JPH0929673A - Manipulator controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To markedly simplify labor required for calibration process by providing a camera in a handy position of a manipulator, calculating relative deviation from a picture image obtained from the camera and correcting a model stored in a model storing means according to the relative deviation by a model correcting means. SOLUTION: A handy camera 8 is provided in the handy part of an articular type manipulator. A photographed picture image is inputted to a relative position posture deviation calculation part 13 to process the coordinate comversion from the numerical value of camera coordinate system to the numerical value of manipulator coordinate system. Also, the deviation for the relative position posture to an object on a model from a manipulator action commanding part 9 is figured out. Then, in a model correcting part 16, models stored in a model storing part 15 are renewedly stored from actual position posture calculated in a calculation part 11 from respective detecting signals of angle detecting sensors 5-7 and the posture deviation, so that the calibration process of the actual absolute position posture and actual relative position posture and relative model position posture is executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manipulator control device for controlling a joint type manipulator which has a camera at its hand and receives the angular velocity of each joint as an input.

[0002]

2. Description of the Related Art A joint type manipulator generally has a shape similar to that of a human arm, and each joint has an actuator, an angle sensor and the like. Further, the visual system is roughly classified into a case where it is provided in a portion corresponding to the above-mentioned head and a case where it is provided in the hand of the manipulator. The configuration of the conventional manipulator device will be described below with reference to FIGS. 3 and 4.

FIG. 3 shows a manipulator in which the visual system 17 is provided at a position independent of the operation of the articulated manipulator 1, for example, when the articulated manipulator 1 is a human arm and a position corresponding to a human head. The structure of the control circuit is shown.

In the figure, the articulated manipulator 1 has actuators 2, 3, 4 and angle detection sensors 5, 6, 7 at each joint position. The model storage unit 15 stores models such as the position / orientation, dimensions, shape, and work procedure of the articulated manipulator 1 itself and the work target having such a configuration.
Based on the model stored in the model storage unit 15, the manipulator operation command unit 9 calculates the operation command Xr to the joint type manipulator 1, and the absolute position / orientation deviation calculation unit 12
On the other hand, the relative position and orientation with respect to the object on the model is sent to the relative position and orientation deviation calculation unit 13.

The absolute position / orientation deviation calculation unit 12 is composed of a subtraction circuit, and based on the operation command Xr from the manipulator operation command unit 9, the angle detection sensors 5, 6, 6 are described.
The actual absolute position / orientation X from the actual absolute position / orientation calculating unit 11 that collects the respective detection signals θ obtained in 7 to calculate the actual absolute position / orientation is subtracted, and the deviation ΔX is given to each joint angular velocity command unit 10.

Each joint angular velocity command unit 10 actually uses the error signal ΔX provided from the absolute position / orientation deviation calculation unit 12 to actually drive the actuator 2 of the joint type manipulator 1.
An angular velocity command for driving each of 3 and 4 is created and output.

However, the operating states of the actuators 2, 3 and 4 of the articulated manipulator 1 are not only directly detected by the angle detection sensors 5, 6 and 7, but also imaged by the visual system 17 described above. The image obtained by the system 17 is input to the relative position / orientation deviation calculation unit 13 and subjected to coordinate conversion processing from the numerical value of the camera coordinate system to the numerical value of the manipulator coordinate system.
Then, the deviation from the relative position and orientation with respect to the object on the model from the manipulator operation command unit 9 is calculated, and the model correction unit 1
Sent to 6.

The model correction unit 16 updates and stores the model stored in the model storage unit 15 according to the deviation from the relative position / orientation deviation calculation unit 13. The model storage unit 15 should be updated and stored. Then, the calibration process of the actual relative position and orientation and the model relative position and orientation is executed.

The calibration process using the visual system 17 is usually performed before the work operation by the articulated manipulator 1 with the articulated manipulator 1 in the home position posture so as not to obstruct the visual field of the visual system 17. After the calibration process is completed, the model updated and stored in the model storage unit 15 starts the actual work operation.

