JP7453000B2 - Robot systems and control equipment - Google Patents

Description

The present disclosure relates to a robot system and a control device .

2. Description of the Related Art A teaching device is known that includes a motor and a rotational position sensor in an operation section rotated by an operator (see, for example, Patent Document 1).
When the operator rotates the operating section, the rotation amount and rotation direction are detected by the rotation position sensor, and the robot is operated according to the detected rotation amount and rotation direction. On the other hand, when a robot's hand or the like receives a reaction force from the parts it handles, the reaction force is converted into motor torque and displayed as a force sensation to the operator.

In addition, the robot's movable area and the reaction force generation limit are set inside the movable area, and when the robot approaches the movable area beyond the reaction force generation limit, the reaction force is displayed to the operator with a sense of force, and the robot moves within the movable area. There is a known technology that prohibits further operations when the user contacts the user (for example, see Patent Document 2).

Japanese Patent Application Publication No. 2009-142905 JP 2017-13167 Publication

When setting the reaction force generation limit at a predetermined distance inside the movable area, if the distance between the movable area and the reaction force generation limit is too small, the operator may feel a reaction force and operate the robot in a direction to stop it. , the robot may exceed its movable range due to coasting. If the robot exceeds its movable range, the robot will stop with an alarm, which takes time and effort to restore.

Furthermore, when setting a speed limit, if the speed of the tool tip (TCP) of the robot exceeds the speed limit, the alarm will stop, and if the speed limit is exceeded, recovery work will be time consuming.
Therefore, it is desired to more reliably prevent alarm stoppage without excessively restricting operations by the operator.

One aspect of the present disclosure includes a robot, an operating device that causes an operator to input an operating command to the robot, and a control device that controls the operating device and the robot, and wherein the operating device responds to the operating command. The control device includes a reaction force generation section capable of generating a force, and the control device stores information on a robot control section that controls the robot according to the operation command input to the operation device, and an operation restriction area of the robot. and a reaction force control unit that generates a reaction force in the reaction force generation unit when the robot enters an area within a reaction force generation distance with respect to the movement restriction area, A robot system, wherein a control unit sequentially calculates a coasting distance in a direction in which the robot approaches the movement restricted area based on the operating speed of the robot, and sets the reaction force generation distance to be larger than the coasting distance. It is.

1 is an overall configuration diagram showing a robot system according to an embodiment of the present disclosure. FIG. 2 is a block diagram showing the robot system of FIG. 1. FIG. FIG. 2 is a perspective view illustrating a movable region and a motion restriction region set around a robot in the robot system of FIG. 1. FIG. 2 is a diagram illustrating a reaction force generation area in the robot system of FIG. 1. FIG. FIG. 5 is a diagram showing an example of the relationship between the reaction force generated in the reaction force generation region of FIG. 4 and the distance. 6 is a diagram showing a modification of the relationship between reaction force and distance in FIG. 5. FIG. 6 is a diagram showing another modification of the relationship between reaction force and distance in FIG. 5. FIG. 4 is a diagram showing a modification of the reaction force generation area in FIG. 3. FIG. FIG. 7 is a diagram showing the relationship between the speed and torque of the tool tip of the robot in a modified example of the robot system according to an embodiment of the present disclosure. 10 is a diagram showing a modified example of the relationship between the speed and torque of the tool tip of the robot in FIG. 9. FIG. 10 is a diagram showing another modification of the relationship between the speed and torque of the tool tip of the robot shown in FIG. 9. FIG.

A robot system 1 according to an embodiment of the present disclosure will be described below with reference to the drawings.
The robot system 1 according to this embodiment includes a robot 2, an operating device 3, and a control device 4, as shown in FIG.

The robot 2 is, for example, a vertical six-axis multi-joint robot, and is equipped with a tool S at its tip. Here, the robot 2 includes the tool S at the tip.
Each axis of the robot 2 is driven by a servo motor (not shown), and the servo motor is equipped with an encoder (not shown) that detects the rotational angular position of each axis.

