JP3118775B2 - Robot with link mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot having a link mechanism, and more particularly, to an arrangement of a drive circuit of a motor for driving a joint or a control circuit thereof in an autonomous legged robot.

[0002]

2. Description of the Related Art As an example of an autonomous legged robot, one disclosed in Japanese Patent Application Laid-Open No. 62-97005 has been proposed. Has proposed a legged walking robot.

[0003]

In such a control device for an autonomous robot, the state of the outside world is detected, the state of the outside world is recognized based on the detected amount, the next action is determined, and the movement is performed according to the action plan. It is necessary to perform operations such as speed control or position control of the joint drive motor for the purpose, or force control as necessary, and it is necessary to process a huge amount of information in real time, The computer board on which it is mounted is generally large. Further, since the power supply of the computer and the power supply of the joint drive motor ultimately depend on the mounted battery, it is necessary to mount a battery having a considerable weight and size, depending on the task to be performed. In the prior art, these payloads are stored in the torso, but in the examples known to date, there is no fully autonomous robot yet, and there is a robot with imperfect autonomy. In designing, a part or most of the control device is installed outside the robot, and the robot and the control device are connected by a wire. This implies that it is extremely difficult with the current state of the art to mount all autonomous control devices on the fuselage. Therefore, in designing an autonomous robot, it is important to secure the mounting space for the control device in a limited robot, which becomes increasingly difficult due to the increasing complexity and size of the computer as autonomy increases. It becomes a problem.

Accordingly, a first object of the present invention is to provide a robot having a structure capable of rationally securing a space for mounting the control device in the robot.

[0005] An example in which the entire control circuit of the prosthetic hand is housed inside the arm in "Mechanism and Engineering Evaluation of All-arm Electric Prosthetic Hand" (Tokyo Denki University, Takanori Higashihara) announced at the 11th Biomechanism Symposium. However, in this example, the stored prosthesis and the prosthesis to be controlled are different right and left prostheses, that is, the prosthesis is located far away, so that the problem to be solved by the present invention is solved. Not something. Japanese Patent Application Laid-Open No. 58-143995 also discloses an example in which a lower-level control circuit that receives information from a motor drive circuit or a sensor and appropriately drives and controls the drive circuit is disposed on the limb of a humanoid robot. However, it lacks specificity and similarly does not suggest the solution of the problem to be solved by the present invention.

Further, in the legged walking robot, the degree of freedom to be given to the legs is increased, and at least the position and direction of the landing foot can be freely set regardless of the posture of the body. Six degrees of freedom are required per leg. Therefore, six drive motors are required for each leg. In order to accurately determine the posture of the leg, a potentiometer or encoder for detecting the angle and angular velocity of the joint in real time for each joint is required.For example, in the case of an encoder commonly used, for example, its output is For example, as many as five signal lines are required, and furthermore, the signal lines need a special coating for blocking noise so that noise does not appear on the signal values, and the diameter becomes so large that the signal lines cannot be considered. In the prior art, since the computer that controls the motor based on this signal is stored in the body of the robot, the signal lines are independently remote from the positions of the six motors arranged on the legs. Must be wired to computer over distance. An increase in the length of the signal line means that noise becomes easier to ride on the signal line, so that the signal line must be covered with better performance, that is, a thicker and thicker one. If the wiring becomes too thick, when placed along the joints that move relative to each other, the fear of mutual interference between the wirings also increases, the rigidity of the wiring hinders the free joint movement, the weight increases, and a legged walking robot is realized. To make the property significantly lower. As a method of reducing the fatigue of the wiring, there is a method of sufficiently bending the wiring to bypass the joint. However, this causes a problem of a space for wiring and interference between the wiring and the mechanical member.

[0007] The above problems are mainly caused by the fact that the distance between each encoder and the computer is so long that a joint is present on the way. To solve the problem, the computer must be arranged close to the encoder. However, in a legged walking robot, since the drive motors giving the above-mentioned degree of freedom are widely distributed over the entire legs, this solution cannot be adopted. The encoder signal is needed first to control the drive motor for that joint, and then to calculate the current posture of the robot itself and react to floor reaction forces and inertial forces and gravity acting on the center of gravity. It is also necessary to control the force. The raw signal of the encoder as information necessary for drive control of a single joint may be input to the drive circuit of the motor, and in order to send information for determining the posture and gait of the entire robot to the computer By enriching information, it is possible to reduce the number of wirings required, and it is only necessary to process information that is resistant to noise, for example, by converting an analog signal into a digital signal.

