JPS5969286A - Method of controlling cooperation of robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a robot cooperative control method for cooperatively operating a general-purpose robot and a special-purpose robot or a special-purpose peripheral device. This invention relates to a robot cooperative control method.

[Prior art]

When automating production using robots, it is not possible to automate all tasks using only general-purpose robots due to limitations such as the robot's work function, work area, and payload. Traditionally, these general-purpose robots and dedicated robots have been operated independently of each other.

For this reason, it became necessary for specialized robots to have the same functions as general-purpose robots, such as positioning functions and order memory functions, resulting in duplication of functions in double-mouthed bots, which had the disadvantage of making the robots expensive. .

[Purpose of the invention]

The present invention eliminates the drawbacks of the prior art described above, eliminates the duplication of functions between a general-purpose robot and a dedicated robot, and effectively utilizes a general-purpose robot, even if the functions of a dedicated robot are reduced. That is, the objective is to provide a robot cooperative control method that allows a desired task to be performed even when using an inexpensive dedicated robot.

[Summary of the invention]

The configuration of the robot cooperative control method according to the present invention is such that in the method of cooperatively controlling a general-purpose robot and a special-purpose robot, the positional deviation between the tip of the general-purpose robot and the tip of the special-purpose robot is determined. is connected via a position deviation detector capable of detecting the position deviation detector, and the target value of the acceleration of the general-purpose robot is corrected so that the second-order differential coefficient with respect to time of the signal from this position deviation detector becomes zero. This is what I did.

More details are as follows.

The functions that are important in general-purpose robots and specialized robots are positioning function and sequence memory function. Therefore, if the structure of the specialized robot is made to move freely in the direction of the force applied to its tip, the general-purpose robot can grasp the tip of the specialized robot and guide it, and the specialized robot does not need the above functions. becomes.

By the way, the problem with this is that when a general-purpose robot guides a specialized robot, the general-purpose robot has a large moment of inertia, and cannot generate the acceleration that the general-purpose robot can generate by moving alone. There is a risk that it will be judged as a failure and will stop.

Therefore, during guidance, it is necessary to lower the target value of the acceleration of the general-purpose robot. The degree of this reduction varies depending on the load on the dedicated robot, so it is not preferable to keep it constant. Therefore, we installed a position deviation detector that can detect the position deviation of both robots near the joint between the general-purpose robot and the dedicated robot. Since it corresponds to the difference in acceleration of the bot, so that this directness becomes zero,
In other words, by modifying the target acceleration of the general-purpose robot so that the general-purpose robot and the special-purpose robot move at the same speed, the general-purpose robot can move with this acceleration and guide the special-purpose robot. .

[Embodiments of the invention]

The robot cooperative control method of the present invention will be described below using an example in which it is applied to a screw tightening operation using a general-purpose robot and a special-purpose robot.

FIG. 1 is a perspective view showing a screw tightening robot used to implement a robot control method according to an embodiment of the present invention, and FIG. 2 shows the vicinity of the tip of the general-purpose robot in FIG. 1. FIG. 3 is a block diagram for explaining the cooperative control method of the robot according to FIG. 1.

In FIG. 1, reference numeral 1 denotes an articulated general-purpose robot with five degrees of freedom (a robot with five drive motors is generally referred to as a robot with five degrees of freedom), whose base 1a is fixed to the floor. uses the gripper 4 to grasp the screw tightening driver 2e of the dedicated robot 2, which will be described later, and tighten the screws 5a and 5bt 5 on a plane parallel to the floor.
This guides the robot to positions c+5dt 5e and 5f in sequence. Reference numeral 2 denotes a dedicated robot for screw tightening, which has a base 2a fixed to the floor and is articulated with two degrees of freedom. Position deviation detection 1S on wrist 1b
3 (details will be described later), and are connected via a gripper 4.

Describing the details of the dedicated robot 2, this dedicated robot 2
The arm 2b is rotatably attached to the Z axis with respect to the base 2a, and the arm 2c is rotatably attached to the Z axis with respect to the arm 2b. A driver holder 2f that holds the screw driver 2e is fixed. The connecting member 2d is attached to the arm 2C around the driver 2e so as to be rotatable around the Z3 axis.

Brakes (not shown) are installed at the positions of the Z1 axis and Z2 axis.
are attached, and when these brakes are applied, the driver holder 2f is fixed in that position, and when the brakes are released, when the general-purpose robot l applies force to the connecting member 2d, the driver holder 2f is fixed. can be moved freely in a plane parallel to the floor.

Details of the position deviation detector 3 will be explained using FIG. 2.

