JPH02262984A - Rendering method for reference posture of robot - Google Patents

Abstract

PURPOSE:To render a reference position of a robot even at a user in extremely short time by providing a means for enabling the robot to meet the reference posture defined at the manufacturing stage of a maker's side. CONSTITUTION:A robot is correctly set for a reference posture, an absolute value encoder 6 is reset and positional data is initialized at the manufacturing stage of a maker's side. A marker searching operation is then performed, a motor 5 is driven in a specified direction, the movement amount (reference correction amount) between the reference position and marker signal is measured and stored in a memory 2. At the time when the reference position is rendered in a user's factory, the robot is first set for an approximate reference posture to perform a marker searching operation. A reference searching operation is then executed from the position stopped by the marker searching operation, the motor 5 is driven in the reverse direction to the marker searching operation and the reference posture is rendered by the marker signal detection and the movement of the reference correction amount part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for reproducing a reference posture in an industrial robot.

Conventional technologyIn robots with absolute position detection encoders,
In order to perform calculations related to position and orientation and perform trajectory control, etc., it is necessary to accurately correlate the relationship between the robot body orientation and encoder data.

On the robot manufacturer side, the robot body is accurately aligned with a reference posture during the manufacturing stage, and the encoder is reset there, or the encoder data in that posture is stored.

On the other hand, if the encoder data becomes abnormal at the user's site, it is necessary to take measures such as resetting the robot to align it with the reference posture at the site. In order to match this standard posture, manual operation is required to match the scales, marks, etc. that indicate the standard posture provided on each axis of the robot, which lacks accuracy.

Problems to be Solved by the Invention On the robot manufacturer side, the reference posture of the robot is accurately determined using a dedicated jig ψ equipment, etc., and is correlated with encoder data.

On the other hand, at the user's site, it is generally impossible to prepare jigs, equipment, etc. on site to adjust the robot to the reference posture due to placement problems, and it is extremely difficult to accurately align the robot to the reference posture. It has become.

As mentioned above, if this is done manually or visually, it will lack accuracy, and it will also be necessary to correct the data that has already been taught, which will take a lot of time to restore.

An object of the present invention is to accurately reproduce the reference posture of a robot even at the user's site using a simple method.

Means for Solving the Problem In order to achieve this object, the present invention rotates the drive motor in a specific direction from its reference posture on each axis of the robot, and encodes the encoder/marker signal generated during the operation and up to that point. The reference posture is accurately reproduced based on the movement amount data.

That is, the means rotates the drive motor in a specific direction from the robot reference posture, detects a marker signal generated during the operation, measures the amount of movement from the robot reference posture to the marker signal detection position, and stores it in a storage circuit. ,
means for rotating the drive motor in a direction opposite to the specific direction, detecting a marker signal generated during this operation, and moving the drive motor further from the marker signal detection position by the amount of movement stored in the storage circuit; It is equipped with

Operation In the present invention, the robot reference posture is reproduced as follows.

0) Special jigs are used at the manufacturing stage by robot manufacturers.

The robot is precisely aligned with the reference position using equipment, then moved in a specific direction, and stopped by detecting encoder/marker signals generated along the way. At the same time, the amount of movement to the marker signal detection position is measured and stored in the memory circuit by operator operation. (referred to as search operation 1).

(2) When reproducing the robot reference posture at the user's factory, the procedure is as follows. First, the robot is manually adjusted to approximately the reference posture (temporary reference posture), and the marker search operation is performed (no memorization operation is performed here). Next, the marker is moved from the stop position after the marker search operation in the opposite direction to the marker search operation, the encoder marker signal is detected, and the encoder marker signal is further moved from the detected position by the amount of movement stored in the memory circuit, and then stopped. (This series of operations in which a marker signal is detected, moves by the amount of movement stored from the detected position, and then stops is called a 1-base search operation.) The stopping position in this operation accurately reproduces the reference posture.

EXAMPLES Hereinafter, the present invention will be specifically explained based on examples. FIG. 1 shows an overview of the hardware configuration, and the entire system is controlled by a control circuit 1 centered on a microcomputer, and a motor 5 is driven via a motor driver 4. The absolute value encoder 6 is directly connected to the motor 6, and the position feedback signal and marker signal are sent to the control circuit 1.
has been returned to. It also includes a memory (storage circuit) 2 and an operation section 3.

