JP2625836B2 - Robot control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot control device and a robot control method using the control device.

SUMMARY OF THE INVENTION The present invention relates to a vertical lift command amount (hereinafter referred to as "vertical lift amount") in a robot controller for performing a portal-type composite operation in which a raising operation, a horizontal movement operation, and a lowering operation of a hand effector are partially overlapped. ) And a vertical descent command amount (hereinafter, referred to as a vertical descent amount) to define the portal-type combined operation, thereby enabling the robot to perform insertion and withdrawal operations from above with respect to the position of the insertion / extraction point and its depth. Irrespective of the above, it is possible to accurately perform only by teaching the final positioning point and designating the vertical movement amount.

[Prior art] The portal-type composite operation in which the ascending operation, the horizontal movement operation, and the descending operation are partially overlapped is mainly used for industrial assembly robots, and this function is independently developed by a robot maker. Although there is no known method that is widely and generally used, as shown in FIG. 7, the ratio to the total vertical ascending amount at which horizontal movement is started with monitoring means for ascending movement and horizontal movement and ascending and descending are shown. It is easy to use a method in which the ratio to the total horizontal movement amount at which the movement is started is specified in advance, or a method in which the user can change the operation shape stepwise without specifying the details, and these methods are used. Seems to be.

[Problems to be Solved by the Invention] However, in these methods, since the amount of vertical descent at the time of the descent operation is unknown, when it is desired to perform the insertion operation or the extraction operation accurately, a gate-type operation without overlapping operation is performed. Only the ascending motion and the horizontal motion have to be partly overlapped with the portal motion, resulting in a long working time for the robot. Further, when it is desired to shorten the working time, it is necessary to determine not only the final positioning point but also the trajectory to the operating point many times when teaching the operating point to the robot.

Therefore, in the present invention, the operation time of the robot is as short and accurate as possible and can be easily taught.

[Means for Solving the Problems] The robot controller of the present invention has a drive shaft for moving the position of the hand effector in the vertical direction and a drive shaft for operating the hand effector in the horizontal direction. A gate-type composite operation in which the moving operation and the lowering operation are partially overlapped with each other, wherein (a) means for monitoring the actual amount of rise of the hand effector; and (b) means for monitoring the actual amount of rise. Means for starting the horizontal movement operation by overlapping with the ascending operation when it is determined that the ascending amount has reached the designated vertical ascending command amount; and (c) descending capable of descending by the designated vertical descending command amount. Means for predicting the operation start point from a function of the vertical descent command amount and time; (d) horizontal movement time monitoring means for monitoring the horizontal movement time; and (e) information from the horizontal movement time monitoring means.
Means for starting the lowering operation by overlapping the horizontal movement operation at the lowering operation start point so as to lower the hand effector by the vertical lowering command amount.

In addition, it is desirable to prescribe the vertical ascending command amount and the vertical descending command amount in advance to define the portal-type composite operation.

[Operation] According to the above configuration of the present invention, at the time of executing the composite operation, a descent operation start point capable of descending vertically by a vertical descent amount specified from a function of the descent amount and time is determined during the horizontal movement operation time. You get only one. When the hand effector is rising, the rising amount monitoring means determines whether or not it has risen by more than a specified vertical rising amount. When the vertical moving amount reaches the specified vertical rising amount, the horizontal movement operation is started over the rising. When the hand effector is performing the horizontal movement operation, it is determined by the horizontal movement time monitoring means whether or not it is before the lowering operation start point, and if the lowering operation start point is reached and the ascending operation has been completed, the horizontal moving operation is performed. The lowering operation is started again.

Therefore, according to the present invention, only the teaching of the final positioning point may be performed by previously designating the depth of the insertion operation and the extraction operation from above as the vertical ascending amount and the vertical ascending amount.

[Embodiment] FIG. 1 shows a robot having two drive shafts for horizontal movement and one drive shaft for vertical movement to be controlled by a robot control apparatus according to the present invention, and its control. It is a block diagram of the whole device. In the figure, 101 is an input / output circuit of a control device, 102 is a storage device for storing a specified amount of vertical rise or vertical fall or storing a program, 103 is a computer for executing a program or performing various calculations, 104 Is a servo circuit that drives each arm of the robot in accordance with a command from 103.

FIG. 2 shows the control unit of FIG. 1 in more detail. In the figure, 201, 204, 207 are encoders attached to each drive shaft, a counter that counts a pulse train sent from a rotation angle detection device such as a resolver, that is, a counter that indicates the actual arm position, 202, 205, 208
Is a D / A that receives the speed command to operate each arm
The converters 203, 206, and 209 are servo drive circuits that operate each arm based on a given speed command. calculator
At 210, a speed command is created from the counters of 201, 204, and 207 and the control position of each arm in the storage device 211 at given minute intervals, and the speed commands are given to the D / A converters of 202, 205, and 208. To control each arm. The position of each arm is calculated in synchronization with the control at regular time intervals, and the storage device 21
The arm is operated by changing the control position of each arm in 1.

FIG. 3 is a diagram showing the trajectory of the hand effector of the robot according to the present invention. In the figure, reference numerals 301 and 302 denote vertical ascending amounts and vertical descending amounts, respectively. The user inputs these values in advance from the input / output circuit of FIG.