The operating device 3 includes a manual pulse generator 6 that generates a number of pulses depending on the rotation angle of the dial 5. Further, the operating device 3 includes a reaction force motor (reaction force generating section) 7 connected to the dial 5.
As shown in FIG. 2, the control device 4 includes a robot control section 8 that controls the operation of the robot 2, a reaction force control section 9 that controls the reaction force motor 7 of the operating device 3, and a three-dimensional control section of the robot 2. The storage unit 10 stores model information and operation restriction area information. The robot control section 8 and the reaction force control section 9 are constituted by a processor, and the storage section 10 is constituted by a memory.

The robot control unit 8 receives pulses generated by rotation of the dial 5 of the operating device 3 and controls the robot 2 to move the tool tip point (TCP) by a distance corresponding to the number of pulses. Further, the robot control unit 8 controls the robot 2 to move the TCP at a speed corresponding to the frequency of pulses corresponding to the rotation speed of the dial 5 of the operating device 3.

The movement restricted area is an area located outside the space in which the robot 2 can operate (movable area), and is set in advance in relation to surrounding objects. In the example shown in FIG. 3, the movable region is set as a rectangular parallelepiped space, and the motion restriction region is set outside each plane forming the outline of the movable region as a boundary. The movable region and the restricted movement region may have any shape.

The robot control unit 8 calculates the position of the outer surface of the robot 2 at each time based on the rotational angular position of each axis detected by the encoder and the information of the three-dimensional model stored in the storage unit 10. Then, the robot control unit 8 monitors whether or not the calculated outer surface of the robot 2 interferes with the motion restriction area at any position, and if so, issues an alarm and moves the robot 2 (alarm stop).

The reaction force control unit 9 has a reaction force generation boundary surface (boundary surface) that starts generating a reaction force at an interval parallel to the boundary surface inside the boundary (within the movable region) constituting the motion restriction region. Set. Then, the reaction force control unit 9 receives information about the outer surface of the robot 2 calculated by the robot control unit 8.

The reaction force control unit 9 determines whether the received outer surface of the robot 2 is located within the area (reaction force generation area) between the reaction force generation boundary surface and the boundary of the motion restriction area at any position. monitor. When the outer surface of the robot 2 is located within the reaction force generation area, the reaction force control unit 9 drives the reaction force motor 7 of the operating device 3 to cause the dial 5 to generate a reaction force.

In the present embodiment, the reaction force control unit 9 causes the robot 2 moving at the moving speed to come to an emergency stop based on the moving speed of the TCP of the robot 2 that operates by rotating the dial 5 of the operating device 3. Calculate the coasting distance in the direction approaching the motion restriction area. Then, as shown in FIG. 4, the reaction force control unit 9 sets a value larger than the calculated coasting distance as the distance from the boundary of the motion restriction area to the reaction force generation boundary surface (reaction force generation distance). Set. For example, a value of coasting distance + α (α is a positive real number) is set as the reaction force generation distance.

The reaction force generation boundary surface is sequentially updated, for example, at every fixed sampling time, until the surface of the robot 2 comes into contact with the reaction force generation boundary surface. Further, the reaction force generation boundary surface is maintained once the surface of the robot 2 enters the reaction force generation area until the next time the surface of the robot 2 leaves the reaction force generation area.

Then, the reaction force control unit 9 controls the robot 2 so that when a part of the outer surface of the robot 2 is located within the reaction force generation region, the distance between the outer surface of the robot 2 and the motion restriction region becomes close, as shown in FIG. The reaction force motor 7 is controlled so as to generate a large reaction force accordingly. That is, when the robot 2 is moving toward the movement restricted area, the reaction force motor 7 is activated at a position where the outer surface of the robot 2 contacts the reaction force generation boundary surface, and a relatively small reaction is generated. force is generated. As the robot 2 further moves within the reaction force generation area and the distance to the movement restriction area becomes smaller, the reaction force generated by the reaction force motor 7 increases.

On the other hand, in a state where a part of the outer surface of the robot 2 is located within the reaction force generation area, no reaction force is generated when the dial 5 is operated to move the robot 2 in a direction away from the movement restricted area. Therefore, the operator can move the robot 2 in a direction away from the movement restricted area and easily remove the robot 2 from the reaction force generation area.

