 The force of the ground contact portion of the portion 50 acting on the ground 54 is F, and the moments of the hip joint 52 and the knee joint 53 are M ₁ and M, respectively.
₁ ', where m is the torque required to raise the body 51, the following equation

[0005]

[Equation 1]

Since the above equation holds, the maximum output torque of the actuator is defined as T, and this maximum output torque is expressed by the following equation.

[0007]

[Equation 2]

It is understood that it is sufficient to satisfy the condition.

However, according to such a conventional method, the load applied to the actuator is excessive, and the body portion 51 can be smoothly and surely raised depending on the ground condition (inclination, unevenness, etc.) and the performance of the actuator. There was a risk of disappearing.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a robot apparatus and a control method thereof that enable smooth and reliable expression of motion.

[0011]

In order to solve the above problems, according to the present invention, the first link is connected to the body through the first joint mechanism, and the second link is connected to the first link.
In a robot apparatus in which a second link is connected via the joint mechanism of (1), first driving means for rotationally driving the first link, second driving means for rotationally driving the second link, and And a control means for controlling the second drive means, the control means controls the first drive means so that the first link and the second link serve as an operation reference plane on which the body portion is placed. After being positioned at a predetermined rotational position where the contact can be made with an inclination smaller than vertical, the first and second driving means are controlled to fix the first link to the body portion.
The second link is rotationally driven so as to push the operation reference plane by the second link while generating torque in the driving means.

As a result, in this robot apparatus, the body part can be lifted by the force of the second link pressing the motion reference plane. In this case, the distance from the first axis in the first joint mechanism to the contact portion of the second link with the operation reference plane, and the operation in the second link from the second axis in the second joint mechanism. The latter is smaller in terms of the distance to the contact area with the reference surface. Therefore, the second drive means can lift the body portion with a smaller torque than the case of the first drive means, and the lift can be performed more smoothly and surely.

According to the present invention, the first link is connected to the body through the first joint mechanism, and
The second link mechanism is connected to the second link mechanism via the second link mechanism, the first link mechanism is provided with the first drive means for rotationally driving the first link, and the second link mechanism is linked to the second link mechanism. In a method for controlling a robot apparatus provided with a second drive means for rotationally driving the second link, the first drive means is controlled to place the first link and the second link on the body portion. A first step of arranging the first and second driving means at a predetermined rotational position where the contact can be made with an inclination smaller than vertical with respect to the operation reference plane, and a first step with respect to the body section is performed.
And a second step of rotationally driving the second link so as to push the operation reference surface by the second link while generating torque in the first driving unit so as to fix the link.

As a result, according to this control method for the robot apparatus, the body portion of the robot apparatus can be lifted by the force of the second link pushing the motion reference plane. In this case, the distance from the first axis in the first joint mechanism to the contact portion of the second link with the operation reference plane, and the operation in the second link from the second axis in the second joint mechanism. The latter is smaller in terms of the distance to the contact area with the reference surface. Therefore, the second drive means can lift the body portion with a smaller torque than the case of the first drive means, and the lift can be performed more smoothly and surely.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

(1) Structure of Pet Robot According to this Embodiment In FIG. 1, reference numeral 1 denotes the pet robot according to this embodiment as a whole, and leg units 3A to 3D are connected to the front, rear, left and right of the body unit 2, respectively. In addition, the head unit 5 is connected to the front end of the body unit 2 with the collar 4 interposed therebetween.

In this case, in the body unit 2, as shown in FIG. 2, a controller 10 for controlling the operation of the entire pet robot 1, a battery 11 serving as a power source of the pet robot 1, a battery sensor 12 and Various internal sensors such as the temperature sensor 13 and the like, a speaker 14 that functions as a substantial “mouth” of the pet robot 1, a detachable external memory 15 in which various control parameters are stored, and the like are stored. In addition, near the rear end of the upper surface of the body unit 2, an LED (Light Emitting D
An external tail portion 17 made of a joystick in which the iode 16 is housed is provided so as to project.

Further, the head unit 5 has a CCD (Charge Coupl) corresponding to the substantial "eyes" of the pet robot.
ed Device) A camera 18 and a microphone 19 corresponding to a substantial “ear” are housed, and a corner portion 21 (FIG. 1) of a predetermined shape which houses an LED 20 is provided on the top of the head so as to project. There is.

