JPH1199488A - Motion control method of grinding tool on robot, and data origination method for motion control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motion control method of a grinding tool and a data origination method for motion control on a robot to eliminate mechanical impact etc., generated in accordance with a speed change during positional movement of the grinding tool by copying control motion. SOLUTION: A track data 102 for positional movement control and a track data 103 for attitude maintenance control are separately and independently provided, and motion of a grinding tool is controlled by using each of these track data 102, 103 under a motion control method of a robot to carry out positional movement control of the grinding tool by the track data 102 set by copying a shape of a molded surface of a work and attitude maintenance control of a head end part for grinding of the grinding tool.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for controlling the operation of a grinding tool in a robot and a method for creating operation control data. Specifically, using a grinding tool, for example,
For robots that perform scanning control operations corresponding to the surface to be molded for grinding and forming operations such as deburring, grindering, polishing, etc., the work posture of the grinding tool with respect to the surface to be molded can be controlled regardless of the movement operation To an improved operation control method and a method of creating operation control data.

[0002]

2. Description of the Related Art In general, in a robot that performs this type of scanning control operation, a grinding tool such as a grinding wheel or a cutting tool of each type is used in a manner in which the robot operation unit is fixed and gripped.
The operation mode of the grinding tool based on the trajectory data for the profiling control includes moving the position of the tool in accordance with the shape of the surface to be formed of the work to be worked, and more specifically, the tip (grinding) for directly grinding the tool. Control (driving control of the position-moving servomotor) for the position movement of the cutting tip) and the characteristics of the shape of the tip for grinding, such as the shape of the grinding wheel surface if the corresponding grinding tool is a grinding wheel. If it is a cutting tool, it is necessary to specify the characteristics such as the shape of the cutting edge and the orientation such as the direction and angle of the tool during position movement with respect to the molding surface. Servo control (drive control of the attitude maintaining servomotor).

[0003] By the way, trajectory data for instructing operation control to a grinding tool, that is, tracing operation control data in a broad sense, usually includes a completed molded shape assumed after a molding operation, which is assumed to be a molding surface. Position data for moving the tool following the movement, and posture data for always maintaining the posture of the tool in a proper direction and angle toward the surface to be formed, in accordance with the movement, always the tool, and eventually the grinding tip of the tool. However, in the conventional scanning control operation, as described below, the position data for the former position movement is mainly used, and the posture data for maintaining the posture of the latter is basically based on the position data. This is set by following the movement.

FIG. 3 is a flow chart showing a process of creating copying operation control data for regulating the operation of a conventional grinding tool.

Referring to FIG. 3, in the conventional case, in the trajectory data generating section A ', respective target values 201 for position movement and attitude maintenance adapted to the operation of the grinding tool are calculated in advance. From among the calculated target values, first, the position data is created by using the position movement target value 201a, and the trajectory data 202 of the position movement is created (step S-21).

Subsequently, the data distribution processing section B 'calculates a servo command value 203 for the position movement based on the created trajectory data 202 for the position movement (step S-22), and then calculates the servo command value 203 for the position servo control command. The processing is performed as step 204 (step S-23). Further, based on the servo command value 203 of the position movement, the target value 20
1b, the posture data is calculated (in other words, the posture maintenance servo command value 205 is calculated (step S-24), and this is processed as the posture servo control command 206 (step S24).
−25).

That is, the conventional copying operation control data first includes, as described above, position data for controlling the position movement of the grinding tool (orbit data for performing the position movement and corresponding to the position servo control command 204). After independently prepared, the attitude data for controlling the maintenance of the attitude of the grinding tip (orbit data for maintaining the attitude and corresponding to the control command 206 of the attitude servo) is the movement of the position movement provided by the position data. It is created on the basis of following the entire area.

[0008]

However, in the servo control of the copying operation using the position data (204) and the posture data (206) for the above-mentioned conventional grinding tool, the position data (204) initially set. Since the attitude data (206) is obtained on the basis of the above, the attitude maintenance such as the direction and angle of the tool during the position movement with respect to the molding surface is always always appropriate regardless of the position movement. Although it should be servo-controlled by the value, this is only governed by the movement of the position, and consequently, the posture of the tool itself with respect to the change of the position accompanying the movement of the grinding tool. , In particular, the attitude change of the grinding tip does not always accurately adapt, and there is a problem that independent operation control for maintaining the attitude cannot be performed.