Accordingly, a second object of the present invention is to arrange a drive circuit (driver) for each motor near an encoder, concentrate the input encoder information in this driver, and process the encoder information into information resistant to noise. An object of the present invention is to provide a robot having a structure that proposes a technique of transmitting data to a host computer and that solves the entire layout problem including wiring.

Further, in the prior art, a power line for driving is extended for each motor from a drive circuit of the computer and the motor stored in the body, and the power line has a voltage drop in proportion to its length. In order to reduce this voltage drop, it is necessary to use a thick power line, so that the total length of the power line occupies a considerable weight.

Therefore, a third object of the present invention is to provide a robot having a structure in which the total length of the power line is short.

Further, as will be proposed later in the present invention, in order to accommodate a control device such as a driver in a link mechanism of a robot, not only is the driver board small, but also in order not to increase the inertial weight of the legs. Needs to be reduced in weight. In order to reduce the weight of the driver as much as possible, it is desirable to reduce the amount of hardware constituting the board and to replace the function of the removed hardware with software as much as possible. Also, the remaining hardware requires a heat sink to efficiently cool the power transistor that switches the motor power supply, but this heat sink is not provided specially, but is made using existing parts. If possible, an increase in weight can be prevented.

Accordingly, a fourth object of the present invention is to cope as much as possible with software when constructing a motor driver, and to cope with other parts without specially providing the above-mentioned heat sink, thereby extremely reducing the weight of the driver. An object of the present invention is to provide a robot having a structure that can be made light.

Furthermore, the mechanism and control devices of the robot are sophisticated and precise, and in the assembling process, sufficient workability is taken into consideration, and the inspection after assembling can be easily performed. Must be something. Mounting components at an angle that is difficult to assemble in a place that is difficult to see can cause problems in the market. Good assemblability is the first condition that quick and accurate repair can be performed in the event that repair is required, and is an important requirement for the spread of products. Also, if the recess for storing is to be opened in the leg link as proposed in the present invention, the provision of this opening should not impair the necessary mechanical strength of the leg, The opening must be provided in a position that does not hinder the strength.

Therefore, a fifth object of the present invention is that the above-mentioned substrate can be easily mounted, inspection after assembly can be easily performed visually, and the opening for mounting impairs the mechanical strength. The object is to provide a robot having no structure.

Furthermore, during use of the robot, careless contact with the outside world is expected, and it is quite possible that important parts are damaged by the contact. Important components must be protected from external contact accidents as much as possible. The above-mentioned driver board is delicate, has low mechanical strength, and is easily broken when it comes into contact with the outside, making it difficult to control the robot. In addition, not only mechanical external force from the outside but also dust and substances that inhibit electrical insulation, such as moisture, enter the driver, so that the driver must be effectively protected from such substances.

Therefore, a sixth object of the present invention is to protect the substrate from mechanical external force to prevent breakage,
An object of the present invention is to provide a robot having a structure for blocking and protecting from harmful substances.

[0017]