Further, the thighs of the leg units 3A to 3D
22 and each knee joint 24 connecting the shin 23,
Each of the leg units 3A to 3D and the body unit 2 respectively
The hip joints 25 to be connected together, the head unit 5 and the torso
Each of the neck joints 26 and the like connecting the body unit 2 has
Actuator 27 with a corresponding number of degrees of freedom₁~ 27 _n
And potentiometer 28₁~ 28_nIs installed
It

The CCD camera 18 of the head unit 5
Captures the surrounding situation and sends the obtained image signal S1 to the controller 10. In addition, the microphone 19 collects voice commands such as “walk”, “sitting” or “follow the ball” and ambient sounds emitted by the user, and sends the voice signal S2 thus obtained to the controller 10.

Further, the battery sensor 1 of the body unit 2
2 detects the remaining amount of the battery 11, sends the detection result to the controller 10 as a battery remaining amount detection signal S3, and the temperature sensor 13 detects the internal temperature of the body unit 2 and outputs the detection result to the temperature. The detection signal S4 is sent to the controller 10.

Further, each potentiometer 28₁~ 28_n
Is the corresponding actuator 27₁~ 27_nOf the output shaft of
The rotation angle is detected, and the detection result is the angle detection signal S5.₁~
S5 _nTo the controller 10 as a body unit
The tail portion 17 of the gland 2 responds to this when the user operates it.
The same operation detection signal S6 is sent to the controller 10.

The controller 10 includes a CCD camera 18,
Microphone 19, battery sensor 12, temperature sensor 1
3. Potentiometers 28 _{1 to} 28 _n and tail portion 17
Based on the image signal S1, the audio signal S2, the battery remaining amount detection signal S3, the temperature detection signal S4, the angle detection signals S5 _{1 to} S5 _{n, the} operation detection signal S6, etc. given from Determines whether there is a command from the user and whether there is an action from the user.

Then, the controller 10 determines the subsequent action based on the result of this determination, the control program stored in advance in the internal memory 10A, and various control parameters stored in the external memory 15, and the necessary action is determined based on the determination result. By vibrating the different actuators 27 _{1 to} 27 _n , the pet robot 1 is caused to perform actions such as swinging the head unit 5 vertically and horizontally and driving the leg units 3A to 3D to walk.

Further, at this time, the controller 10 outputs a voice based on the voice signal S7 to the outside by giving a predetermined voice signal S7 to the speaker 14 as needed, or in the corner portion 21 and the tail portion 17. The LEDs 20, 16 are turned on, turned off, or blinked.

In this way, the pet robot 10 behaves autonomously according to the external and internal conditions, the presence / absence of commands and actions from the user, various control parameters stored in the external memory 15, and the like. It is designed to get you.

(2) Processing of Controller 10 Here, the processing of the controller 10 relating to such action generation of the pet robot 1 will be described.

As shown in FIG. 3, when the processing contents of the controller 10 relating to the action generation of the pet robot 1 are functionally classified, the state recognition unit 30 that recognizes the external and internal states and the recognition result of the state recognition unit 30. An emotion / instinct model 31 that determines an emotion and an instinct state based on the action, and an action that determines the next action based on the recognition result of the state recognition unit 30 and the emotion / instinct state determined in the emotion / instinct model 31 Based on the determination unit 32, a posture transition control unit 33 that makes a series of motion plans of the pet robot 1 for performing the action or action decided by the action determination unit 32, and the action plan made by the posture transition control unit 33 LED16,
20 and the actuators 27 _{1 to} 27 _{n and} other device control units 34 that control devices.

In this case, the state recognition section 30 includes an image signal S1 and a voice signal S2 provided from the CCD camera 18, the microphone 19, the battery sensor 12, the temperature sensor 13, the potentiometers 28 _{1 to} 28 _{n, the} tail section 17, and the like.
Battery level detection signal S3, the temperature detection signal S4, recognizes a particular state based on the various sensor signal S10 such as the angle detection signal S5 _{1-S5 n} and the operation detection signal S6, the recognition result as the state recognition information D1 Emotional / instinct model 31
Also, the action determination unit 32 is notified.