The operation of the robot system 1 according to the present embodiment configured in this way will be described below.
According to this embodiment, when the operator rotates the dial 5 of the operating device 3 to operate the robot 2, a reaction force is applied to the dial 5 by the operation of the reaction force motor 7, so that the robot The operator can be made aware that the outer surface of No. 2 has approached the movement restricted area.

Furthermore, if the operator continues to rotate the dial 5 while feeling a reaction force on the dial 5, the reaction force applied to the dial 5 increases, causing the outer surface of the robot 2 to move closer to the movement restriction area. The operator can be made aware of this.
Then, when the operator feels the reaction force of the dial 5 and stops the dial 5, the robot 2 coasts and approaches the motion restriction area.

In this case, according to the robot system 1 according to the present embodiment, the reaction force generation distance is set to the coasting distance + α, so even if the robot 2 coasts, the robot 2 does not enter the movement restricted area. 2 can be stopped. This has the advantage that it is possible to prevent the robot 2 from stopping due to an alarm.

As the surface of the robot 2 approaches the movement restricted area, the reaction force applied to the dial 5 increases, so that it becomes difficult for the operator to rotate the dial 5 against the reaction force. The operating speed of the robot 2 is set according to the rotational speed of the dial 5, so when the surface of the robot 2 approaches the movement restricted area, the operating speed of the robot 2 gradually decreases, and the coasting distance becomes shorter. Therefore, even when the robot 2 is stopped at a position close to the movement restriction area, it is possible to prevent the robot 2 from entering the movement restriction area and causing an alarm stop.

In the present embodiment, when the surface of the robot 2 is located within the reaction force generation area, the reaction force generated is increased as the surface of the robot 2 approaches the movement restriction area. In this case, the reaction force may be increased linearly in proportion to the distance from the reaction force generation boundary surface, or may be increased non-linearly as shown in FIG. .

Furthermore, in this embodiment, the reaction force generation distance is set equal to the coasting distance + α, but instead, the reaction force generation distance can be calculated by multiplying the coasting distance by a proportional coefficient larger than 1. You can.
Furthermore, in this embodiment, the reaction force is maximized when the surface of the robot 2 coincides with the motion restriction area. Alternatively, as shown in FIG. 7, the generated reaction force may be maximized when the surface of the robot 2 is located at a predetermined distance β from the movement restricted area.

Furthermore, in the present embodiment, the reaction force generation boundary surface is generated in a position parallel to the motion restriction area and further away than the coasting distance of the robot 2.
Instead, the control device 4 moves the three-dimensional model in the virtual space in synchronization with the movement of the robot 2, and the reaction force control unit 9 moves around the three-dimensional model as shown in FIG. , an occupied area may be set. The occupied area is an area that the three-dimensional model occupies in the virtual space until it coasts and stops.

Then, a reaction force generation boundary surface is generated at a position parallel to the motion restriction area and separated by a predetermined distance γ, and a reaction force is applied to the dial 5 in a state where the occupied area and the reaction force generation area overlap. You may also do so. This produces the same effects as this embodiment.
Alternatively, the distance from the outer surface of the three-dimensional model to the outer surface of the occupied area may be set larger than the coasting distance without setting the reaction force generation boundary surface.

In addition, in this embodiment, the reaction force applied to the dial 5 increases as the surface of the robot 2 approaches the motion restriction area, but instead of this, the speed of the tool tip point TCP of the robot 2 increases. It is also possible to adopt a device that increases the reaction force applied to the dial 5 depending on the situation.

In this case, the storage unit 10 stores the speed limit of the tool tip point TCP of the robot 2 set by the operator. Then, when the speed of the tool tip point TCP of the robot 2 exceeds a predetermined speed (predetermined threshold), the reaction force motor 7 is caused to generate a reaction force. The reaction force to be generated increases in accordance with an increase in the speed of the tool tip point TCP of the robot 2, and is applied so that the running speed does not exceed the speed limit set in the storage unit 10.