FIG. 4 shows the vertical ascending axis / horizontal moving axis / vertical descending axis of the composite operation according to the present invention, with the vertical axis representing speed and the horizontal axis representing time. In the figure, the hatched portions 401 and 402 indicate the vertical rising amount and the vertical falling amount, respectively. In executing the composite operation, a descent start point is first calculated from the specified vertical descent amount. This is obtained as the time from the start of horizontal movement to the start of descent by solving the function of descent amount and time. This calculation depends on the acceleration / deceleration curve used, and is not limited. In the present embodiment, the calculation of the descent start point when the vertical axis is operated by the uniform acceleration curve will be described. The constant acceleration curve is divided into three sections: an acceleration section, a constant velocity section, and a deceleration section. Each movement amount is S ₁ ,
Let S ₂ , S ₃ , and the movement time be t ₁ , t ₂ , t ₃ , the movement amount S and the speed V and acceleration A specified by the performance of the operation axis of the robot or the user's designation, S = S ₁ + S ₂ + S ₃ t ₁ = V / A, t ₃ = V / A t ₂ = (S−S ₁ −S ₃ ) / V, and the function of the moving distance s and time is s in the acceleration section. = the at ^2/2 constant velocity interval, s = at Vt + S ₁ deceleration zone becomes ^{s = Vt-at 2/2} + S 1 + S 2. On the other hand, from the specified vertical descent amount S _d, the descent amount S _e that overlaps with the horizontal movement, since represented as S = S _d + S _e, overlap of the horizontal movement and the descending operation from these equations Only one operation time, that is, a time from the start of the horizontal movement operation to the start of the lowering operation, is obtained, and a value obtained by subtracting this from the total horizontal movement time is set as the lowering operation start point. The obtained starting point of the descending operation is shown in FIG.
It is temporarily stored in one storage device.

FIG. 5 is a flowchart of control of the robot, and FIG.
The processing is performed at predetermined small time intervals using an interrupt by an internal timer of the computer. The difference between the control position of each arm in the memory device of FIG. 211 and the value of the counter in FIGS.
This is given to the D / A converters of FIGS.

6-a to 6-c show flowcharts of the composite operation according to the present invention. In the figure, at 601 the lowering operation start point is calculated, and at 602 the control is synchronized with the control shown in FIG. In 604, 608, 613, ascending, horizontal movement, the time from the start of descent are separately increased by the fixed minute time separately, and in 606, 610, 613, the ascending amount, the horizontal moving amount,
The amount of descent is calculated from each of the travel times. 607
Then, it is determined whether the actual vertical rise amount obtained from the counters 201, 204, and 207 has reached the designated vertical rise amount. If the actual vertical rise amount has reached the designated movement amount, the horizontal movement operation is started. At 612, it is determined from the horizontal movement time whether or not the descent operation start point has been calculated at 601. If the descent operation start point has been reached, the descent operation is started. At 616, the control position stored in the storage device of FIG. 211 is rewritten. Then again 602
The robot operates in synchronization with the control. 60
In 5,609, when the ascent and horizontal movement are completed, the next operation starts regardless of the vertical movement amount specified by the user.
For safety, the user may be informed before operation.

Therefore, in this embodiment, the user can easily and accurately perform the operation time only by designating the vertical ascending amount and the vertical descending amount and teaching the final positioning point without performing the teaching while performing the operation many times while being aware of the trajectory. Can be determined.

[Effects of the Invention] As described above, according to the present invention, a vertical ascent amount is provided in a robot control device that performs a gate-shaped composite operation in which a raising operation, a horizontal movement operation, and a lowering operation of a hand effector are partially overlapped. And the amount of vertical descent can be specified, so that the robot can easily and accurately teach the operation of the insertion operation and the extraction operation from above, and the operation time of the robot can be shortened. Further, when it is determined that the actual ascent amount has reached the specified vertical ascent command amount, by starting the horizontal movement operation,
Positioning can be performed very accurately.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of the entire robot and control device of the present invention. FIG. 2 is a detailed block diagram of the control device of FIG. FIG. 3 is a trajectory diagram of a composite effect hand effector according to the present invention. FIG. 4 is an operation diagram of a vertical ascending axis, a horizontal moving axis, and a vertical descending axis of a combined operation according to the present invention. FIG. 5 is a flowchart of the control of the robot performed at regular intervals. FIG. 6 is a flowchart of the composite operation according to the present invention. FIG. 6-a is an operation flow when ascending, FIG. 6-b is a horizontal movement operation, and FIG. FIG. 7 shows the trajectory of the hand effector by a method of previously specifying the vertical ascending rate at which horizontal movement is started and the horizontal ascending rate at which descending movement is started with monitoring means for ascending movement and horizontal movement. FIG. 101 I / O circuit 102,211 Storage device 103,210 Computer 104 Servo circuit 201,204,207 Counter 202,205,208 D / A converter 203,206,209 Servo drive circuit 301,401 Vertical rise 302,402 Vertical fall

Claims (2)

(57) [Claims] A gate having a drive shaft for vertically moving the position of the hand effector and a drive shaft for horizontally operating the hand effector, and performing an ascending operation, a horizontal moving operation, and a lowering operation of the hand effector in a partially overlapping manner. (A) means for monitoring the actual amount of elevation of the hand effector; and (b) a vertical ascent command amount in which the actual amount of elevation is designated by the amount of elevation monitoring means. Means for starting the horizontal movement operation by superimposing it on the ascending operation when it is determined to have reached (c) a descent operation start point capable of descending with the specified vertical descent command amount, Means for predicting from a function of time; (d) horizontal movement time monitoring means for monitoring horizontal movement time; and (e) the hand effect in the vertical descent command amount according to information from the horizontal movement time monitoring means. Lowering vessel So that the control device of the robot, characterized in that it comprises a means for initiating the downward movement superimposed on the horizontal movement by the descending operation starting point. 2. The robot control device according to claim 1, wherein the portal-type composite operation is specified by specifying the vertical ascending command amount and the vertical descending command amount in advance.