In order to solve the above-mentioned problems, the present invention has the following construction. The mark described below
In the case of claim 1, the base 24
When provided with a leg portion of the plurality of that will be connected to it, said legs
Joint of consists of (10~20R, L) and at least one link mechanism consisting of two links that are attached through a
Together with the, the link mechanism of the joint drive means Ru is walking by <br/> drive the legs through the (electric motor 36, 40
And etc.), control devices (Con for controlling the operation of the drive means
In the robot 1 including the rollers 60, 68, and 70) , the control device is configured to be housed in at least one of the two links. Claim 2
The link is parallel to the axis of rotation of the joint
A recess in the direction, and the controller is provided in the recess.
It was configured to accommodate the vessel. In claim 3, before
The link is connected to the transistor element 66 of the control device.
It was configured to be adjacent to the sink 76. Claim 4
There is a base 24 and two links connected to it.
Having multiple joints (10-20R, L)
Said leg link mechanism comprising several leg link mechanisms.
Drive means (electric motors 36, 40
Control device for controlling the operation of the
Rollers 60, 68 and 70).
In the robot, the control device is connected to the two links.
At least one of the driving means
A drive source (battery) is housed in the base, and the drive source
The control device was configured to be connected in parallel. Claim 5
In the paragraph, detecting means for detecting the output of the driving means
(Encoder) and output the detection means
It was configured to send it to the control device. Claim 6
That is, a second control for controlling the driving means is provided on the base.
A control device (host controller 30) is provided and the link
To allow serial communication with control equipment housed in
Well configured. According to claim 7, the link has a cross section.
It was configured to be Type I.

[0018]

[Function] Since the control device is accommodated in the link, the space of the robot with a limited mounting space can be effectively used, and the wiring and work problems can be solved, and the mechanical strength can be improved. It is sufficient and does not lack protection issues.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to a bipedal walking mobile robot as an example of a robot. FIG. 1 is an explanatory skeleton diagram showing the robot 1 as a whole, and has six joints (axes) on each of the right and left legs (for convenience of understanding, each joint (axis) is electrically driven to drive it). Motors). The six joints (axes) are, in order from the top, joints 10R and 10L for turning the leg of the crotch (right side is R, left side is L. The same applies hereinafter), and forward and backward directions of the crotch (robot traveling direction). Joints 12R and 12L for exercise, joints 14R and 14L for exercise in the roll direction, joints 16R and 16L for anteroposterior movement of the knee, joints 18R and 18L for anterior and posterior exercise of the ankle, and exercise for the same lateral movement Joint 20R, 2
It is 0L. At its lower part, legs 22R, 22L are attached, and at the top, a body (base) 24 is provided. The thigh link and the knee are thigh links 26R and 26L.
The knee and the ankle are connected by the lower leg links 28R and 28L.

Here, it is assumed that two joints in the front, rear, left and right directions are arranged at right angles in the crotch part and the ankle part, and their axes intersect at one point in the space. As is clear from the figure, the joints for the fore-and-aft movement of the hip, knee, and ankle joints are arranged so that their rotation axes are parallel to each other, no matter how the other three degrees of freedom behave. Are arranged so as not to change. In the hip joint, a third degree of freedom for rotating the entire leg link is provided, and the rotation axis is arranged so as to be orthogonal to the two axes at the intersection of the two axes. The torso 24 includes a host controller 30 including a computer for pre-processing of visual means (not shown) or a higher-level computer for setting a gait, and a power source of the computer and a joint drive electric motor. A certain battery or the like is accommodated.

FIG. 2 is a longitudinal sectional view of the thigh link 26 (only one leg link will be described below because it is a left-right contrast). FIG. 3 is a side view of the thigh link 26 viewed from the left side. 4 is a side view of the same as viewed from the right side, and FIG. 5 is a sectional view taken along line VV of FIG. In the figure, the upper yoke portion 32 of the thigh link 26 is connected to the joint 12 in the hip joint.
When the robot is assembled as a robot, the entire leg link swings in the front-rear direction around the axis 34. The electric motor 36 for the fore-and-aft movement is housed in the yoke portion 32, and its output is increased by a harmonic reducer (trade name) 38 to give a swing moment to the thigh link 26. Thigh link 26
A second electric motor 40 is arranged at a position slightly above the center of the knee joint. The output of the second electric motor 40 is increased by a second harmonic reducer 44 provided inside the knee joint 16 via a belt 42, and the lower leg link 28 is A relative rotational movement is performed on the thigh link 26 in the front-rear direction about the axis 45.