Specifically, the state recognizing section 30 constantly monitors the image signal S1 given from the CCD camera 18, and in the image based on the image signal S1, for example, "a red round object" or "an object located in the traveling direction". When it detects "," it recognizes that "there is a ball" and "there is an obstacle", and notifies the emotion / instinct model 31 and the action determination unit 32 of the recognition result.

The state recognition unit 30 also includes a microphone 19
The audio signal S2 given by the HMM (Hi
When various voices such as “walk”, “prone”, “follow the ball” are recognized by a voice recognition method such as the dden Markov Model) method, the voice is notified to the emotion / instinct model 31 and the action determination unit 32.

Further, the state recognition unit 30 recognizes the remaining amount of the battery and the internal temperature based on the battery remaining amount detection signal S3 and the temperature detection signal S4 provided from the battery sensor 12 and the temperature sensor 14, respectively, and the recognition result is emotional.・
The instinct model 31 and the action determination unit 32 are notified.

Further, the state recognizing section detects the angle detection signals S5 _{1 to} S 5 given by the potentiometers 28 _{1 to} 28 _n.
5 _n is constantly monitored and, for example, angle detection signals S5 _{1 to} S5 from potentiometers 28 _{1 to} 28 _n corresponding to the actuators 27 _{1 to} 27 _n in the pitch direction of the head unit 5, for example.
When it is detected that the head unit 5 is pushed downward or upward based on _n , it is recognized as "praised" or "scold", and the recognition result is the emotion / instinct model 31 and action determination. Notify the section 32.

Furthermore, the state recognition section 30 constantly monitors the operation detection signal S6 given from the tail section 17, and when it detects that the tail section 17 has been operated based on the operation detection signal S6, it responds to the operation. The intention of the user is recognized, and the recognition result is notified to the emotion / instinct model 31 and the action determination unit 32.

The emotion / instinctive model section 31 is "joyful",
With respect to a total of six emotions of “sadness”, “surprise”, “fear”, “disgust”, and “anger”, a parameter representing the intensity of the emotion is held for each emotion. The emotion / instinct model unit 31 then sets the parameter values of each of these emotions based on specific recognition results such as “praised” and “scold” given as the state recognition information D1 from the state recognition unit 30. Change sequentially.

Similarly, the emotion / instinct model unit 31 has five independent desires of "love desire", "search desire", "exercise desire", "charge desire" and "sleep desire". , Each of these desires holds a parameter indicating the strength of the desire. And the emotion / instinct model part 31
The parameter value of each of these desires is set to the state recognition unit 3 respectively.
It is sequentially changed based on the recognition result from 0, the elapsed time, and the like.

On the other hand, the action deciding section 32 includes the state recognizing section 30.
When the state recognition information D1 is given by the user, when a certain time has passed after the current action, or when the emotion or instinct model 31 has any emotion or instinct parameter value exceeding a threshold value, The next action is determined based on the control program stored in the internal memory 10A and the control parameters stored in the external memory 15.

Specifically, the action determining section 32 determines the state as a node N as shown in FIG. 4 as a method for determining the next action.
Expressed as D _{A0 to} ND _An , one node ND _A0
Then which nodes or transitions to _ND A0 _{~ND An,} connecting between its own node _ND A0 _{to ND} completed in _{A n} or each node _ND A0 _{to ND An} from the arc _{AR A0}
~ Transition Probability P ₀ Set for AR _An ~
An algorithm called a probabilistic automaton that determines probabilistically based on P _n is used.

In this case, the connection relation between the nodes ND _{A0 to} ND _An and the arcs A in this probability automaton.
R _A0 to Ar transition probability _P 1 to P _n and for _An, the external memory 1 as the arc _AR A0 _{to Ar An} action associated respectively control parameters (action model)
Stored in 5.

Then, the action determining section 32, for example, recognizes the state.
When the state recognition information D1 is given from the section 30,
Node (ND_A0) Has passed a certain time
When, any emotion in the emotion / instinct model part 31
Or when the instinct's parameter value exceeds the threshold,
The next transition destination node (N
D_A0~ ND_An) Each arc AR_A0~ AR_AnAgainst
Transition probability P₀~ P _nProbabilistically based on
Node (ND_A0~ ND_An) And the original
Mode (ND_A0) Is connected to the arc (AR_A0~ AR
_An) As the action to be expressed next
And notifies the posture transition control unit 33 as the action determination information D2
To do.