Further, FIG. 4 is a diagram in which a hand camera 8 is provided at the hand position of the articulated manipulator 1 in place of the visual system 17 of FIG. 3, and other circuit configurations and the like are shown in FIG. Since it is the same as the case described above, the same portions are denoted by the same reference numerals and the description thereof will be omitted.

However, unlike the case of the visual system 17, the image acquired by the hand camera 8 is usually not used for the calibration of the position of the articulated manipulator 1 and the position and orientation of the work object. And is usually used for final positioning correction and tracking of moving objects.

First, the case of performing the final positioning correction will be described. Based on the model data stored in the model storage unit 15, the manipulator operation command unit 9 causes the operation command Xr.
Is output.

For the motion command Xr output from the manipulator motion command unit 9, the actual absolute position / orientation calculation unit 11 finds from the read values θ of the angle detection sensors 5, 6, 7 of each joint of the articulated manipulator 1. Current actual absolute position and posture X
The deviation ΔX is obtained from the absolute position / orientation deviation calculation unit 12 from this, and either the obtained deviation ΔX or the relative position / orientation deviation obtained by the relative position / orientation deviation calculation unit 13 is switched and selected by the switching unit 14. The angular velocity commands given to the respective joint angular velocity command units 10 are outputted to the actuators 2, 3, 4 of the respective joints of the articulated manipulator 1.

However, when the final positioning correction is performed based on the image obtained by the hand camera 8, the switching unit 14 switches and selects the relative position / orientation deviation output from the relative position / orientation deviation calculating unit 13 as shown in FIG. Then, the connection control is performed so that the joint angular velocity command unit 10 is provided with the joint angular velocity command unit 10.

Further, when following a moving object as a work object based on the image obtained by the hand camera 8, the switching unit 1
4 is always switched and selected not to the relative position / posture deviation output side of the relative position / posture deviation calculation section 13 shown in FIG. 4 but to the absolute position / posture deviation ΔX side output from the absolute position / posture deviation calculation section 12. It can be realized by connecting by connecting.
In any of these cases, the model stored in the model storage unit 15 is not updated and the model correction unit 16 is not used.

[0016]

In the configuration shown in FIG. 3, since the visual system 17 for calibration is located at a position independent of the operation of the articulated manipulator 1, its visual field is obstructed. In order to prevent this from happening, it is usual to perform the calibration process with the articulated manipulator 1 in the home position.

Therefore, when it is attempted to carry out continuous work on a plurality of work objects, the calibration process is performed once during each work, or the position and orientation of each work object is determined before the work is started. It is necessary to start the work after performing the calibration process in advance, and in either case, it can be dealt with if the position and orientation of another work object moves due to some factor while performing one work. There is a problem that it disappears.

Further, as shown in FIG. 4, the articulated manipulator 1 is used for final positioning correction and tracking of a moving object.
If the camera 8 is provided at the hand of the
Originally, the tracking information cannot be reflected in the model. Therefore, when the absolute position / orientation deviation side is switched and selected by the switching unit 14 that switches and selects one of the absolute position / orientation deviation and the relative position / orientation deviation, the joint-type manipulator 1 returns to the initial target attitude, and after the calibration process or Since the final follow-up position information is completely lost, it becomes difficult to perform the repetitive work.

The present invention has been made in view of the above situation, and an object of the present invention is to significantly reduce the time and effort required for the calibration process even when performing continuous work on a plurality of work objects. Another object of the present invention is to provide a manipulator control device that is simplified and that can update a model even when correcting final positioning or following a moving object.

