JP4006528B2 - Casting manipulator - Google Patents

Description

  The present invention relates to a casting manipulator that uses a new mechanism having a soft chain to project a gripping member by utilizing the inertial force and centrifugal force of the gripping member connected to a robot arm by “throwing (casting)”. The present invention relates to a movement control device for a gripping member in a robot work space.

  There is a method of using a robot arm as a method of automatically moving a target object from an arbitrary position to another target position using a mechanical system, but the target object is within the reach (reach area) of the hand of the robot arm. If not, the target object cannot be operated. The reaching area of the robot arm is considered as one index indicating the performance of the robot. In particular, a robot having a wider reaching area is required for work in a large space such as outdoor work.

  In order to make the reach area of the robot as wide as possible, a mechanism in which the length of the link constituting the arm is made as long as possible is conceivable. However, since the conventional technique uses a rigid link, the longer the link, the larger the arm weight increases the load on the output of the drive source. Therefore, the longer the length of the link, the larger the drive source is required, which increases the weight of the entire robot, the higher the inertia of the link, the lower the movement speed of the arm, and the energy for the work. The problem arises that the efficiency is further reduced. Currently, the length of a robot arm developed for working outdoors is at most several meters (see a in FIG. 1).

  Next, there is a method in which a robot arm is mounted on a moving mechanism to expand the reach area of the robot. As a moving mechanism, mechanisms such as wheels, crawlers, and legs that move in contact with the ground surface have been developed, and there is a conventional technique in which a robot arm is mounted on these moving mechanisms (see b and c in FIG. 1). However, since the movement mechanism in contact with the ground surface is affected by the shape and properties of the ground surface, there is a problem that movement in rough areas such as steep slopes, depressions, and swamps is very difficult in the prior art.

  In addition, a moving mechanism represented by unmanned aircraft such as helicopters, airplanes, and airships that move without touching the surface of the earth has been developed. However, there is no practical machine that has a robot arm on this moving mechanism. Even if a robot arm is mounted on a mechanism that moves without touching the ground surface, the weight of the moving mechanism is small, the attitude control of the aircraft is difficult, and contact with the environment as represented by a crash. There are problems such as the entire system going down easily.

  Therefore, in the robot arm mechanism, a method of using a linear, variable-length, lightweight and flexible link in place of some rigid links can be considered. For example, as shown in FIG. 1 d, while the length of the linear flexible link 11 is extended from the robot body 10, the gripping member 12 ahead is projected (casting) onto the target object 13, and the linear This is a method of controlling the movement of the gripping member 12 in the air by the tension of the link 11 and gripping the target object 13 (in this specification, the type of the mechanical system that realizes this type of method is referred to as “casting manipulator”). . Using this method, it is possible to have a very wide reach area with a simple mechanism and compact size, and it is energy efficient and can repeatedly perform high-speed movements, so it has excellent fault tolerance. There is an advantage.

  However, in the conventional system, the linear flexible link 11 is fixedly coupled to one end of the gripping member 12, so that when the motion of the gripping member 12 is controlled by tension, the gripping member translates in the vertical plane. And there was a problem that the rotational motion could not be controlled independently. Further, in order to stably hold the target object 13 by the holding member 12, it is necessary to appropriately control the position / posture of the holding member 12 and the translation speed / rotation speed. Therefore, there is a problem that control for stably grasping the target object 13 by the grasping member 12 is not easy only with the tension of the single linear flexible link 11. For example, as shown in FIG. 2, when the direction of the tension and the direction of the long axis of the gripping member 12 are close to a right angle, the effect of the tension is minimal with respect to the translational motion of the gripping member 12, and The effect is maximized. Therefore, a larger rotational motion is generated as the tension is increased, and thus problems such as difficulty in gripping an object and entanglement of the linear flexible link 11 with the gripping member 12 arise. Therefore, when the direction of tension and the direction of the long axis of the gripping member are close to a right angle, there is a restriction that a large tension cannot be applied, and control for gripping an object becomes difficult.

  In addition, since the currently developed system can control only the movement in the determined vertical plane, if the movement of the gripping member occurs in the direction perpendicular to the vertical plane due to the influence of disturbance, the movement There is a problem that cannot be controlled.