In the posture transition control unit 33, when the action decision information D2 is given from the action decision unit 32, a series of action plans of the pet robot 1 for taking an action based on the action decision information D2 are made, and the action is concerned. The operation command information D3 based on the plan is output to the device control unit 34.

In this case, the posture transition control section 33 determines the postures of the pet robot 1 as shown in FIG.
_{B0 to} ND _B2, and transitionable nodes ND _{B0 to} ND
Conclusion In a directed arc _AR B0 _{to Ar B5} representing the operation between _B2, and the operation to complete on one node _ND B0 _{to ND B2} using a directed graph to represent as a self-operating arc _AR C0 _{~AR C3.}

Specifically, in the case of the pet robot 1, each node ND _{B0 to} ND _B2 is associated with a posture such as “standing”, “sitting”, “down”, and the like.
The directed arcs AR _{B0 to} AR _B5 that connect the nodes ND _{B0 to} ND _B2 , respectively, are associated with the movement for changing the posture. Also, each self-moving arc A
R _{C 0 to A} RC ₃ are associated with various actions such as “walking”, “dancing”, “shaking the head”, and “handing” that can be expressed in the corresponding postures.

Then, the posture transition control unit 33 receives the action command such as "stand", "walk", "dance" from the action determining unit 32 as the action determining information D2, and then the directed arcs AR _{B0 to} AR _B2. while following the orientation node is designated attitude or operation associated with the current node _ND B0 _{~ND B2 ND} B0 _{~ND B2} or directed arc _AR B0 _{to Ar B5} or self operating arc _{AR C0} ~
The shortest route to AR _C3 is searched, and each directed arc AR _{B0 to} AR _B5 and the self-moving arc A on the searched route are searched.
The operation commands for sequentially performing the operations respectively associated with R _{C0 to} AR _C3 are sequentially output to the device control unit 34 as the operation command information D3.

For example, when the pet robot 1 is in the "down" posture, the posture control control unit 33 "falls down" when the action determining unit 32 gives an action command of "sitting and banzai". ND _B2 corresponding to the posture of “sit” and node ND _B1 corresponding to the posture of “sitting”
"Sit" associated with the directed arc AR _B1 that connects the two
And a motion command of a motion called "Banzai" (hereinafter, referred to as "Banzai motion") associated with the self-motion arc AR _C1. Will be sequentially transmitted to the device control unit 34.

In the device control unit 34, each directed arc AR of the directed graph held by the posture transition control unit 33.
_{B0 to} AR _B5 and each self-moving arc AR _{C0 to} AR _C3
Each of the actions, such as which actuator 27 _{1 to} 27 _n (FIG. 2) is driven at which timing and in order to cause the pet robot 1 to express the action in association with each action respectively associated with the action. A file that defines the time-series control contents of the actuators 27 _{1 to} 27 _n (hereinafter, referred to as operation file)
In the external memory 15.

[0047] The device control unit 34, each time the given operation command information D3 from the posture transition control unit 33, are sequentially reproduced corresponding operation file based on the control parameters stored in the operation file drive signals S11 ₁ ~
S11 generates _n, by a corresponding actuator ₂₇ 1 ~ 27 _n for controlling the driving based on the driving signal _S11 1 ～S11 _n, expressing an operation corresponding to the pet robot 1.

Therefore, the device control section 34, for example, when the pet robot 1 is in the "down" posture,
When the above-mentioned “sit motion” and “banzai motion” motion commands are sequentially given from the posture transition control unit 33, first, the corresponding actuators 27 _{1 to} 27 _n based on the motion file corresponding to the “sitting motion”. The "sit motion" is expressed in the pet robot 1 by sequentially controlling the time series, and thereafter, the corresponding actuators 27 ₁ based on the motion file corresponding to the "Banzai motion".
The "banzai motion" is caused to appear in the pet robot 1 by sequentially controlling ~ 27 _n in time series. As a result, the pet robot 1 as a whole exhibits a series of motions in which the posture is changed from “down” to “sitting” and then “banzai”.

Further, the device control unit 34 controls the WA of various sounds.
Multiple audio files that are VE files and LED1
A plurality of LEs in which drive data of 6 and 20 (FIG. 2) are stored
The pet drive 1 has a D drive file in the external memory 15, and when the motion file is played back, the voice file and / or the LED drive file associated with the motion file are played back at the same time, thereby causing the pet robot 1 to move. In addition, output audio from the speaker 14 (Fig. 2),
The LEDs 16 and 20 are driven to blink.