In FIG. 2, 3a is a pair of fixing plates, one of which is attached to the gripper 4 and the other is attached to the wrist 1b, facing each other, and 3b is a pair of fixing plates, which are attached facing each other between the fixing plates 3a. The leaf spring 3c is attached on the leaf spring 3b,
This strain gauge is capable of expressing the deflection of the leaf spring 3b in the y direction, that is, the positional deviation between the tip of the general-purpose robot 1 and the tip of the dedicated robot 2.

The cooperative control device 6 used to correct the target value of acceleration of the general-purpose robot 1 based on the output of the strain gauge 3c of the position deviation detector 3 will be described with reference to FIG. 3.
Calculate the second derivative with respect to time of the positional deviation manually input by the positional deviation detector 3, that is, the acceleration difference between the general-purpose robot 1 and the special-purpose robot 2, and adjust the acceleration of the general-purpose robot 1 so that this acceleration difference becomes zero. An acceleration corrector 8 for correcting a target value is a speed command calculator 9 for increasing the command speed of the general-purpose robot 1 from the corrected acceleration target value from the coordinate speed corrector 7 of the current position of the general-purpose robot 1. is an amplifier that amplifies the input from the speed command calculator 8, and 10 is an input amplifier from the amplifier 9, that is, a general-purpose robot l-
This is an actuator that moves 1.

The operation of the screw tightening robot configured as described above will be explained.

With the brake of the dedicated robot 2 released, the general-purpose robot 1 detects a position deviation detector 3 attached to its tip.
The connecting member 2d of the dedicated robot 2 is grasped via the gripper 4, and the dedicated robot 2 is guided within a plane parallel to the floor.

During this guidance process, the coordinate value Pt- of the target position of the guidance light,
When the movement speed target value vr up to Pt of and is sequentially given to the speed command calculator 8, the coordinate value P of the current position of the general-purpose robot 1, the coordinate value Pt of the target position, the movement speed target value Vf, the acceleration A command speed is calculated from the target value of acceleration from the corrector 7, and the actuator 10 is operated at this command speed.
moves the general-purpose robot 1, and the dedicated robot 2 is guided accordingly.

The acceleration corrector 7 corrects the target value of the acceleration of the general-purpose robot 1 by calculating the second-order differential coefficient with respect to time of the positional deviation based on the signal obtained from the positional deviation detector 3.

In this way, the difference in acceleration between the general-purpose robot 1 and the special-purpose robot 2 becomes zero, and the special-purpose robot 2'! il
- Since the robot is guided, the general-purpose robot 1 can guide the special-purpose robot 2 to the target position regardless of the moment of inertia of the special-purpose robot 2. After guiding and positioning the dedicated robot 2 to a predetermined target position, the brake is applied, the dedicated robot 2 is fixed at that position, and screw tightening is started. Since the reaction force at this time is applied to the dedicated robot 2, this robot can also perform screw tightening work that requires a torque greater than the rigidity of the general-purpose robot 1.

According to the embodiment described above, since the target value of the acceleration of the general-purpose robot 1 is corrected based on the signal of the position deviation detector 3, the general-purpose robot 1 can grasp the tip of the dedicated robot 2 and guide it, and the dedicated robot 2 has a positioning function.

This has the effect that the desired screw tightening work can be performed even without a sequence memory function.

In addition, Kuri Motomi explained about a general-purpose robot 1 and a dedicated robot 2 that perform screw tightening.
The present invention is not limited to screw tightening, but is widely applicable to, for example, automating shaft straightening work using one general-purpose robot and one dedicated robot.

〔Effect of the invention〕

As explained in detail above, according to the present invention, by eliminating the duplication of functions between a general-purpose robot and a dedicated robot and effectively utilizing the general-purpose robot If, even if the functions of the dedicated robot are reduced, Even if robots are used,
It is possible to provide a cooperative control method for robots that can perform a desired task.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a screw tightening robot used to implement a robot cooperative control method according to an embodiment of the present invention, and FIG. 2 is a perspective view of a robot near the tip of the general-purpose robot in FIG. FIG. 3, an enlarged perspective view showing details, is a block diagram for explaining the robot-cooperative control method according to FIG. 1. 1...General-purpose robot, 2...Special robot, 3...
・Position deviation detector, 6... Coordination control device, 7... Acceleration corrector. Agent $, +jr*1 car 'lj' 1. , ,” 1
) 1 (and 1 other person) Calyx 1 eyes 2 eyes 3 eyes

Claims (1)

[Claims] 1. In a method of cooperatively controlling a general-purpose robot and a special-purpose robot, position deviation detection can easily detect the positional deviation between the tip of the general-purpose robot and the special-purpose robot. The robot is connected via a vertical deviation detector, and the target value of the addition An of the general-purpose robot is corrected so that the second-order differential coefficient with respect to time of the signal from the vertical deviation detector becomes zero. To cooperative system both method.