Next, the operating procedure will be explained using FIG. FIG. 2(,) is a flowchart showing the steps at the manufacturing stage on the manufacturer's side, in which the robot is accurately adjusted to the reference posture, the absolute value encoder 6 is reset, and the position data is initialized. Then, a marker search operation is executed, and the motor 5 is driven in a specific direction to move the amount of movement between the reference posture and the marker signal (
This is called a reference correction amount) is measured and stored in the memory 2 in the next operation.

FIG. 2(b) shows the procedure for reproducing the reference position in the user's factory. First, the robot is aligned with the approximate reference posture and a marker search operation is performed. and,
A reference search operation is executed from the position where the marker search operation stopped, the hemotar is driven in the opposite direction to the marker search operation, the marker signal is detected, and the reference posture is reproduced by moving by the amount of reference correction.

The details of the marker search operation and the reference search operation will be explained using FIG. 3(&), Cb).

When the marker search operation is activated by an operator's instruction, the position data (Pl) of that position is first read from the encoder 6 and stored at -. Then, it outputs a command to drive the motor 6 in a specific direction (this is direction A) and waits for input of a marker signal. When the motor 6 rotates and a marker signal is input, the current position data (P2) is read and the motor 5 is temporarily stopped. Incidentally, in this embodiment, an operation of rotating the motor H is further added.

The movement amount (P2-Pl) is stored in the memory 2 as a reference correction amount according to an operator's instruction after the main marker search operation, and indicates the distance between the reference posture and the marker signal.

After the marker search operation is executed in accordance with the approximate reference posture, the reference search operation is activated. First, a motor drive command is outputted to move the motor 6 in a direction B opposite to the direction A, and the input of a marker signal is waited for. When the motor 6 rotates and a marker signal is input, the position data (P3) at that time is read from the encoder 6, and the motor 6 is temporarily stopped. Next, the reference correction amount stored in memory 2 is read out, and the amount of movement determined from the current stopped position and the marker signal generation position (P3) is corrected against the reference correction amount, and the amount of correction movement is calculated. calculate. Then, by moving by the corrected movement amount, it is possible to accurately return to the reference posture.

FIG. 4 illustrates the relationship between each position, direction, amount of movement, etc. in the present invention. As long as the motor 6 is not removed from the robot body, the positional relationship between the robot's posture and the marker signal will remain unchanged, and the positional relationship between the By accurately storing the distance (amount of movement) between the posture and the marker signal and reproducing it from the marker signal generation position, it is possible to accurately reproduce the reference posture.

Effects of the Invention As described above, according to the present invention, the robot reference posture can be easily and accurately reproduced. Previously, when encoder data was destroyed at a user's factory, the solution was to reset the encoder visually to match the reference posture without the proper equipment on site. This required work such as modifying the current data, and a large amount of time was spent on recovery. However, by using the present invention, it is possible to accurately match the reference posture defined at the manufacturing stage by the manufacturer, and recovery can be performed at the user's site in an extremely short time, which is highly effective.

[Brief explanation of drawings]

Fig. 1 is a block circuit diagram of an industrial robot showing an embodiment of the present invention, Fig. 2 is a flowchart showing the operating procedure of the industrial robot, and Fig. 3 shows the first operating element of the industrial robot. The flowchart, FIG. 4, is a time chart showing the relationship between each position, amount of movement, and direction of the industrial robot. 1... Control circuit (microcomputer), 2
...Memory, 3...Operation unit, 4...
...Motor driver, 6...Motor, e...
...Encoder. Name of agent: Patent attorney Shigetaka Awano and one other person Figure (α) <b> Figure (a,) <b)

Claims (1)

[Claims] In an industrial robot configured to control the movement of each robot's movable parts by a drive motor with an absolute position detection encoder equipped with a marker signal that generates one pulse per rotation, the means for rotating the drive motor in the direction and detecting the marker signal generated during the operation, measuring the amount of movement from the reference posture of the robot body to the marker signal detection position and storing it in a storage circuit; means for rotating the drive motor in a direction opposite to the above-mentioned direction, detecting a marker signal generated during this operation, and moving the marker signal further from the marker signal detection position by the amount of movement stored in the memory circuit. A method for reproducing robot reference postures.