In this way, the controller 10 can make the pet robot 1 act autonomously according to the external and internal conditions, the command from the user and the presence or absence of the action.

(3) Sitting Motion in Pet Robot 1 Next, a specific motion of the above-mentioned “sitting motion” in the pet robot 1 will be described. In the pet robot 1, each hip joint 25 (FIG. 1) has a pitch direction (a rotation direction around an axis parallel to the arrow y in FIG. 1) and a roll direction (centered around an axis parallel to the arrow x in FIG. 1). Each knee joint 24 has two degrees of freedom
(FIG. 1) has one degree of freedom in the pitch direction.

In the case of this pet robot 1, "fall down"
Then, as shown in FIG. 6 (A), while the abdomen of the body unit 2 is grounded on the ground 40, the front, rear, left and right leg units 3A to 3D are respectively extended in the forward direction indicated by the arrow x. .

Then, in the same manner as in the case of "pushing up" from this state, the pet robot 1 has left and right front leg units (hereinafter, referred to as front leg units) 3A,
By bending and extending 3B, as shown in FIG. 6 (B), while the curved surface portion 2B of the hip corresponding to the rear end of the abdomen of the body unit 2 is grounded on the ground 40, both legs on the rear side are grounded. Unit (hereinafter these are referred to as rear leg units) 3
Extend C and 3D forward, and each front leg unit 3
The postures of the tip portions of the shins 23 of A and 3B are changed to a posture in which the tip portions are grounded.

Next, the pet robot 1 uses the actuators 27 ₁ to 27 ₁ of the knee joint 24 of each of the rear leg units 3C and 3D.
27 _n and the actuators 27 _{1 to} 27 _{n in} the pitch direction of hip joints (hereinafter, these are referred to as rear hip joints) 25 that respectively connect the rear leg units 3C and 3D to the body unit 2 respectively. As a result, as shown in FIG. 7 (A), the thighs 22 of the respective rear leg units 3C and 3D, and the shins 23 of these rear leg units 3C and 3D have a predetermined size smaller than perpendicular to the ground 40. It takes a posture in which it is positioned at a predetermined rotational position where it comes into contact with an inclination.

After that, the pet robot 1 then attaches to the body unit 2 the thighs 2 of the rear leg units 3C and 3D.
2 so as to fix (ie, each rear leg unit 3
While controlling the torques generated in the pitch direction actuators 27 _{1 to} 27 _n of the rear hip joint 25 so that the C and 3D thighs 22 do not rotate in the pitch direction relative to the body unit 2, respectively. , Each rear leg unit 3
Actuators 27 _{1 to} 27 _{n of the} C and 3D knee joint 24
By driving the knee joint 24 by bending, the shins 23 of the rear leg units 3C and 3D are respectively moved to the ground 40.
Rotate to press.

As a result, as the shins 23 of the rear leg units 3C and 3D rotate, the angles formed by the shins 23 and the ground 24 become closer to vertical, and accordingly, the shins 23 cause the rear legs to move. The knee joints 24 of the unit units 3C and 3D are pushed in the longitudinal direction of the shin 23. At this time, since the thighs 22 of the rear leg units 3C and 3D are fixed so as not to rotate in the pitch direction relative to the body unit 2 as described above, the body unit 2 Rotates around the ground contact portion of the curved surface portion 2B corresponding to the hip in a backward direction (direction opposite to the arrow x).

When the pet robot 1 finishes bending the knee joint 24 of each of the rear leg units 3C and 3D to a predetermined angle in this way, the knee joint of each of the rear leg units 3C and 3D is subsequently continued. While driving the actuators 27 _{1 to} 27 _n in the pitch direction of 24 to extend the knee joints 24 so that the shins 23 of the rear leg units 3C and 3D slide forward on the ground 40, The actuators 27 _{1 to} 27 _n in the pitch direction of the rear hip joint 25 are driven to rotate the body unit 2 in the raising direction (backward direction).

As a result, the body unit 2 becomes
While B is grounded, it gradually rises while rotating backward so as to fall down, and eventually this series of standing-up motions is completed with the flat surface portion (not shown) provided at the buttocks of the body unit 2 grounded. It becomes a "sit" posture as shown in FIG.