The cross section of the thigh link 26 is shown in FIG.Like
In addition, it has a roughly I-shaped shape, and one of the recesses (FIG. 2)
Drive the electric motors 36 and 40 respectively.
Drivers 50 and 52 for operating are mounted on substrates 54 and 56
Placed on the thigh link 26 with its board
It is fixed with several screws as shown. AlsoThighLink2
6The recess on the opposite side of the I-shaped cross section of FIG.Like
To send the necessary command signals to the drivers 50 and 52
The controller 60 is similarly fixed with screws.Thigh
Both these recesses in the I-section of the link 26 are shown in FIG.
Similarly, fix the drivers 50 and 52 and the controller 60
And then covered with covers 62 and 64 made of plastic material
It is. Covers 62 and 64ThighProvided on the link 26 side
The flanges 26a, 26b are fitted without gaps, and
It is fixed at a predetermined position by elasticity. Of the covers 62 and 64
Plastic materials are materials that have the property of blocking electromagnetic waves
Is selected from Such materials are known and difficult to obtain
Then mold the wire mesh into plastic material and make it
Is also good.

FIG. 6 is a circuit diagram showing an example of the driver circuit 50 (or 52). Further, FIG.
A block diagram of a lower-level controller 60 comprising a microcomputer of 16 bits (internal 16 bits) is shown. The illustrated driver itself is a known driver, and includes two switching FET elements 66 for forward and reverse rotation. Also, as is clear from FIG. 7, the two driver circuits 50, 52
Is controlled by one controller 60. What is shown is for controlling the electric motors located at the joints 12 and 16, and therefore, as shown in FIG. 1, for controlling the drivers for the two electric motors further located at the foot joints 18 and 20. A second controller 68 is provided at an appropriate position on the lower leg link 28, and a third controller 70 for controlling a driver for an electric motor of the remaining joints 10 and 14 of the hip joint is provided on the body 24.

Here, as is apparent from FIG. 7, the detecting elements, ie, encoders for detecting the rotation amounts of the electric motors 36 and 40, the thigh link 26 and the lower leg link 2
The output of the limit switch for detecting the rotation limit of the motor 8 and the current monitor amplifier for monitoring the amount of current supplied to the FET transistor 66 is supplied only to the lower controller 60 and the host accommodated in the upper body 24 That is, it is not supplied to the controller 30. That is, the detection outputs of these detection elements are processed by the lower-level controller 60, based on which the operation of the two drivers 50 (52) is controlled. That is, it is configured to perform serial communication. As a result, the signal line of the detection element is not sent to the body 24 across the joint, the total length is shortened, the noise countermeasures are reduced, and the above-described inconvenience on wiring is eliminated. Further, by causing the lower-level controller 60 to perform the processing of the detection output, the load on the host controller 30 is reduced.
0 can be constituted by a relatively low-level microcomputer of, for example, about 32 bits, and its size, weight, power consumption, and price can be reduced. Further, since the lower controller 60 and the host controller 30 can communicate freely by serial communication, the lower controller can send the processing result of the detection output to the host controller as a digital signal as necessary, The number of signal lines can be reduced as compared with the case where communication is performed.

Further, returning to FIG. 2 and thereafter, the driver 50 (5
The features of the arrangement structure 2) will be described. First, as shown in FIG. 2, since two drivers 50 and 52 are adjacent to each other, when power is supplied from the battery housed in the body 24, they are connected in parallel to share the input side, and the power line is connected. 7
This is to solve the above-mentioned problem on wiring by reducing the number of lines. As shown in FIG. 5, the FET transistor 66 is attached to the position shown in the drawing via a mounting jig 74, and a heat sink 76 for cooling the FET transistor 66 is arranged so as to contact the wall surface of the thigh link 26. It is.
That is, the thigh link 26 itself was used as a heat sink. As a result, the thigh link 26 is a relatively long member as shown in FIG. 2, and its side surfaces 26c and 26d are always in contact with the outside air. Sufficient heat dissipation volume can be given to the two FET transistors 66 used in a single operation. As a result, the size and weight of the heat sink 76 inherent in the driver 50 (52) can be reduced.
As shown in the figure, in order to store the driver's board in the movable link, not only the board must be small, but also the inertial weight of the leg link needs to be as small as possible. Could be achieved.

A further characteristic feature is that the driver 50 (5
Since 2) is stored in the thigh link including the lower controller 60 described above, even if a mechanical external force is applied, the link becomes a protective material and damage is avoided. Also, as shown in FIG. 5, the thigh link 26 has an I-shaped cross section. That is, the I-shaped cross section is originally
Since it has a sufficient section modulus for bending in one direction, the direction that is strong in this bending is arranged in accordance with the traveling direction (front-back direction) of the robot (indicated by the arrow in the figure) and sufficient machine This is to ensure strength and rigidity. Further, as described above, the storage portion is formed of a cover 62 made of a plastic material,
Since it is covered with 64, intrusion of dust, moisture and electromagnetic waves can be easily prevented. In addition, during the storage operation, the board and the like can be easily assembled with the covers 62 and 64 removed, and maintenance is easy, and visual failure diagnosis and the like are also possible. Furthermore,
When the cover is made of a transparent material, it can be seen from the outside.

As described above, this embodiment is robust and highly rigid in the front-rear direction (traveling direction) for mainly transmitting the driving force for walking in the cross-sectional shape of the leg link of the legged walking robot. The I-shape is promising, and the recess accommodates two drivers for driving the motor. The lower controller that controls the drive is also accommodated, and the detection output is processed by the lower controller to reduce the burden on the host controller. In addition, since the driver and the power supply are connected in parallel to reduce the number of power lines, the mounting space for the control device in the leg link mechanism can be effectively secured, and the total power lines can be secured. Inconvenience on wiring including reduction of extension can be solved. In addition, the link is used for cooling the transistor of the driver to reduce the weight of the driver, and is housed in a link that can be easily accessed from the outside, so that the workability is excellent and the protection against external force is also lacking. Nothing.

In the embodiment described above, the thigh link 2
FIG. 6 shows only an example in which a member having an I-shaped cross section is used and housed therein, but the case where the member is housed in the lower leg link 28 is exactly the same. Further, the drivers 50, 5
2 is shown as an example, the drivers 50, 5
2 and the lower controller 60 may be reversed, or the drivers 50 and 52 may be separately arranged on both sides.

FIG. 8 shows a second embodiment of the present invention, in which the link 26 has a sectional shape as shown in the figure instead of the I-shaped material. In this case as well, it goes without saying that the driver boards and the like are housed in the recesses on both sides and are arranged in accordance with the robot traveling direction indicated by the arrow.

FIG. 9 shows a third embodiment of the present invention, in which a link 26 having an H-shaped cross section as shown is used. The remaining points are not different from the second embodiment.

FIG. 10 shows a fourth embodiment of the present invention, in which a link 26 having a pipe-shaped cross section as shown is used. The remaining points are 2nd and 3rd
It is not different from the embodiment.

It should be noted that the present invention is not limited to the above-described embodiment.
Although the description has been given of the legged walking robot of the legged walking, the invention is not limited thereto. The present invention is also applicable to an installation type robot generally called an industrial robot.
This is also applicable to a legged walking robot having more than two feet.

[0033]

In the claim 1 according to the present invention, a substrate provided with a leg portion of the plurality of that will be connected to it, the leg portion via a joint
Together composed of the two consists of links of at least one link mechanism coupled, drive means Ru is walking by driving the leg through the joint of the link mechanism, the operation of the drive means In a robot including a control device for controlling, the control device is configured to be accommodated in at least one of the two links, so that the space of the robot can be effectively used, and wiring and workability are improved. It is suitable and has sufficient mechanical strength so that its protection is not lost.

[0034] In the robot according to claim 2 wherein, said link is intended that a recess in a direction parallel to the axis of rotation of the joint, since as configured to accommodate the control devices in the recess, the link The strength of the entire robot can be increased by matching the direction of high rigidity to the direction of travel of the robot, and by using a control device in the recess on the side of the robot, the robot's space can be used effectively, and the control device is also used. Can be sufficiently protected.

In the robot according to the third aspect, since the link is configured to be adjacent to the heat sink of the transistor element of the control device, the link itself can be used as a heat sink, and the control device is small and lightweight. This facilitates the accommodation and suppresses an increase in inertial weight.

[0036] In the fourth aspect, wherein, a substrate and connected thereto, composed of a plurality of leg link mechanism having a plurality of joints for coupling the two links, the joint of the leg link mechanism In a mobile robot including a driving unit for driving and a control device for controlling the operation of the driving unit, the control device is housed in at least one of the two links, and a driving source of the driving unit is provided. were housed in the base, said driving source and said control device from the fact connected in parallel, it is possible to effectively utilize the space in the mobile robot installation space in the base body is limited, also the power line Since the total length is reduced, a wiring problem can be solved. In addition, since it is accommodated in the leg link, workability and strength are also excellent.

According to a fifth aspect of the present invention, in the robot according to the fifth aspect of the present invention, the detection means for detecting the output of the driving means is provided, and the output of the detection means is sent to the control device. Can be reduced and noise countermeasures can be facilitated.

In the robot according to the sixth aspect, a second control device for controlling the operation of the driving means is provided on the base, and serial communication is possible with the control device accommodated in the link. With such a configuration, the wiring of the detection means can be simplified, and the capacity, price, shape, and weight of the substrate can be reduced by reducing the load on the second control device and realizing the microcomputer. Space can be effectively used.

In the robot according to the present invention, since the link is configured to have an I-shaped cross section, the direction of high rigidity is made to coincide with the direction of travel of the robot, thereby increasing the strength of the entire robot. The side recess can be used as a storage location.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an entire robot according to the present invention.

FIG. 2 is an explanatory longitudinal sectional view of a thigh link of the robot shown in FIG. 1;

FIG. 3 is a side view of the link in FIG. 2 as viewed from the left side.

FIG. 4 is a side view of the link in FIG. 2 as viewed from the right side.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a circuit diagram of the driver shown in FIG. 2 and subsequent figures;

FIG. 7 is an explanatory block diagram of a lower controller shown in FIG. 2 and subsequent figures;

FIG. 8 is a cross-sectional view of a link material showing a second embodiment of the present invention.

FIG. 9 is a cross-sectional view of a link material showing a third embodiment of the present invention.

FIG. 10 is a sectional view of a link material showing a fourth embodiment of the present invention.

[Explanation of symbols]

1 legged walking robot (bipedal walking robot) 10R, 10L leg rotation joint (axis) 12R, 12L crotch pitch direction joint (axis) 14R, 14L crotch roll direction joint (axis) 16R , 16L Knee pitch joints (axes) 18R, 18L Ankle pitch joints (axes) 20R, 20L Ankle roll joints (axes) 22R, 22L Feet 24 Body 24 Host controller 50 , 52 driver 54, 56 driver board 60, 68, 70 lower controller 62, 64 cover 66 FET transistor 72 power line 76 heat sink

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-1844781 (JP, A) Fully open sho 59-153074 (JP, U) Fully open sho 59-86992 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B25J 5/00 B25J 13/00 B25J 19/00

Claims (7)

(57) [Claims] 1. A substrate and, a plurality of legs that will be connected thereto
Comprising a, it is composed of at least one link mechanism consisting of two links which the legs are joined via a joint
Rutotomoni, driving means Ru is walking by driving <br/> moving the legs through the joints of the link mechanism, a robot comprising a control device for controlling the operation of the drive means, said control A robot, wherein a device is accommodated in at least one of the two links. Wherein are those comprising a recess in the direction in which the link is parallel to the axis of rotation of the joint, according to claim 1 wherein the robot, characterized in that accommodates the control device in the recess. 3. The robot according to claim 2, wherein the link is adjacent to a heat sink of a transistor element of the control device. 4. A driving means for driving a joint of the leg link mechanism, comprising : a base; and a plurality of leg link mechanisms connected to the base and having a plurality of joints connecting the two links. And a control device for controlling the operation of the means.
Robot accommodates at least one of number of links, the houses a driving source of the driving means to the substrate, characterized in that connected in parallel said drive source and said control device. With wherein providing a detection means for detecting an output of said drive means, said detecting means robot according to claim 4, wherein wherein the output is characterized by being configured to deliver to the control device. 6. The apparatus according to claim 4, wherein a second control device for controlling said driving means is provided on said base, and serial communication is possible with a control device accommodated in said link. robot. 7. A robot according to any one of 6 Claims 1 wherein, wherein the link is a sectional type I.