The problem of the conventional copying operation control will be described in more detail.

FIG. 1 is an explanatory view schematically showing a general and typical example of a copying control operation of a grinding tool in a robot.

In FIG. 1, reference numeral 11 denotes a work as a work object, and reference numeral 12 denotes a work surface (formed surface) to be formed on the surface of the work 11 or the like. Reference numeral 21 denotes a grinding tool mainly fixedly gripped by an operating unit of a robot (not shown) to grind the surface 12 to be formed. In this example, an electric grinding wheel (hereinafter, referred to as an electric grinding wheel) including a rotary drive motor 21a. In the specific description of, the grinding tool is limited to a grinding wheel), and reference numeral 22 denotes a grinding wheel surface as an integrated grinding tip of the grinding wheel 21. Here, the grindstone surface 22 as a grinding tip substantially corresponds to a grindstone edge portion for grinding, and in the grinding operation, as is well known, a required distance from the molding surface 12 is required. Abutting force.

In this case, regarding the molding surface 12,
A first forming surface 12a having a linear shape on the approach side from the working positions P1 to P2, a second forming surface 12b having a concentric arc shape of an intermediate transition portion from the working positions P2 to P3, and a working position It is assumed that each of the extraction surfaces P3 and P4 on the extraction side and the third molding surface 12c, which has a straight shape again, has a shape that is sequentially continuous. Therefore, the working position P2 corresponds to a transition point from the first molding surface 12a to the second molding surface 12b, and the working position P3 corresponds to the third molding surface from the second molding surface 12b. This corresponds to a transition point to the surface 12c.

On the other hand, with respect to the grinding wheel 21, the working position P1 to P4 is controlled by a position moving servomotor (not shown again) which is driven and controlled by the position data servo control command 204 in the fixed gripping state.
Is continuously moved at a constant speed S in accordance with the shape of each of the molding surfaces 12a to 12c up to this point, and the grindstone surface 22 is driven and controlled by a servo control command 206 of the position data. By changing the gripping form of the grinding wheel 21 and, consequently, the gripping direction and the gripping angle, the respective molding surfaces 12
The posture is always determined to be appropriate in response to the shape change for each of a, 12b, and 12c.

Here, the conventional position data (204)
Grinding wheel 21 of FIG. 1 using the position data (206)
Study of position movement and attitude maintenance for grinding operation in the laboratory.

The grinding wheel 21 and its grinding wheel surface 22
Moves at a predetermined speed S through each of the working positions P1 → P2 → P3 → P4 of the molding surface 12 set on the work 11, and if attention is paid only to the driving speed of the position moving servomotor, the linear shape is First molded surface 12
a forming surface 12 having a concentric arc shape from the terminal side of
When shifting to the starting end side of b, a speed change occurs due to the gradual deceleration S-ΔS of the moving speed, and a third straight line shape is again formed from the end side of the arc-shaped second molded surface 12b. When shifting the molding surface 12c to the starting end side,
It is apparent that a speed change is caused by the gentle acceleration S + ΔS of the moving speed for returning the deceleration S−ΔS equivalent to the predetermined speed S again.

With respect to the attitude maintaining servomotor for controlling the attitude of the grinding wheel 21, the first and third molding surfaces 12a (P1 → P2) and 12c (P3 → P4)
Since the position movement within the robot is linearly performed by the speed S, there is no change in the posture maintaining state. Therefore, the servo control operation for maintaining the posture is not performed, and the operation is stopped. In the forming surface 12b (P2 → P3), at the time when the work position P2 at which the movement is shifted from the linear movement to the curved movement is reached, a change in the movement speed at that position (in this case, a gentle deceleration S− (S), an instantaneous posture servo control start operation at a speed commensurate with (S) is required. Similarly, at the work position P3 where the shift from the curved movement to the linear movement is performed, the change in the position movement speed ( In this case, an instantaneous attitude servo control end operation at a speed commensurate with gentle acceleration S + ΔS) is required.