Here, in such a series of sitting motions of the pet robot 1, the torque required for the actuators 27 _{1 to} 27 _n in the pitch direction of each rear hip joint 25 and the knee joints of each rear leg unit 3C, 3D. Actuator 27
Consider the torque required to ₁ ~27 _n.

For example, from the state of FIG. 6 (B), the actuator 27 _{1 in} the pitch direction of the rear hip joint 25 as in the conventional case.
In the case of raising the torso unit 2 by using only ~ 27 _n , when the actuators 27 _{1 to} 27 _n generate the torque m required to raise the torso unit 2, the rear leg units 3C and 3D. The force F that pushes the ground at the ground contact area is calculated by the following equation with reference to FIG.

[0061]

[Equation 3]

Can be represented by

On the other hand, the pet according to the present embodiment
Like the robot 1, this force F is applied to the body unit 2
The position of the thigh 22 of the rear leg unit 3C, 3D
Fix and fix the knee joint 24 of the rear leg unit 3C, 3D.
Actuator 27₁~ 27 _nWhen generated by
Moment M of the knee joint 24_TwoRefer to Fig. 9 (A)
Approximately,

[0064]

[Equation 4]

It is represented by

In this case,

[0067]

[Equation 5]

Since the following holds, the equations (1) and (4)
From comparison of the formula, (in the case of (1) _{(L 1 + L 2),} (4) L 2 in the case of formula) the distance from the power point to the action point amount that is shortened, the actuator 27 of the knee joint 24 _1-27
It can be seen that the torque M ₂ ′ that _n should generate is smaller than that when the body unit 2 is raised by the torque M ₁ generated by the actuators 27 _{1 to} 27 _{n in} the pitch direction of the rear hip joint 25.

In practice, for example, when L1 and L2 are substantially equal, the actuators 27 _{1 to} 27 _n of the knee joint 24 are
The torque M ₂ ′ that should be generated is about half that when the body unit 2 is raised by the torque M ₁ generated by the actuators 27 _{1 to} 27 _{n in} the pitch direction of the rear hip joint 25.

On the other hand, at this time, the actuators 27 _{1 to} 27 _{n in} the pitch direction of the rear hip joint 25 support the torso unit 2 (the thighs 22 of the rear leg units 3C and 3D are fixed to the torso unit 2). ) Required torque M ₂
Is the expression

[0071]

[Equation 6]

It becomes

Therefore, the following equation

[0074]

[Equation 7]

If the following relationship is established, the body unit 2
Does not lose the torque T ′ that tends to fall in the front direction due to its own weight, and the torque M ₂ generated by the actuators 27 _{1 to} 27 _{n in} the pitch direction of the rear hip joint 25 causes the thigh portion 22 of the rear leg units 3C and 3D. Torso unit 2
It can be seen that the body unit 2 can be raised by the torque M ₂ ′ generated by the actuators 27 _{1 to} 27 _n of the knee joint 24 of the rear leg units 3C and 3D while being fixed to.

Here, this torque M_TwoAnd the expression (1)
Luk M₁Considering the relationship with the
Actuator 27₁~ 27_nMaximum torque of
To T ₀, The actuator 27₁~ 27_nProvided in
The reduction ratio of the reduction mechanism is Z, and the transmission efficiency of this reduction mechanism is η
Then, the maximum output torque output through the reduction mechanism
T is the following formula

[0077]

[Equation 8]

The reverse rotation torque (T 'in the equation (7)) required to overcome the maximum torque of the actuators 27 _{1 to} 27 _n from the output side of the reduction mechanism to reversely rotate is
The following formula

[0079]

[Equation 9]

The transmission efficiency η is

[0081]

[Equation 10]

To satisfy the following equation,

[0083]

[Equation 11]

The following relationship is established.

Therefore, as is apparent from the equations (11), (2) and (7), the actuators 27 ₁ to 27 _{1 in} the pitch direction of the rear hip joint 25 in the present embodiment.
Since the torque M ₂ required for 7 _n is a value smaller than the torque M ₁ required in the conventional operation method, when the same actuators 27 _{1 to} 27 _n as the conventional actuators are used. Also, such a series of operations can be performed smoothly and reliably.

Further, when the rear hip joints 25 and the knee joints 24 of the rear leg units 3C and 3D are driven from the state shown in FIG. 7B to the state shown in FIG. With reference to (B) and (B), the force point that is the rotation center P ₁ of the rear leg unit in the rear hip joint 25 and the rear leg unit in the rear hip joint 25 by the amount of bending of the knee joint portion 24 of each rear leg unit 3C, 3D. The distance 1 from the point of action of the tip of the shin 23 in 3C and 3D, which is the ground contact portion P ₂ , is the distance (L ₁ + when the rear leg units 3C and 3D are extended as shown in FIG. 9A).
Shorter than L ₂ ).

Therefore, in the pet robot 1, the actuators 27 ₁ to 27 ₁ in the pitch direction at the rear hip joint 25 when the body unit 2 is raised by that amount.
Since the load moment of 27 _n is small and the torque required accordingly is smaller than that of the conventional case (FIG. 9 (A)), when the same actuators 27 _{1 to} 27 _n as the conventional one are used. Also in FIG. 7, the operation after FIG. 7B can be smoothly and surely performed.

Furthermore, in this pet robot 1, as shown in FIG.
After (B), the knee joint 24 of each rear leg unit 3C, 3D is replaced by the shin 2 of the rear leg unit 3C, 3D.
Since it operates so as to extend the grounded portion of the body 3 while sliding it on the ground 40, it also assists in raising the body unit 2 as a reaction, and the rear hip joint 25
The load applied to the actuators 27 _{1 to} 27 _n in the pitch direction can be reduced.

(4) Operations and Effects of the Present Embodiment In the pet robot 1 having the above-mentioned configuration, the rear leg units 3C, 3C, from the state of FIG.
While slightly lifting the 3D thigh, the knee joint 24 is bent so that the tip of the shin 23 may come into contact with the ground, and then the thighs 22 of the respective rear leg units 3C and 3D are attached to the body unit 2. While being fixed, the knee joint 24 is bent so as to push the ground 40 by the shin 23 of each of the rear leg units 3C and 3D, thereby shifting to the posture of FIG. 7B.

After this, each rear leg unit 3C, 3
Actuators 27 _{1 to} 27 _n in the pitch direction in the rear hip joint 25 are generated while sliding the ground contact portion of the shin 23 of D on the ground 40 and extending the knee joint 24 of each of the rear leg units 3C and 3D. When the body unit 2 is raised by the torque that is applied, the posture shifts to the "sit" position in FIG.

By such a series of movements, the actuator 27 ₁ in the pitch direction in the rear hip joint 25 ₁
The torque required for ~ 27 _n can be made smaller than that of the conventional _one , and even when an actuator of the same output torque as that of the conventional _{one is} used, 27 _{1 to} 27 _n , it is affected by the condition of the ground surface, etc. This makes it difficult to smoothly and surely perform such sitting motion.

According to the above configuration, the sitting motion of the pet robot 1 is performed by utilizing the bending and extending motions of the rear leg units 3C and 3D as described above.
The actuator 27 in the pitch direction in the rear hip joint 25
_The torque required for _{1 to} 27 _n can be made smaller than in the conventional case, and the sitting motion can be performed smoothly and reliably. In this way, the expression operation of the pet robot 1 can be made natural, and the entertainment property of the pet robot 1 can be improved.

(5) Other Embodiments In the above-described embodiments, the present invention is applied to the body unit 2 via the hip joint 25 as the first joint mechanism and the thigh as the first link. The part 22 is connected, and the thigh 22 is provided with a knee joint 24 as a second joint mechanism.
The case of applying the pet robot 1 configured as shown in FIG. 1 in which the shin 23 as the second link is connected via the above has been described, but the present invention is not limited to this.
The present invention can be widely applied to pet robots having other configurations and various other robot devices other than pet robots.

Further, in the above-described embodiment, FIG.
In the posture of (A), the case has been described in which the shin 23 of each of the rear leg units 3C and 3D is brought into contact with the ground 40 with a predetermined inclination smaller than the vertical, but the present invention is not limited to this. In short, each rear leg unit 3C, 3D
If the thigh portion 22 of each of the rear leg units 3C and 3D is to be positioned at a predetermined rotational position where it can contact the ground 40 (movement reference plane) with an inclination smaller than vertical.
The shin 23 may not be in contact with the ground 40.

[0095]

As described above, according to the present invention, the first link is connected to the body through the first joint mechanism, and the first link is connected through the second joint mechanism. In the robot apparatus in which the two links are connected, a first driving unit that rotationally drives the first link, a second driving unit that rotationally drives the second link, and a first driving unit and a second driving unit. And a control means for controlling the first drive means to contact the first link with the second link at an inclination smaller than perpendicular to the operation reference plane on which the body is placed. After the first and second rotational positions are made possible,
The second link to push the motion reference plane by the second link while controlling the drive means to generate torque in the first drive means so as to fix the first link to the body part. By rotationally driving the robot, it is possible to lift the body portion more smoothly and surely as compared with the case of driving the first driving means, and thus, a robot apparatus that enables smooth and reliable movement expression. realizable.

According to the present invention, the first link is connected to the body part via the first joint mechanism, and the second link is connected to the first link via the second joint mechanism. And a first joint mechanism for rotationally driving the first link.
Drive means is provided, and the second joint mechanism has a second
In a method of controlling a robot apparatus provided with a second drive means for rotationally driving the link, the first drive means is controlled to move the first link and the second link with the body portion placed. A first step of arranging in a predetermined rotational position where the reference surface can be contacted with an inclination smaller than vertical and a first step;
And controlling the second drive means to generate torque in the first drive means so as to fix the first link to the body portion, and to press the operation reference plane by the second link. By providing the second step of rotationally driving the second link, the body portion can be lifted more smoothly and surely as compared with the case of driving the first driving means, and thus smooth and reliable. It is possible to realize a control method of a robot apparatus that enables various motions to be expressed.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an external configuration of a pet robot according to this embodiment.

FIG. 2 is a block diagram showing an internal configuration of a pet robot.

FIG. 3 is a block diagram for explaining processing of a controller.

FIG. 4 is a conceptual diagram for explaining a probability automaton.

FIG. 5 is a conceptual diagram for explaining a directed graph.

FIG. 6 is a side view for explaining a sitting motion of the pet robot.

FIG. 7 is a side view for explaining a sitting motion of the pet robot.

FIG. 8 is a side view for explaining a sitting motion of the pet robot.

FIG. 9 is a schematic diagram for explaining various postures.

[Explanation of symbols]

1 ... Pet robot, 2 ... Body unit, 3A ~
3D ... Leg unit, 10 ... Controller, 22 ...
… Thighs, 23 …… shins, 24 …… knee joints, 25 …… hip joints, 40 …… ground.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C150 CA02 DA05 DA24 DA26 DA27                       DA28 ED42 ED47 ED52 EF07                       EF16 EF22 EF23 EF29 EF33                       EF36                 3C007 AS36 CS08 MT14 WA04 WA14                       WC10 WC22

Claims (2)

[Claims] 1. A robot apparatus in which a first link is connected to a body portion via a first joint mechanism, and a second link is connected to the first link via a second joint mechanism. In the first joint mechanism, there is provided a first drive means for rotationally driving the first link about a predetermined first axis in the first joint mechanism, and the second joint. A second drive means provided in the mechanism and rotationally driving the second link about a predetermined second axis in the second joint mechanism; and controlling the first and second drive means. Control means for controlling the first drive means to control the first link to
After the second link is positioned at a predetermined rotational position where it can contact the movement reference plane on which the body is placed with an inclination smaller than vertical, the first and second driving means are controlled, The first link so as to fix the first link to the body section.
A robot apparatus, wherein the second link is rotationally driven so as to push the operation reference plane by the second link while generating torque in the driving means. 2. A first link is connected to the body part via a first joint mechanism, and a second link is connected to the first link via a second joint mechanism. The first joint mechanism is provided with first drive means for rotationally driving the first link about a predetermined first axis in the first joint mechanism, and the second joint mechanism is The second axis about a predetermined second axis in the second joint mechanism.
In the control method of the robot apparatus, which is provided with the second driving means for rotationally driving the link, the first driving means is controlled so that the first link is
Controlling the first and second driving means, a first step of arranging the second link in a predetermined rotational position where the second link can come into contact with the operation reference plane on which the body portion is placed with an inclination smaller than vertical. The first link so as to fix the first link to the body portion.
And a second step of rotationally driving the second link so as to push the operation reference plane by the second link while generating torque in the driving means. Method.