  Conventionally, when the linear flexible link is fixedly coupled to one place other than the center of gravity of the gripping member, the movement of the gripping member moving in the space is controlled by the tension of the linear flexible link. In view of the fact that the movement of the gripping member outside the vertical plane cannot be controlled, by using a plurality of linear flexible links or using a single linear flexible link, It is an object of the present invention to provide a casting manipulator having a gripping member motion control device that can control the translational motion of the gripping member independently of the rotational motion by the tension of each link by making it movable to a position.

(1) In order to achieve the above object, a casting manipulator according to the present invention projects a gripping member onto a target object, and in the casting manipulator configured to grip and collect the target object, a linear shape wound around a feeding / winding mechanism One end of the flexible link is connected to the gripping member, and the translational motion and the rotational motion of the projected gripping member in the air can be controlled simultaneously or independently only by the tension of the linear flexible link. To do.
(2) Further, the casting manipulator of the present invention couples the linear flexible link for translational motion control to the gravity center position of the gripping member in (1) above, and translates and rotates at the end opposite to the hand of the gripping member. It is characterized by connecting linear flexible links for motion control.
(3) Further, the casting manipulator of the present invention is provided with a bar in a direction perpendicular to the plane in which the center of gravity moves through the center of gravity of the gripping member in the above (2), and linear flexible for translational motion control at both ends of the bar It is characterized by connecting links.
(4) Further, the casting manipulator of the present invention has a slider mounted on the gripping member on the straight line connecting the center of gravity of the gripping member and the hand of the gripping member in (1), and the linear flexible link on the slider. The connecting portion between the gripping member and the gripping member is formed to be movable.
(5) Moreover, the casting manipulator of the present invention is a gripping member that periodically changes the tension of the linear flexible link coupled to the gripping member or the position of the fulcrum in any of the above (1) to (4). A projecting operation of the gripping member is performed by giving a rotational motion to.
(6) In the casting manipulator of the present invention, the position of the mechanism for feeding and winding the linear flexible link for translation / rotation motion control in any one of the above (1) to (5) is variable. Features.
(7) In the casting manipulator of the present invention, the gripping member according to any one of the above (1) to (6) is mainly formed of a main body part, an attacker corresponding to a palm part, and a plurality of fingers. It is designed to close the finger when it collides with an object.

The present invention has the following excellent effects.
(1) It can have a very wide reach area with a simple mechanism, a compact size, and a small drive source.
(2) Unaffected by the shape and properties of the ground surface.
(3) It has high energy efficiency, can repeatedly perform high-speed movement, and has excellent fault tolerance.
(4) Since the translational motion of the gripping member can be controlled independently of the rotational motion, the motion control of the gripping member moving in the space is facilitated.
(5) The translational motion can be controlled at any position in the space without considering the dependency between the translational motion and the rotational motion of the gripping member.

  The best mode for carrying out a casting manipulator according to the present invention will be described below with reference to the drawings.

  FIG. 3 shows a rescue operation at the time of a disaster, particularly a rescue operation for a person who has suffered a flood, by the robot 10 having the motion control device for the gripping member 12 coupled to the linear flexible link 11 in the casting manipulator according to the present invention. FIG. 4 shows a recovery operation at the time of a disaster, particularly a removal operation of a collapsed house or the like by the robot 10.

FIG. 5 shows basic operations related to gripping / recovering the target object in the operation (casting manipulation) of the gripping member by the casting manipulator, which is divided into the following five operations.
(A) Rotating operation: The entire manipulator is swung, and the movement necessary for the gripping member to reach the target object is given.
(B) Projection operation: The restraint of the linear flexible link is released at an appropriate timing, and the gripping member is projected toward the target while the linear flexible link is fed out.
(C) Trajectory control operation: Controls the position / posture of the gripping member being projected so that the target object can be grasped.
(D) Grasping operation: Grasping the target object.
(E) Recovery operation: In order to recover the gripped target object, the winding of the linear flexible link and the movement of the rigid link are performed simultaneously.

  The present invention focuses on the operation of taking the target object of (a) to (d) above, projects the gripping member after moving the gripping member, and moves the gripping member from the projection position to the target position. The present invention relates to a device that controls the movement of a gripping member until a target object is gripped. Details will be described below.