[0020]

According to the first aspect of the present invention,
According to the model storage means for storing the model indicating the position and orientation of the articulated manipulator equipped with the camera at the hand position as an input with the angular velocity of each joint, and the model stored in the model storage means The motion command means for outputting a motion command indicating the target hand position / posture to the manipulator, the angle detection means for detecting the angle of each joint of the manipulator, and the angle detection value of each joint obtained by this angle detection means First calculating means for obtaining the present position / orientation of the manipulator hand, absolute hand position / orientation of the manipulator obtained by the first calculating means, and hand target position / orientation of the action command output by the action commanding means The second calculating means for obtaining the deviation and the angular velocity command of each joint are given to the manipulator by the absolute deviation obtained by the second calculating means. The relative position and orientation with respect to the target object is obtained from the image obtained by the angular velocity commanding means and the camera provided at the hand position of the manipulator, and the hand target of the motion command output from this relative position and orientation and the motion commanding means. Third calculating means for calculating a relative deviation from the position and orientation;
A model for correcting the model indicating the position and orientation of the manipulator stored in the model storage means based on the relative deviation obtained by the third calculating means and the current hand position and orientation of the manipulator obtained by the first calculating means. And means.

With such a configuration, since the field of view of the camera provided at the hand position of the manipulator is not obstructed by the manipulator itself, it can be obtained by the camera even at the start or during the operation of the manipulator. The calibration process can be executed by correcting the model stored in the model storage unit by the model correction unit based on the relative deviation obtained from the image by the third calculation unit.

According to a second aspect of the invention, in the invention of the first aspect, one of the absolute deviation obtained by the second calculating means and the relative deviation obtained by the third calculating means is switched. A switching means for selecting and supplying the angular velocity command means is further provided.

With such a configuration, the switching means selects and switches the relative deviation obtained by the third calculating means and supplies the relative deviation to the angular velocity commanding means, so that the third image is obtained from the image obtained by the camera. It is possible to store the final position and orientation of the work object by reflecting the relative deviation obtained by the calculation means in the model, and it is possible to realize the final positioning correction or the tracking of the moving object.

[0024]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram in which, instead of the visual system 17 of FIG. 3, a hand camera 8 is provided at the hand position of the articulated manipulator 1, and other circuit configurations are almost the same as those shown in FIG. Therefore, the same parts are designated by the same reference numerals and the description thereof will be omitted.

Thus, the image obtained by the hand camera 8 is input to the relative position / orientation deviation calculating unit 13 and subjected to coordinate conversion processing from the numerical value of the camera coordinate system to the numerical value of the manipulator coordinate system. The calculation unit 13 calculates the deviation from the relative position and orientation of the object on the model from the manipulator operation command unit 9, and sends the deviation to the model correction unit 16.

The model correction unit 16 also receives from the real absolute position / orientation calculation unit 11 which collects the respective detection signals θ obtained by the angle detection sensors 5, 6, 7 of the articulated manipulator 1 to calculate the real absolute position / orientation. The actual absolute position / orientation X of is input.

The model correction unit 16 updates and stores the model stored in the model storage unit 15 according to these inputs. By updating and storing the model storage unit 15, the actual absolute position / orientation and the actual relative position / orientation are obtained. And the model relative position and orientation are calibrated.

In the above-described structure, the hand camera 8 is provided at the hand position of the articulated manipulator 1, and the visual field of the image obtained by the hand camera 8 is not obstructed by the manipulator itself. Even when the manipulator 1 is not in the home position and the work is started or during the work, the model correction unit 16 stores the model in accordance with the relative deviation obtained by the relative position / orientation deviation calculation unit 13 from the image obtained by the camera. The calibration process can be executed by modifying the model stored in the unit 15.

Therefore, even when continuous work is performed on a plurality of work objects, the calibration process can be performed without returning the articulated manipulator 1 to the home position one by one, and the labor required for the calibration is greatly increased. It is possible to simplify, and it is possible to avoid the situation where the work objects unexpectedly move and become unable to cope after the position and orientation of the plurality of work objects are collectively calibrated. .