As a result, when the operator rotates the dial 5 of the operating device 3 to operate the robot 2, a reaction force is applied to the dial 5 by the operation of the reaction force motor 7, thereby causing the tool tip of the robot 2 to move. The operator can be made aware that the speed at point TCP has approached the speed limit.

Furthermore, if the operator continues to rotate the dial 5 while feeling a reaction force on the dial 5, the reaction force applied to the dial 5 will increase, and the speed of the tool tip point TCP of the robot 2 will reach the speed limit. The operator can be made aware that the object is getting closer.
Therefore, even if the speed of the tool tip point TCP of the robot 2 increases, the robot 2 can be stopped without exceeding the speed limit. This has the advantage that it is possible to prevent the robot 2 from stopping due to an alarm.

Further, in a state where the speed of the tool tip point TCP of the robot 2 exceeds a predetermined speed, the reaction force generated is increased as the speed of the tool tip point TCP of the robot 2 approaches the speed limit. In this case, the reaction force may be increased linearly in proportion to the speed of the tool tip point TCP of the robot 2, as shown in FIG. 9, or as shown in FIG. It may also be increased non-linearly.

Further, as shown in FIG. 11, the reaction force may be generated by digitally applying torque according to the speed of the tool tip point TCP of the robot 2.

1 Robot system 2 Robot 3 Operating device 4 Control device 7 Reaction force motor (reaction force generation part)
8 Robot control section 9 Reaction force control section 10 Storage section

Claims (6)

robot and
an operating device that allows an operator to input operating instructions for the robot;
comprising the operating device and a control device that controls the robot,
The operating device includes a reaction force generating section capable of generating a reaction force in response to the operation command,
The control device includes a robot control unit that controls the robot according to the operation command input to the operating device, a storage unit that stores information on a movement restricted area of the robot, and a storage unit that stores information on a movement restricted area of the robot, and a storage unit that stores information on a movement restricted area of the robot. a reaction force control unit that generates a reaction force in the reaction force generation unit when the reaction force generation unit enters a region within a reaction force generation distance,
The reaction force control unit calculates a coasting distance in a direction in which the robot approaches the motion restriction area based on the operating speed of the robot, and sets the reaction force generation distance to be larger than the coasting distance. robot system. a state in which the reaction force control unit sets a boundary surface at a position separated by the reaction force generation distance inward from the movement restriction area, and the robot enters an area between the boundary surface and the movement restriction area; The robot system according to claim 1, wherein the reaction force generating section generates a reaction force. The control device includes a three-dimensional model of a robot that operates in virtual space in synchronization with the movements of the robot,
The reaction force control unit calculates an occupied area that the three-dimensional model occupies in the virtual space until it coasts to a stop, and also creates a boundary surface at a position a predetermined distance away from the movement restriction area. 2. The robot system according to claim 1, wherein the reaction force generating section generates a reaction force in a state where the occupied area enters an area between the boundary surface and the motion restriction area. A control device that controls a robot according to operation commands input by an operator,
at least one memory that stores a motion restriction area of the robot;
at least one processor;
The processor instructs the robot to generate a reaction force in response to the operation command when the robot enters within a reaction force generation distance or less with respect to the movement restriction area, and also causes the robot to approach the movement restriction area. A control device that calculates a coasting distance in a direction in which the robot moves based on an operating speed of the robot, and sets the reaction force generation distance to be larger than the coasting distance . A boundary surface is set at a position a reaction force generation distance inward from the movement restriction area, and the reaction force is generated when the robot enters an area between the boundary surface and the movement restriction area. 4. The control device according to 4 . comprising a three-dimensional model of a robot that moves in virtual space in synchronization with the movements of the robot;
In addition to calculating the occupied area that the three-dimensional model occupies in the virtual space until it coasts and stops, a boundary surface is set at a position a predetermined distance inward from the movement restricted area, and the occupied area is calculated. 5. The control device according to claim 4, wherein the control device generates a reaction force when the boundary surface enters a region between the boundary surface and the motion restriction region.

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