Therefore, in the conventional operation control for the grinding wheel 21, the transition point P2 in the posture maintaining servomotor is used.
The mechanical shock that occurs at the time of the sudden start at the start of the control operation at the time of the control operation and at the time of the sudden stop at the end of the control operation at the transition point P3 causes undesirable machining of the corresponding portion of the molding surface 12. There has been a problem that there is a fear that the wound may be given.

In view of the above-mentioned conventional disadvantages, an object of the present invention is to provide
Provided are a method of controlling the operation of a grinding tool in a robot and a method of creating operation control data, which can effectively eliminate mechanical shocks and the like caused by a change in speed during movement of the position of the grinding tool due to a copying control operation. It is in.

[0019]

In order to achieve the above object, in the present invention, position data for controlling the position movement of a grinding tool and posture data for controlling the maintenance of the posture of the tip for grinding are separately classified. By setting, the attitude data, which was totally dependent on the position data, is separated from the position data and made independent independently, and the surface to be formed is not restricted at all by the speed change of the grinding tool during the servo position movement. The attitude of the tip for grinding with respect to the direction, angle and the like is always kept properly.

That is, the method for controlling the operation of a grinding tool in a robot according to the present invention is a method for controlling the movement of the position of a grinding tool based on trajectory data set in accordance with the shape of a surface to be formed of a work as a work object, In the operation control method of a robot for performing posture maintaining control of a tip for grinding, trajectory data for the position movement control and trajectory data for the posture maintaining control are provided independently of each other. Is used to control the operation of the grinding tool.

In this operation control method, the trajectory data for the position movement control with respect to the grinding tool and the trajectory data for the attitude maintaining control are provided independently of each other. At the time of forming, the posture such as the direction and angle of the tip for grinding with respect to the portion to be formed can always be appropriately maintained without being restricted by the movement of the grinding tool.

Further, the method for preparing operation control data of a grinding tool in a robot according to the present invention is characterized in that a position movement control of the grinding tool is performed by using trajectory data set according to a shape of a forming surface of a work as a work object. And a method of creating operation control data of a robot that performs attitude maintaining control of a grinding tip of a grinding tool, wherein calculating target values for position movement and attitude maintenance adapted to a forming operation by the grinding tool. A step of independently producing trajectory data of position movement using the target value of position movement and trajectory data of posture maintenance using the target value of posture maintenance among the calculated target values. And at least

In this method of preparing operation control data, after calculating respective target values for position movement and posture maintenance with respect to the grinding tool, the trajectory data for position movement control is calculated based on the target values for position movement, and the trajectory data for posture maintenance is calculated. Since the trajectory data of the attitude maintaining control is obtained individually according to the target value, it is possible to independently create each trajectory data.

Further, the method for creating operation control data of a grinding tool in another robot according to the present invention is directed to a method for moving the position of a grinding tool based on trajectory data set in accordance with the shape of a surface to be formed of a work as a work object. In a method of creating data for operation control of a robot that performs servo control and a posture maintaining servo control of a grinding tip of a grinding tool, each target value for position movement and posture maintenance adapted to a forming operation by the grinding tool is set. The step of calculating and, among the calculated target values, the trajectory data of the position movement using the target value of the position movement, and the trajectory data of the posture maintenance using the target value of the posture maintenance, respectively. And calculating a servo command value of the position movement based on the created trajectory data of the position movement and controlling the position servo control value. A procedure of processing as a command, based on the trajectory data of the created position maintaining calculates a servo command value for position maintaining, characterized in that it comprises a step of treating it as a control instruction attitude servo.

In this method of creating operation control data, after calculating respective target values for position movement and posture maintenance with respect to the grinding tool, the trajectory data for position movement control is calculated based on the target values for position movement, and the posture maintenance data is used. Since the trajectory data of the attitude maintenance control is obtained individually according to the target value, it is possible to create each trajectory data independently for each trajectory data.
A position servo control command can be obtained from the trajectory data of the position movement control, and a posture servo control command can be obtained from the trajectory data of the posture maintenance control.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIG.

According to the present invention, as described above, the copying operation control data is constituted by the trajectory data of the position movement and the trajectory data of the attitude maintenance respectively created, and the grinding tool fixed and held by the robot. Servo drive is controlled under a free attitude that is not constrained by the control of the position movement. The purpose of the present invention is to always maintain the posture of the tip portion with respect to the workpiece forming surface properly and to effectively avoid unexpected situations such as mechanical impacts due to changes in the moving speed.