[Gripping member projection method]
The method of projecting the gripping member is roughly classified according to whether the gripping member translates or rotates during projection. The characteristics of each are as follows.
(1) Rotational motion: In the rotational motion as shown in FIG. 6A, a force can be repeatedly applied to the gripping member by a periodic motion. Therefore, a large kinetic energy can be generated with a small driving force.
(2) Translational motion: In the translational motion as shown in FIG. 6 (b), the distance over which a force can be continuously applied is shorter than the rotational motion. Therefore, a large driving force is required to generate an instantaneous force such as a spring, air pressure, and water pressure.

[Grip member motion control method]
As a main method of obtaining a force for controlling the movement of the gripping member in the air, a method using a device that generates a force built in the gripping member and a method of applying a force from the outside of the gripping member via a linear flexible link There are two. Examples of the force generating device built in the gripping member include a thruster, a reaction wheel, a control moment gyro, and the like. However, an increase in the mass and size of the gripping member and a decrease in impact resistance are problems. In addition, such a device is generally expensive, and when the gripping member cannot be recovered, the cost increases when the linear flexible link is cut and a new gripping member is mounted or when the device itself is damaged. End up. Therefore, a method of applying a force to the gripping member from the outside via the linear flexible link is effective, and if the device is built in the gripping member, it is not possible to generate the force via the linear flexible link. Therefore, it is necessary to consider an inexpensive, lightweight and compact device that assists the method of applying force to the gripping member. FIGS. 7A and 7B show examples of methods in which the translational motion can be controlled independently of the rotational motion.
In FIG. 7A, the translational / rotational motion is controlled by the linear flexible link a coupled to a point other than the center of gravity of the gripping member, and only the translational motion is performed by the linear flexible link b coupled to the center of gravity of the gripping member. It is a method that can be controlled.
FIG. 7B shows the slider 18 mounted on the gripping member on the straight line connecting the center of gravity of the gripping member and the hand 15 of the gripping member, and the linear flexible link and gripping member connecting portion 24 on the slider 18. It is a method to control so that can move. Only the translational motion can be controlled by moving the coupling part to the center of gravity. Further, by changing the distance between the coupling portion and the center of gravity, it is possible to control the rotational motion by changing the effect of the tension on the rotational motion.

図８に、繰り出し・巻き取り位置制御法としてロボットアームを用いた場合の各方式のシステムの概略を示す。
全てのタイプに関して、「線状柔軟リンクの繰り出し・巻き取り位置の制御装置（ロボットアーム）と把持部材１２を繋ぐ線状柔軟リンク１１−３」と「把持部材１２の重心Ｇを通る長軸」は同一鉛直面内を運動する。ただし、必要に応じて線状柔軟リンク１１−１、１１−２の張力やロボットアームによって、鉛直面に垂直な方向の運動を生成することが可能である。また、図８のタイプＣ及びタイプＤでは並進運動による投射方法としてバネを用いた方法を示しているが、水圧、空気圧、火薬などの瞬発力を用いる方法に置き換えることも可能である。 〔System configuration〕
Various systems can be configured by a combination of the gripping member projection method shown in FIG. 6, the linear flexible link and gripping member coupling method shown in FIG. 7, and the feeding / winding position control method.
The combinations of the methods are summarized as follows.

FIG. 8 shows an outline of a system of each system when a robot arm is used as a feeding / winding position control method.
For all types, "linear flexible link 11-3 connecting linear flexible link feeding / winding position control device (robot arm) and gripping member 12" and "long axis passing through center of gravity G of gripping member 12" Move in the same vertical plane. However, it is possible to generate a motion in a direction perpendicular to the vertical plane by the tension of the linear flexible links 11-1 and 11-2 and the robot arm as necessary. 8 shows a method using a spring as a projecting method by translational movement, but it can be replaced with a method using instantaneous force such as water pressure, air pressure, gunpowder.

[Projection method by rotary motion]
Here, the details of the projection method based on the rotational motion will be described. Details of the projection method by translational motion are omitted.
In Type A, exercise as shown in FIG. 9 is performed. As shown in FIG. 9A, the bar 14 passing through the center of gravity G of the gripping member 12 moves around a straight line passing through the line guides 5 and 5 indicated by dotted lines so as to be parallel to the dotted line.
Moreover, it can be divided into a method of projecting by a multi-rotation motion as shown in FIG. 10 (a) and a method of projecting by a periodic swing motion like a pendulum as shown in (b).

Next, a method for generating rotational motion will be described. The following two methods can be considered as a method for generating the rotational motion in Type A.
(1) Periodically changing the tension of the linear flexible link.
(2) Periodically changing the position of the line guide, which is a fulcrum of rotational movement.
First, the method (1) is a method using the so-called “principle principle”. When the pendulum motion is close to the center line of the pendulum movement (dotted line in the figure) as shown in FIG. In this method, the linear flexible link is drawn so as to be close to the fulcrum of movement, and when it is far from the center line, the linear flexible link is loosened so as to be away from the fulcrum. By controlling the tension of the linear flexible link so that the position of the center of gravity of the gripping member as shown in FIG. 11 draws an 8-character shape, the swing angle of the pendulum motion gradually increases, and the pendulum motion is shifted to the multi-rotation motion. Is also possible. However, when the initial position of the gripping member is on the dotted line in FIG. 11, even if the tension is controlled, it moves only up and down and no pendulum motion is generated. In this case, it is necessary to give the initial movement of the gripping member with a robot arm or the like.
In the method (2), the position of the line guide in FIG. 9A is periodically moved in one direction perpendicular to the dotted line in FIG. 9 and the line guide is periodically rotated around the dotted line in FIG. There is a method to make it. By each method, the system resonates and starts periodic oscillating motion and rotational motion. It is also possible to mount a robot arm between the end of the bar passing through the center of gravity of the gripping member and the line guide, and generate a periodic swinging motion and rotational motion of the system by the pendulum motion of the arm.
Next, in Type B, as in Type A, it is possible to generate a rotational motion by controlling the tension, but the gripping member and the robot arm may interfere with each other. FIG. 12 shows a method for generating the rotational motion of the system by shaking the robot arm. Although the robot arm is for controlling the feeding / winding position of the linear flexible link, in Type B, the robot arm can be used for the projection of the gripping member and can be used with one mechanism. Multiple functions can be realized.

[Necessity of motion control of gripping members in the air]
In some cases, it is necessary to control the movement of the gripping member projected to the target point. For example, after the projection, if the gripping member in flight is subjected to a disturbance, it may be out of the target trajectory. At this time, the control of only the projection cannot correct the trajectory and cannot reach the target point. Therefore, it is necessary to correct the trajectory by a force through the linear flexible link. Further, when the target point is behind the obstacle as shown in FIG. 13, the parabolic trajectory such as the dotted line interferes with the obstacle and cannot reach the target point. Therefore, it is necessary to project the object farther than the target point and to reach the target point in a trajectory that wraps around the obstacle by controlling the movement of the gripping member in the middle.

[Method of applying force to the gripping member in the air]
As an example of a method for applying a force to the gripping member via the linear flexible link, the following method as shown in FIG. 14 can be considered.
(1) Swing of rigid link {Fig. 14 (a)}
(2) Winding of the linear flexible link by the drum mechanism {FIG. 14 (b)}
(3) Restriction of extended linear flexible link {FIG. 14 (c)}
(4) Combination of the above (1) to (3) In order to enhance the effect of projecting the gripping member far away, it is necessary to feed the linear flexible link at high speed and with as little tension as possible. Therefore, a method using a brake mechanism for restraining the linear flexible link corresponding to the above (3) is proposed as a simpler and more practical method.
During the flight of the gripping member, the linear flexible link is unwound from the drum as shown in FIG. 15. The movement is restrained. At this time, it is considered that the gripping member behaves as if it collides with a virtual wall generated in a direction perpendicular to the linear flexible link. At this time, the movement of the gripping member during the flight is changed by the striking force transmitted from the linear flexible link to the gripping member, and the position and posture can be controlled.

[Amount that can be controlled by the brake]
There is a method of controlling the following variables as a method of braking the linear flexible link.
(1) Time to start braking (2) Duration of braking (3) Brake force Controlling brake force is controlling sliding friction, and the behavior at that time is very complicated . Therefore, here, a case is considered in which the braking force is not controlled, but a sufficiently constant braking force is applied so that the influence of slipping can be ignored. That is, consider controlling the variables (1) and (2).
First, FIG. 16 shows a brake input chart relating to the constraint start time of (1).
The chart shows the brake input with respect to the time since the projection. The time at the projection point is 0, and the time at the constraint point is tb. By controlling the restraint start time tb, it is possible to control the restraint position, that is, the position where the movement of the gripping member is changed.
Next, in addition to (1), the constraint duration which is a variable of (2) is shown in the chart of FIG.
The restraint continuation time Δtb is the time from the start of braking to the stop, and is the time during which the linear flexible link is kept restrained. The brake input at this time has a pulse shape as shown in FIG. When the restraint duration time Δtb is large, the rebound of the gripping member is large, and when it is small, the bounce is small. It is possible to control the amount of rebound of the gripping member according to the constraint continuation time.
The position where the movement of the gripping member is changed and the amount of rebound of the gripping member can be controlled by two variables, that is, the constraint start time tb and the constraint continuation time Δtb.

重心回りの回転速度

の計６変数で表せる。一方、ブレーキ制御ではｔｂとΔｔｂの２つの制御変数がある。したがって、１回のブレーキ制御では、把持部材の運動を完全に制御することはできない。そこで、複数回のブレーキを行うことを考える。例えば、３回のブレーキ制御を行うことにより、制御変数の数の合計が６つになる。図１８に３回のブレーキ制御時のブレーキ入力のチャートを示す。
図１８に示すように、ｔｂ（1），Δｔｂ（1）、ｔｂ（2），Δｔｂ（2）、ｔｂ（3），Δｔｂ（3）の６つの制御変数を扱うことができる。ただし、ブレーキを同時に３回行うことは不可能なので、時々刻々の把持部材の運動を制御できないが、３回目のブレーキが終了後に、目標とする把持部材運動を生成することができる。 [Multiple brake control]
The movement of the gripping member in the vertical plane includes the position of the center of gravity (x, y), the angle around the center of gravity (posture) φ, and the translational speed of the center of gravity.

Rotation speed around the center of gravity

It can be expressed by a total of 6 variables. On the other hand, in the brake control, there are two control variables, tb and Δtb. Therefore, the movement of the gripping member cannot be completely controlled by one brake control. Therefore, consider performing braking several times. For example, by performing brake control three times, the total number of control variables becomes six. FIG. 18 shows a chart of brake input at the time of three times of brake control.
As shown in FIG. 18, six control variables tb (1), Δtb (1), tb (2), Δtb (2), tb (3), and Δtb (3) can be handled. However, since it is impossible to brake three times at the same time, it is impossible to control the movement of the gripping member from moment to moment. However, after the third brake is finished, a target gripping member movement can be generated.

FIG. 19 shows an embodiment of a motion control mechanism for controlling the motion of the gripping member 12, and means for projecting the gripping member 12 is omitted. Refer to FIG. 9 for the projection method.
In this embodiment, the movement of the gripping member 12 is controlled from the outside of the gripping member 12 by the plurality of linear flexible links 11-1, 11-2, and 11-3 without mounting the drive source on the gripping member 12. The mechanism was realized. Specifically, linear flexible links 11-1 and 11-2 for translational motion control are coupled to both ends of the bar 14 passing through the center of gravity G of the gripping member 12 and perpendicular to the center of gravity motion. This is a mechanism in which a linear flexible link 11-3 for translational / rotational motion control is coupled to an end 16 in a direction opposite to the hand 15. Thereby, weight reduction of the holding member 12 was realizable. Because the flexible flexible links 11-1 and 11-2 are wound around the feeding / winding mechanisms 1 and 2, respectively, the respective turning radii are the same, and both the rotating shafts 17 and 17 are coupled. At the same time, linear flexible links of the same length can be fed and wound. Further, when the rotary shafts 17 and 17 are disconnected and the feeding / winding mechanisms 1 and 2 are independently controlled, it is possible to control the movement of the gripping member 12 other than the movement in the vertical plane.
The feeding / winding mechanism 3 and the slider 18 are mechanisms for controlling the translation / rotation motion of the gripping member 12 via the linear flexible link 11-3.
When the direction of the linear flexible link 11-3 coincides with the direction of the long axis of the gripping member 12, the slider 18 cannot control the rotational movement of the gripping member 12, so the linear flexible link 11-3 It is a mechanism for changing the feeding / winding position.

  FIG. 20 shows the gripping member 12. The gripping member 12 is mainly composed of a main body 12-1, an attacker 19 corresponding to the palm portion, and a plurality of fingers 21, and when the attacker 19 corresponding to the palm portion and the target object 13 collide, the hook 20 is released and the force of the spring 23 is released. Thus, the four fingers 21, 21, 21, 21 are passively closed. Even when the finger 21 is open, the joint at the base of the finger 21 is free in the opening direction, so that the impact force can be reduced against the collision between the finger 21 and the target object 13. Further, as shown in the figure, the attacker 19 is provided so as to be able to protrude and retract with respect to the main body 12-1, and has a structure in which the shock is buffered by the buffer spring 22.

It is a figure for demonstrating the outline of the conventional manipulator comprised only by the casting manipulator and rigid body link of this invention. It is a figure for demonstrating the state with which the linear flexible link was couple | bonded except the gravity center position of the holding member. It is a figure which shows the application example of the casting manipulator of this invention. It is a figure which shows the application example of the casting manipulator of this invention. It is a figure explaining the basic operation | movement of casting manipulation. It is a figure explaining the projection method of a holding member. It is a figure which shows the coupling | bonding method of a linear flexible link and a holding member. It is a figure which shows the various system structure by the combination of the projection method of a holding member, the coupling | bonding method of a linear flexible link and a holding member, and a feeding / winding position control method. It is a figure which shows the projection method by the rotational motion in Type A. It is a figure which shows the projection by rotational movement and the projection by rocking | fluctuation movement. It is a figure explaining the method of producing | generating the rotational motion using the principle of a swing. It is a figure which shows the method of producing | generating the rotational motion of the system by the swing of a robot arm. It is a figure which shows the necessity of the movement control of the holding member in the air. It is a figure which shows the example of the method of giving force to a holding member via a linear flexible link. It is a figure explaining the change of the motion of the holding member by a striking force. It is a figure which shows the method of controlling a restraint start time as a method of braking a linear flexible link. It is a figure which shows the method of controlling restraint continuation time as a method of braking a linear flexible link. It is a figure which shows the example of multiple brake control. It is the schematic which shows one Example of the movement control mechanism which controls the movement of a holding member. It is a figure which shows an example of the structure of a holding member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Feeding / winding mechanism 2 Feeding / winding mechanism 3 Feeding / winding mechanism 4 Pulley 5 Line guide 6 Position control device of feeding / winding mechanism 10 Robot body 11 Linear flexible link 12 Gripping member 13 Target object 14 Bar 15 Hand 16 End of gripping member 17 Rotating shaft 18 Slider 19 Attacker 20 Hook 21 Finger 22 Buffer spring 23 Spring 24 Joint portion

Claims (6)

In a casting manipulator that projects the gripping member onto the target object and grips and collects the target object , one end of the linear flexible link for translational motion control wound around the feeding / winding mechanism is placed at the center of gravity of the gripping member. At the same time, the linear flexible link for translation / rotational motion control is coupled to the opposite end of the gripping member hand, and the linear flexible link for translational motion control and the linear flexible link for translation / rotational motion control. A casting manipulator characterized in that the translational motion and the rotational motion of the projected gripping member in the air can be controlled simultaneously or independently only by the translational force by the tension of the link .   2. The casting manipulator according to claim 1, wherein a bar is provided in a direction perpendicular to a plane through which the center of gravity moves, and a linear flexible link for translational motion control is coupled to both ends of the bar.   The slider is mounted on the gripping member on a straight line connecting the center of gravity of the gripping member and the hand of the gripping member, and the connecting portion between the linear flexible link and the gripping member is formed to be movable on the slider. The casting manipulator according to claim 1.   The projection operation of the gripping member is performed by applying a rotational motion to the gripping member by periodically changing the tension of the linear flexible link coupled to the gripping member or the position of the fulcrum. The casting manipulator according to any one of claims 1 to 3.   The casting manipulator according to any one of claims 1 to 4, wherein a position of a mechanism for feeding and winding the linear flexible link for translation / rotation motion control is variable.   The gripping member is mainly formed of a main body, an attacker corresponding to a palm portion, and a plurality of fingers, and the finger is closed when the attacker collides with a target object. The casting manipulator according to claim 1.

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