In addition to the configuration of FIG. 1, FIG. 2 shows the absolute position / posture deviation ΔX output by the absolute position / posture deviation calculator 12 and the relative position / posture deviation output by the relative position / posture deviation calculator 13. A switching unit 14 similar to that shown in FIG. 4 is provided, which switches and selects one of them and supplies it to each of the joint angular velocity command units 10. This switching unit 14 is connected to the relative position / orientation deviation calculating unit 13 side in FIG.

In the above-described structure, when the final positioning correction or the tracking of the moving object is performed, the switching unit 14 is connected to the relative position / orientation deviation calculating unit 13 side as shown in FIG. It is assumed that the relative position / orientation deviation output from the position / orientation deviation calculation unit 13 is switched and selected and supplied to each joint angular velocity command unit 10.

At this time, the relative position / orientation deviation output from the relative position / orientation deviation calculation unit 13 is also sent to the model correction unit 16 and used for updating the model stored in the model storage unit 15. As a result, the actual position and orientation of the work target after the correction of the final positioning and the tracking of the moving object are stored in the model storage unit 15.

In this way, by storing the actual position and orientation of the work object after the correction of the final positioning and the tracking of the moving object in the model storage unit 15, after performing other work. Even if it becomes necessary to access again, it is possible to easily deal with it only by position control, and it is possible to significantly reduce the time and effort required for the calibration process, which is suitable for the same repetitive work.

[0034]

As described above, according to the present invention, even when performing a continuous work on a plurality of work objects, the labor required for the calibration process is greatly simplified, and the final positioning correction or It is possible to provide a manipulator control device capable of updating a model even when following a moving object.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a circuit configuration according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating another circuit configuration according to the same embodiment.

FIG. 3 is a block diagram illustrating a circuit configuration of a conventional manipulator control device.

FIG. 4 is a block diagram illustrating a circuit configuration of a conventional manipulator control device.

[Explanation of Codes] 1 ... Joint type manipulator 2, 3, 4 ... Actuator 5, 6, 7 ... Angle detection sensor 8 ... Hand camera 9 ... Manipulator operation command section 10 ... Joint angular velocity command section 11 ... Real absolute position / orientation calculation Part 12 ... Absolute position / orientation deviation calculation unit 13 ... Relative position / orientation deviation calculation unit 14 ... Switching unit 15 ... Model storage unit 16 ... Model correction unit 17 ... Visual system X ... Real absolute position / orientation Xr ... Motion command ΔX ... Deviation

Claims (2)

[Claims] 1. A model storage unit for storing a model indicating the position and orientation of a joint type manipulator having a camera at a hand position as an input, the angular velocity of each joint being input, and the model storage unit. According to the model described above, a motion command means for outputting a motion command indicating the target hand position / posture to the manipulator, an angle detection means for detecting the angle of each joint of the manipulator, and an angle detection means for each joint obtained by this angle detection means. First calculation means for obtaining the current position / orientation of the manipulator hand from the detected angle value, and the hand current position / orientation of the manipulator obtained by the first calculation means and the hand target of the motion command output by the motion command means. Second calculating means for obtaining an absolute deviation from the position and orientation, and each of the functions of the manipulator by the absolute deviation obtained by the second calculating means. The angular velocity command means for sending the angular velocity command and the relative position and orientation with respect to the object are obtained from the image obtained by the camera provided at the hand position of the manipulator, and the relative position and orientation and the operation output from the operation commanding means. Based on the third calculation means for calculating the relative deviation of the command from the target hand position / posture, the relative deviation obtained by the third calculation means, and the current hand position / posture of the manipulator obtained by the first calculation means. And a model means for modifying a model indicating the position and orientation of the manipulator stored in the model storage means. 2. A switching means for switching and selecting one of the absolute deviation obtained by the second calculating means and the relative deviation obtained by the third calculating means and providing it to the angular velocity commanding means. The manipulator control device according to claim 1, wherein