FIG. 2 is a flowchart corresponding to FIG. 3 and shows a process of creating copying operation control data for regulating the operation of the grinding tool to which the embodiment of the present invention is applied.

Referring to FIG. 2, in the copying operation control data according to the present embodiment, target values for position movement and attitude maintenance suitable for the operation of the grinding tool are calculated in advance, and the calculated target values are calculated. From the position movement trajectory data and the posture maintenance trajectory data, respectively, and, using the position movement trajectory data, the target position servo control command is similarly used. The purpose of the present invention is to separately create the desired attitude servo control commands. In the former position servo control commands, the position of the grinding tip 22 of the grinding wheel 21 as a grinding tool is servo-controlled, and at the same time, the attitude is controlled. The servo control command servo-controls the maintenance of the posture of the grinding tip 22 during the position movement.

That is, as a result, by separately obtaining the trajectory data of the position movement and the trajectory data of the attitude maintenance,
Grinding tip 2 in grinding wheel 21 for grinding
With regard to the second servo drive, the posture maintaining control is performed in a free state without any restriction by the control of the position movement.

The creation of the copying operation control data in this embodiment will be described in more detail. In the trajectory data generation unit A, the trajectory of the position movement as the position data is first determined by using one of the target values 101a for the position movement and the posture maintenance calculated above, using the target value 101a of the one position movement. The data 102 is created (step S-11), and the trajectory data 103 of the attitude maintenance as the attitude data is independently created using the other attitude maintenance target value 101b (step S-12). I do.

Subsequently, the data distribution processing unit B calculates a servo command value 104 for position movement based on the created position movement trajectory data 102 (step S-13).
Then, this is independently processed as a position servo control command 105 (step S-14). Similarly, the attitude maintenance servo command value 106 is calculated based on the created attitude maintenance trajectory data 103. After performing (Step S-15), this is independently processed as a posture servo control command 107 (Step S-16).

That is, in the case of the present embodiment, the servo command value 203 of the position movement is different from the conventional case described above.
The servo command value 205 for maintaining the posture is calculated from the target value 201b for maintaining the posture, and is not processed as the control command 206 for the posture servo. Control command 107
And also obtain each independently.

Therefore, the trajectory data 102 of the position movement and the trajectory data 1 of the attitude maintenance, which are individually created as described above,
03: Copying control operation of the grinding wheel 21 using or
According to the scanning control operation of the tip 22 for tool grinding by the control command 105 of the position servo and the control command 107 of the posture servo, each operation of the position movement and the posture maintenance is performed independently. As described above, it is possible to easily and effectively solve the respective problems of the conventional method.

Here, a description will be given with reference to FIG. At the time of the transition accompanying the position movement control by the control command 105 of the position servo of the grinding wheel 21 from the end side of the linearly shaped first molding surface 12a to the start end side of the concentric arc-shaped second molding surface 12b. Therefore, a speed change due to the gradual deceleration S-ΔS occurs in the moving speed of the grinding tip 22 at the transition point P2, and up to this point, the attitude maintaining control of the grinding tip 22 is not performed at all. There is no movement and it is kept almost stationary.

In this state, the grinding tip 22 moves to the transition point P
When the speed reaches S2 and the speed is gradually reduced S-ΔS following the second molding surface 12b, the attitude servo control command 1 set in accordance with the shape of the molding surface 12
07, the attitude of the grinding tip 22 also starts to change gradually following the second molded surface 12b, and thus the attitude maintenance control smoothly follows the position movement control at that time. Therefore, the occurrence of mechanical shock accompanying the activation of the instantaneous attitude change in response to the speed change as in the conventional case is eliminated, and it is not preferable for the corresponding portion of the molding surface 12 (near the transition point P2). There is no fear of giving processing scratches.

The contour control operation for maintaining the posture in accordance with the speed change of the position movement is performed by re-shaping the linearly formed third molding surface 12c from the end side of the arc-shaped second molding surface 12b. Is exactly the same with respect to the speed change due to the slow acceleration of the moving speed S + ΔS at the time of shifting to the start end side. In this case, the same operation and effect can be obtained.

[0038]

As described in detail above, according to the operation control method of the present invention, the trajectory data for the position movement control with respect to the grinding tool and the trajectory data for the attitude maintaining control are provided independently of each other. Since the operation of the grinding tool is controlled using the respective trajectory data, the grinding tip of the tool with respect to the workpiece is not restricted at all by the movement of the grinding tool when the workpiece is ground. It can always maintain the orientation such as the direction and angle of the part properly, and eliminates the mechanical shock generated on the grinding wheel surface due to the instantaneous posture change in response to the change in the moving speed of the grinding tool, and It can effectively eliminate the fear of processing scratches on the molding surface,
Moreover, there is an advantage that the method itself is extremely simple and can be easily implemented.

According to the method of preparing operation control data of the present invention, each target value for position movement and attitude maintenance with respect to the grinding tool is calculated, and the trajectory data for position movement control is calculated based on the target value for position movement. Since the trajectory data of the attitude maintaining control is obtained individually according to the target value of the maintenance, each of these trajectory data can be easily and independently created.

After calculating the respective target values for the position movement and the attitude maintenance with respect to the grinding tool, the trajectory data of the position movement control is calculated by the target value of the position movement, and the trajectory of the attitude maintenance control is calculated by the target value of the attitude maintenance. Since the data is obtained separately, it is possible to create each trajectory data independently.At the same time, the position servo control command is obtained from the trajectory data of the position movement control, and the attitude servo control is obtained from the trajectory data of the attitude maintenance control. Can be individually obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a general and typical example of a copying control operation of a grinding tool in a robot.

FIG. 2 is a flowchart showing a process of generating copying operation control data for regulating the operation of a tool to which an embodiment of the present invention is applied.

FIG. 3 is a flow chart showing a process of creating copying operation control data for restricting the operation of a conventional tool.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 work (work target) 12 molded surface (work surface) 12a first molded surface 12b second molded surface 12c third molded surface 21 grinding wheel (mainly grinding tool) 21a rotating motor 22 Grinding stone surface (tip for grinding) P1 to P2 Working position (corresponding to first molding surface) P2 to P3 Working position (corresponding to second molding surface) P3 to P4 Working position (third molding surface P2, P3 Transition point A Trajectory data generation unit B Data distribution processing unit 101 Target values for position movement and posture maintenance 101a Target value for position movement 101b Target value for posture maintenance 102 Trajectory data for position movement 103 Posture Trajectory data for maintenance 104 Servo command value for position movement 105 Position servo control command 106 Servo command value for attitude maintenance 107 Control command for attitude servo

Claims (3)

[Claims] An operation control of a robot for controlling the position and movement of a grinding tool based on trajectory data set in accordance with the shape of a surface to be formed of a work as a work object and maintaining the attitude of a grinding tip of the grinding tool. In the method, the trajectory data for the position movement control and the trajectory data for the attitude maintaining control are separately provided independently, and the operation of the grinding tool is controlled using the respective trajectory data. Operation control method of grinding tool in robot. 2. An operation control of a robot for performing position control of a grinding tool based on trajectory data set in accordance with a shape of a surface to be formed of a work as a work object and control for maintaining a posture of a grinding tip of the grinding tool. In the method for creating data, a process of calculating respective target values for position movement and posture maintenance adapted to the forming operation by the grinding tool, and, among the calculated target values, a target value of position movement. Using the position movement trajectory data and the attitude maintenance target values to independently generate the attitude maintenance trajectory data. How to create 3. A robot that performs servo control of the position of a grinding tool based on trajectory data set according to the shape of a surface to be formed of a workpiece as a work object and servo control for maintaining the attitude of the grinding tip of the grinding tool. In the method for creating operation control data, a step of calculating respective target values for position movement and posture maintenance adapted to the forming operation by the grinding tool; and, among the calculated target values, a target of position movement. Trajectory data of the position movement using the values, and a step of independently creating the trajectory data of the posture maintenance using the target value of the posture maintenance, respectively. Calculating a servo command value for the position movement based on the position command, and processing this as a control command for the position servo; and a posture based on the created posture maintaining trajectory data. Calculating a maintenance servo command value and processing the same as a posture servo control command. A method for generating operation control data of a grinding tool in a robot, comprising: