JP4475662B2 - Work assistance device - Google Patents

Description

  The present invention relates to an apparatus that assists a work performed by a worker using a tool on a rotating workpiece.

For example, in the operation of applying an adhesive around the windshield of an automobile, it is more efficient to apply the adhesive with an adhesive applicator while rotating the windshield. This is because the range in which the applicator is moved can be reduced.
In this specification, an object to be worked, such as a windshield, is referred to as a work. An instrument used by an operator for a workpiece such as an applicator is called a tool.
In Patent Document 1, a windshield glass is attached so that the periphery of the windshield moves under the coater by fixing the spreader (tool), supporting the windshield (work) by the robot, and operating the robot. A technique for rotating is disclosed.

Japanese Utility Model Publication No. 63-130389

The technique of Patent Document 1 is performed fully automatically. However, an error may occur in the support position of the workpiece by the robot, or an error may occur in the fixed position of the tool. Fully automatic requires many sensors to cope with such errors.
Therefore, it is possible to perform the operation more accurately when the operator operates the tool while rotating the workpiece to apply the adhesive.

By the way, when an operator uses a tool to perform work on the workpiece while rotating the workpiece, when the workpiece is rotated at a constant angular velocity, the tool is applied at a position where the tool is applied depending on the distance between the tool and the workpiece rotation center. The workpiece speed changes. If the speed of the workpiece at the position where the tool is applied changes over time, it becomes difficult for the operator to perform the operation. If the distance between the tool position and the workpiece rotation center is short, the workpiece moves slowly at the tool position. This is a frustrating task for the operator. If the distance between the tool position and the workpiece rotation center is long, the workpiece moves at that position at high speed. It becomes difficult for the operator to make the tool follow the target trajectory on the workpiece to which the tool is to be applied.
There is a need for a technique that facilitates work when an operator performs a work performed on a rotating work using a tool regardless of the distance between the tool position and the work rotation center.

When the work is rotated at a constant angular velocity, the work speed at the specific position increases as the distance between the specific position on the work and the rotation axis of the work rotator that rotates the work increases. The angular velocity of the work rotator that supports the workpiece (that is, the angular velocity of the workpiece) is represented by ω, and the distance between the tool position and the rotational axis in the plane orthogonal to the rotational axis is represented by R, and the speed of the workpiece at the tool position. V can be expressed as ω × R. If the angular velocity ω is constant, the workpiece velocity V at the tool position increases in proportion to the distance R.
Therefore, in the present invention, focusing on the fact that when the workpiece is rotated at a constant angular velocity, the workpiece speed at the tool position changes according to the distance between the tool and the rotation axis of the workpiece rotator, the tool position is detected and the tool is detected. The angular speed of the work rotator that rotates the work decreases as the distance between the work rotator and the rotation axis of the work rotator increases. That is, as the distance R increases, the angular speed ω of the work rotator decreases. By doing so, when the tool is located at a position far away from the rotation axis, the work speed at the tool position can be made slower than when the work is rotated at a constant angular speed. Conversely, when the tool is located near the rotation axis, the work speed at the tool position can be made faster than when the work is rotated at a constant angular speed. As a result, even if the distance between the tool position and the rotation axis is changed by moving the tool, it is possible to suppress the change in the work speed at the tool position. It is possible to easily assist the operator using the tool with respect to the rotating workpiece.

One technique disclosed in the present specification can be embodied in a work assistance device. This device is a device that assists an operator in using a tool with respect to a rotating workpiece, a tool position detector that detects the position of the tool, and a workpiece rotator that rotates the workpiece around a rotation axis. A first control unit is provided that decreases the angular velocity of the work rotator as the distance from the position of the tool detected by the tool detector to the rotation axis increases.
The tool position detector may be, for example, a sensor that attaches a magnetic sensor to a tool and detects its position. Or you may detect the position of a tool by image processing from the image using the camera which image | photographs a tool. The tool position may be a relative position (relative coordinates) with respect to the work rotator. Or the coordinate of the tool in an absolute coordinate system may be sufficient.
Further, the work rotator may be any one that rotates the work using a power source such as a motor or an engine.

  With the above configuration, the angular velocity of the work rotator can be reduced as the distance from the position of the tool to the rotation axis is longer. As a result, even if the tool is moved away from the rotation axis, the work speed at the tool position is not increased in proportion to the distance between the tool position and the rotation axis. The angular velocity of the workpiece can be adjusted so that the worker can work easily.

The first control unit controls the angular velocity of the workpiece rotator such that the speed of the workpiece at the location of the detected tool in the position detector along the rotational axis and projected onto the workpiece rotating surface position is maintained at a constant It is preferable to do.
Here, the “work speed” is expressed in other words as a work speed in a tangential direction of a circle whose radius is the distance between the rotation axis and the tool position around the rotation axis on the rotating work. You can also.

The first control unit, the operator can apply the tool to the workpiece in a state in which the work speed of the tool position is maintained at a constant. Since the work speed at the tool position is kept constant regardless of the distance between the tool position and the rotation axis, it is possible to realize a work assisting device that makes the work easier.

The present invention can immediately Fight to work auxiliary equipment. This device is a device that assists an operator in using a tool with respect to a rotating workpiece, and includes a tool position detector, a storage unit, a workpiece rotator, and a second control unit.
The tool position detector has a function of detecting the position of the tool. The storage means has a function of storing the target trajectory of the tool set on the workpiece. The work rotator has a function of rotating the work around its rotation axis. The second control unit is an angle formed by the tangential direction of the target trajectory at the position where the position of the tool detected by the tool position detector is projected onto the work rotation surface along the rotation axis and the direction of the work speed at the projected position. look has a function of values of the workpiece speed divided by the cosine of the angle at the projection position to control the angular velocity of the workpiece rotator so that a constant.
The target trajectory is a trajectory when the tool is moved on the workpiece, and is stored in advance in the storage means. The storage means may be a memory, a hard disk or other storage medium in the computer.
The cosine of the angle means cos (θ) when the angle is θ.
The tangential direction of the target trajectory is the direction in which the tool should be advanced along the target trajectory at the position where the position of the tool is projected onto the work rotation surface along the rotation axis. The angle formed between the tangential direction of the target track and the direction of the workpiece speed is expressed in other words as the angle formed between the direction in which the tool should be advanced along the target track and the direction of the workpiece speed at the projected position. You can also.

When an operator performs a work performed on a work using a tool, the tool may be desired to be moved along a target trajectory set on the work. Furthermore, in that case, it is often desirable to move the tool at a constant speed along the target trajectory. At this time, the angle between the tangential direction of the target trajectory and the direction of the work speed at the position where the position of the tool detected by the tool position detector according to the above configuration is projected onto the work rotation surface along the rotation axis is obtained. the effect of controlling the angular velocity of workpiece rotator so that the value of the work rate divided by the cosine of the angle in the projection position is a constant will be described with reference to FIG.
FIG. 4 shows a state in which the workpiece 30 is rotating at the angular velocity ω about the rotation axis C. A target trajectory L is set for the work 30. Here, a position where the position of the tool detected by the tool position detector is projected onto the workpiece rotation surface along the rotation axis is defined as a point S1. A tangential direction of the target trajectory L at the point S1 is indicated by a symbol LP. The speed of the workpiece 30 at the point S1 is VC. In addition, an angle formed by the tangential direction LP of the target trajectory L and the direction of the workpiece speed VC is defined as θS. A straight line connecting the rotation axis C and the point P is denoted by RE.
Now, assume that the tool is to be moved along the target trajectory L at a constant speed VL. For this purpose, the workpiece speed VC is set to a speed at which VC = VL · cos (θS), and the operator moves the tool at a speed VT = VL · sin (θS) in the direction of the straight line RE as shown by a broken line in FIG. You can do it. That is, by controlling the angular velocity of the workpiece rotator so that a value obtained by dividing the cosine (cos (.theta.S)) of the angular workpiece speed VC (.theta.S) is a constant (VL in the example of FIG. 4), the working If the person moves the tool at a speed VT (= VL · sin (θS)) in the direction of the straight line RE shown in FIG. 4, the tool can be moved at a constant speed VL in the tangential direction of the target trajectory. In the example of FIG. 4, the angle θS increases as the point S1 that is the tool position moves away from the rotation axis C and approaches the corner portion of the substantially rectangular target trajectory L. As a result, reduced work speed VC as a value obtained by dividing the cosine (cos (θS)) of the angular workpiece speed VC (.theta.S) becomes a constant value. Accordingly, the work rotation angular speed ω for setting the work speed to VC is also reduced.
The workpiece speed is the cosine of the angle with respect to the angle formed by the tangential direction of the target trajectory and the workpiece speed direction at the position where the tool position detected by the tool position detector is projected onto the workpiece rotation surface along the rotation axis. by controlling the angular velocity of the workpiece rotator as a value obtained by dividing becomes a constant in, even if the distance between the workpiece rotational axis from a projection position of the tool position is increased, the operator easily tool to the target track along it can be easily moved at a constant speed.

In the case of a corner portion where the target trajectory at the projected position has a radius of curvature smaller than a predetermined value, a third control unit is added to decelerate the angular velocity of the work rotator from the angular velocity controlled by the second control unit. Preferably it is.
Here, the “predetermined value” may be a preset value of the radius of curvature. In addition, the “corner portion having a radius of curvature smaller than a predetermined value” means a concept including a bent portion that is the limit where the radius of curvature converges to zero.
Further, the target trajectory may be the outer periphery of the workpiece or a curve set inside the outer periphery of the workpiece.
According to the above configuration, the rotational angular velocity of the workpiece can be further reduced in a place where the radius of curvature of the target track is small and it is difficult to move the tool along the target track. As a result, it is possible to facilitate the relative movement of the tool along the target trajectory even in a place where the radius of curvature is small and it is difficult to move the tool along the target trajectory.

The work assisting device described above preferably includes a tool moving mechanism that supports the tool and assists the worker in moving the tool.
Since the moving mechanism supports the tool, the operator does not need to support the weight of the tool, and the tool can be moved easily by the moving mechanism.

  According to the work assistance device of the present invention, when an operator performs a work using a tool on a rotating work, the distance from the rotation axis of the work rotator for rotating the work to the position of the tool is increased. It is also possible to prevent the workpiece speed at the tool position from increasing in proportion to the distance. It is possible to assist the operator so that the operator can easily perform the operation using the tool for the rotating workpiece even at the position where the distance is large.

(First Mode) A corner portion that decelerates the angular velocity of the work rotator by the third control unit to be lower than the angular velocity controlled by the second control unit refers to a portion where the radius of curvature of the target track is approximately 50 mm or less.

<Example 1>
FIG. 1 shows a schematic diagram of a work assistance device 10a according to an embodiment of the present invention. The work assisting device 10 a in this embodiment is a device that assists the work of applying an adhesive around the windshield 30 using the applicator 32. In this embodiment, the applicator 32 corresponds to an example of a tool. The windshield 30 corresponds to an example of a workpiece.
The work assisting device 10 a includes a work rotator 24 that supports and rotates the windshield 30, a moving mechanism 11 that supports the application tool 32, and a controller 22 a that controls the work rotator 24 and the moving mechanism 11.

A windshield 30 that is an object to which an adhesive is to be applied is supported by a work rotator 24 via a work rotation support shaft 26. The windshield 30 is fixed to the work rotation support shaft 26 by, for example, a suction cup (not shown) or a dedicated clamp (not shown).
The work rotator 24 includes a motor 28 and an encoder 29 that detects the rotation angle of the windshield 30 supported by the work rotation support shaft 26. The work rotator 24 rotates the work rotation support shaft 26 by a motor 28. As a result, the windshield 30 can be rotated around the rotation axis C at an angular velocity ω. The angular velocity ω of the motor 28 is set by a command value from the controller 22a. The rotation angle of the windshield 30 relative to the work rotator 24 is detected by the encoder 29. The rotation angle detected by the encoder 29 is sent to the controller 22a. Inside the controller 22a, the rotational angle of the windshield detected by the encoder 29 is differentiated to determine the actual angular velocity ω of the windshield 30.
An application line L where an adhesive is to be applied is set around the windshield 30. The operator relatively moves the applicator 32 along the application line L set on the rotating windshield 30. In the present embodiment, the coating line L corresponds to a target trajectory for moving the coating device 32 relative to the windshield 30. Hereinafter, the coating line L is referred to as a target trajectory L.

The moving mechanism 11 is fixed to the floor by a moving mechanism base 13. From the moving mechanism base 13 to the tip of the moving mechanism 11, the links 12a, 12b, and 12c and the joints 14a, 14b, and 14c that connect the adjacent links 12 in a swingable manner are connected. The joint 14a connects the moving mechanism base 13 and the link 12a. Actuators 16a, 16b, and 16c are installed in the joints 14a, 14b, and 14c, respectively. The joint group 14 is driven by the actuator group 16. Hereinafter, when the actuator group, the joint group, and the like are collectively referred to, the reference numerals without the subscripts a, b, and c are used. By the actuator group 16, the applicator 32 supported at the tip of the link 12 c can be moved to an arbitrary position within the movable range of the moving mechanism 11. The joints 14a, 14b, and 14c are provided with position sensors 15a, 15b, and 15c, respectively. The position sensor group 15 is an encoder or the like. The position (coordinates) of the applicator 32 in the absolute coordinate system can be obtained by geometric calculation from the value output from the position sensor group 15 and the connection structure of the link group 12 of the moving mechanism 11.
An adhesive is discharged from the tip of the applicator 32. A supply hose 34 for supplying an adhesive is connected to the applicator 30.
An operation element 18 is disposed on the link 12 c at the tip of the moving mechanism 11 via the force sensor 20 near the applicator 32. When the operator operates the operating element 18, the operating force is detected by the force sensor 20. The detected operating force is sent to the controller 22a. The controller 22a drives the moving mechanism 11 that supports the applicator device 32 in accordance with the sent operation force. That is, the work assisting device 10a of the present embodiment can move the applicator 32 in the direction intended by the operator by the moving mechanism 11. The operator moves the applicator 32 supported at the tip of the moving mechanism 11 along the application line L set on the rotating windshield 30 by operating the operator 18.

The controller 22 a controls the angular velocity ω of the motor 28 (that is, the angular velocity of the windshield 30) according to the distance between the position of the application tool 32 detected by the position sensor group 15 and the rotation axis C of the work rotator 24. At the same time, the controller 22a controls the moving mechanism 11 based on the operating force applied to the operator 18 operated by the operator.
Here, an outline of control of the angular velocity ω of the motor 28 by the controller 22a will be described. The controller 22 a calculates the length of the perpendicular line R taken from the position P of the applicator 32 to the rotation axis C of the work rotator 24. In addition, the point P shown in FIG. 1 is a point representing the position of the applicator 32. Further, the point Q shown in FIG. 1 is the position of the foot of the perpendicular line R. The controller 22a determines the angular velocity of the motor 28 provided in the work rotator 24 so that the angular velocity ω of the windshield 30 decreases as the length of the perpendicular line R increases (that is, as the distance from the tool position to the rotation axis increases). Control. By this control, it is possible to suppress an increase in the relative speed between the applicator 32 and the windshield 30 even when the applicator 32 is located far from the rotation axis C of the windshield 30. Even if the distance between the applicator 32 and the rotation axis C changes, the relative speed between the applicator 32 and the windshield 30 does not change greatly. it can.

Next, the configuration of the work assisting device 10a will be described with reference to the block diagram of FIG. The work auxiliary device 10a can be roughly divided into a work rotator 24, a moving mechanism 11, and a controller 22a. The applicator 32 shown in FIG. 2 is a tool and is not included in the work assisting device 10a. Similarly, the windshield 30 shown in FIG. 2 is a workpiece and is not included in the work assisting device 10a.
The work rotator 24 includes a rotation support shaft 26 that supports and rotates the windshield 30, a motor 28 that rotates the rotation support shaft 26, and an encoder 29 that detects the rotation angle of the windshield 30 relative to the work rotator 24. .
The moving mechanism 11 includes a supported application device 32, a position sensor group 15 that detects the position of the application device 32, an operation element 18, and a force sensor 20 that detects a force applied by the operator to the operation element 18. An actuator group 16 that swings each link group 12 of the moving mechanism 11 is included.
The controller 22a includes a position calculation unit 40, a rotator control unit 42, a target trajectory data storage unit 44, and a movement mechanism control unit 48. The target trajectory data storage unit 44 stores data on the target trajectory L set on the windshield 30.

The rotation angle of each joint 14 detected by the position sensor group 15 provided in the moving mechanism 11 is sent to the position detector 40 inside the controller 22a. The position detection unit 40 calculates the position (coordinates) of the applicator 32 in the absolute coordinate system by geometric calculation from the rotation angle of each joint 14 and the structure of the link group 12 of the moving mechanism 11. The calculated position of the applicator 32 is sent to the rotator controller 42.
The rotator controller 42 stores the position of the work rotator 24 in the absolute coordinate system. The position of the applicator 32 calculated by the position calculator 40 and the rotation angle of the windshield 30 detected by the encoder 29 are input to the rotator controller 42. The rotator control unit 42 specifies the position of the current target trajectory L in the absolute coordinate system from the data of the target trajectory L stored in the target trajectory data storage unit 44 and the current rotation angle of the windshield 30. An angular velocity ω to be realized by the motor 28 of the work rotator 24 is calculated from the specified current position of the target trajectory L and the position of the applicator 32. The rotator controller 42 outputs the calculated angular velocity ω to the motor 28 as a command value. The setting of the angular velocity ω to be realized by the motor 28 will be described later.

  On the other hand, the operating force detected by the force sensor 20 is input to the moving mechanism control unit 48. The operating force is a force applied to the operator 18 by the operator. Further, the rotation angle of each joint 14 of the movement mechanism 11 detected by the position sensor 15 is input to the movement mechanism control unit 48. The moving mechanism control unit 48 moves the applicator 32 supported at the tip of the moving mechanism 11 in the direction in which the operating force is applied from the input operating force and the rotation angle of each joint 14 of the moving mechanism 11. The command value to the actuator 16 of each joint 14 is calculated. The calculated command value is output to the actuator group 16 of the moving mechanism 11.

Next, the processing of the work assistance device 10a of the present embodiment will be described using the flowchart of FIG.
As shown in FIG. 3, the position of the applicator 32 is first acquired at step S300. Next, in step S302, a perpendicular line R that is lowered from the position of the applicator 32 to the rotation axis C (see FIG. 1) of the work rotator 24 is calculated.
Next, in step S304, the intersection of the projection line obtained by projecting the perpendicular R onto the rotating surface of the windshield 30 and the target trajectory L is calculated. The intersection is calculated as follows. A straight line obtained by extending the end point on the applicator 32 side of the perpendicular R is projected onto the rotation surface of the windshield 30 along the rotation axis C of the work rotator 24. The projected straight line is called a projection line. The rotation angle at each time with respect to the work rotator 24 of the windshield 30 is detected by the encoder 29. Therefore, the position of the target trajectory L stored in the target trajectory data storage unit 44 in the absolute coordinate system can be specified. The intersection of the target trajectory L and the projection line can be calculated from the positional relationship between the position of the target trajectory L at each time in the absolute coordinate system and the projection line described above. It should be noted that instead of steps S302 and S304, the detected position of the applicator device 32 is projected directly onto the rotating surface of the windshield 30 along the rotation axis C, and a point on the target trajectory L closest to the projected point is projected. It may be an intersection. The processing of step S302 and step S304 described above is a process that makes it easy to calculate on the computer the position at which the position of the applicator 32 detected by the position sensor group 15 is projected along the rotation axis C onto the rotating surface of the windshield 30. In order to do this, the perpendicular line R is obtained.
In step S306, the tangential direction of the target trajectory L at the intersection obtained in step S304 is specified.
Next, in step S308, an angle formed by the tangential direction of the target trajectory L specified in step S306 and the speed direction of the windshield 30 at the intersection is calculated. Since the speed direction of the windshield 30 is a direction orthogonal to the perpendicular calculated in step S302, it can be calculated from the direction and the tangential direction specified in step S306.
In step S309, the target speed of the windshield 30 at the intersection is calculated. The target speed is a value obtained by dividing the constant value VL by the cosine of the angle calculated in step S308 when the speed at which the applicator 30 is moved along the target trajectory is a constant value VL. The effect of setting the target speed of the windshield 30 at the intersection to a value obtained by dividing the constant value VL by the cosine of the angle calculated in step S308 will be described later with reference to FIG.
Next, in step S310, the angular speed ω of the motor 28 of the work rotator 24 for realizing the target speed of the windshield 30 at the intersection obtained in step S309 is calculated.
Next, in step S312, it is determined whether or not the radius of curvature of the target trajectory L at the intersection is equal to or less than a predetermined value. When the curvature radius of the target trajectory L at the intersection is not less than or equal to the predetermined value (step S312: NO), the process proceeds to step S314. In step S314, the angular velocity ω calculated in step S310 is output to the motor 28.

  On the other hand, when the radius of curvature of the target trajectory L at the intersection is equal to or smaller than a predetermined value in step S312 (step S312: YES), the process proceeds to step S316. In step S316, the angular velocity ω calculated in step S310 is changed to a smaller value. Specifically, for example, assume that the angular velocity calculated in step S310 is ω1. In step S316, the angular velocity command value for the motor 28 is changed to ω1 × 0.5. Thus, when the curvature radius of the target trajectory L at the intersection is not more than a predetermined value in step S312, the angular velocity calculated in step S310 is multiplied by a coefficient smaller than 1.0. By this step S316 processing, the rotational speed of the windshield 30 can be further reduced when the radius of curvature of the target trajectory L at the intersection is not more than a predetermined value. It is possible to make it easier for the operator to follow the target trajectory L even in a place where the curvature radius of the target trajectory L is difficult for the operator to follow the applicator 32. The above processing is repeated every control cycle.

Next, the processing shown in FIG. 3 will be described using a specific example with reference to FIG. For the sake of simplicity, it is assumed that the paper surface of FIG. 4 is a rotation surface orthogonal to the rotation axis C (see FIG. 1) of the work rotator 24. For the sake of simplicity, the work rotator 24 is not shown and only the rotation axis C of the work rotator 24 is shown. Further, the applicator 32 is also not shown, and only the point P representing the position of the applicator 32 is shown.
The windshield 30 rotates at an angular velocity ω about the rotation axis C. On the windshield 30, a target trajectory L to be advanced along the applicator 32 (not shown) is set. Now, it is assumed that the applicator 32 (not shown) is at the point P in the figure. In step S302 shown in FIG. 3, a perpendicular line R from the position P of the applicator to the rotation axis C is calculated.
Next, in step S304 shown in FIG. 3, a projection line RE obtained by projecting a straight line obtained by extending the perpendicular R on the applicator 32 side (point P side) onto the rotation surface (on the paper surface of FIG. 4) is calculated. Then, an intersection S1 between the projection line RE and the target trajectory L is calculated. Since the applicator 32 is advanced along the target trajectory L, the position P of the applicator 32 coincides with the intersection S1 during the operation.
In addition, as shown in FIG. 4, the position P of the applicator is the target for projecting the straight line RE extending the end point (point P) of the perpendicular R on the applicator 32 side onto the rotation surface (on the paper surface of FIG. 4). This is because the intersection of the straight line connecting the rotation axis C and the position P of the applicator with the target trajectory L can be calculated even when closer to the rotation axis C side than the track L. This is because, since the applicator 32 is advanced along the target trajectory L, the position of the applicator 32 projected on the rotating surface of the windshield 30 is positioned on the target trajectory L during the operation. This is because the position where the position of the applicator device 32 is projected onto the rotating surface of the windshield 30 may not necessarily be on the target trajectory L while the device 32 is moving. This is because even in such a case, the position of the target trajectory corresponding to the position of the applicator 32 projected onto the rotating surface of the windshield 30 along the rotation axis C can be specified. That is, in the present embodiment, even when the position P projected from the position of the applicator 32 along the rotation axis C onto the rotation surface of the windshield 30 is not on the target trajectory L, “the position of the applicator 32 is the rotation axis C The position of the “target trajectory at the position projected onto the rotating surface of the windshield 30 along” is specified in the vicinity of the point P.
Next, in step S306 shown in FIG. 3, the tangential direction of the target trajectory L at the intersection S1 is calculated. In FIG. 4, the tangential direction of the target trajectory L at the intersection S1 is indicated by a broken line LP.
Next, in step S308 in FIG. 3, an angle θS formed by the tangential direction of the target trajectory L at the intersection S1 and the speed direction of the windshield 30 at the intersection S1 is calculated. The direction of the speed of the windshield 30 at the intersection S1 is orthogonal to the straight line RE obtained by extending the perpendicular line R. A straight line passing through the point S1 and orthogonal to the straight line RE is defined as LC. The angle θS can be calculated as an angle formed by a straight line LP indicating the tangential direction of the target trajectory L and a straight line LC indicating the speed direction of the windshield 30.
Next, in step S309, the target speed VC of the windshield 30 at the intersection S1 is calculated. The target speed VC is obtained from the equation VC = VL · cos (θS). Here, VL is a speed desired to be constant when the applicator 32 is moved along the target trajectory L. For this purpose, the workpiece speed VC is set to a speed at which VC = VL · cos (θS), and the operator moves the tool at a speed VT = VL · sin (θS) in the direction of the straight line RE as shown by a broken line in FIG. You can do it. That is, by controlling the angular speed of the work rotator so that the value obtained by dividing the work speed VC by the cosine (cos (θS)) of the angle (θS) substantially coincides with the constant value VL, the operator can If the tool is moved in the direction at a speed VT (= VL · sin (θS)), the tool can be moved at a constant speed VL in the tangential direction of the target trajectory.
At the intersection S1 shown in FIG. 4, it is assumed that the radius of curvature of the target trajectory L is larger than a predetermined value. That is, the determination in step S312 in FIG. 3 is NO. Accordingly, in the flowchart of FIG. 3, the process proceeds to step S314, and the angular velocity ω calculated in step S310 is output to the motor 28.

When the intersection S1, which is a point near the position P of the applicator 32, moves away from the rotation axis C and approaches the corner portion of the substantially rectangular target trajectory L, the angle θS increases.
Further, when the rotational angular velocity of the windshield 30 is constant, the speed of the windshield 30 at the intersection S1 increases as the intersection S1 moves away from the rotation axis C.
In the above processing, the tangential direction of the target trajectory L at the position where the position of the applicator device 32 detected by the position sensor group 15 is projected onto the rotating surface of the windshield 30 along the rotation axis, and the windshield 30 at that position. Rotating the workpiece so that a value obtained by dividing the velocity VC of the windshield 30 at the projected position by the cosine (cos (θS)) of the angle θS becomes a substantially constant value VL with respect to the angle θS formed by the velocity direction. The motor 28 angular speed of the device 24 is controlled. By doing so, even if the distance from the projection position of the applicator device 32 to the rotation axis C of the windshield 30 is increased, the operator can easily move the applicator device 32 along the target trajectory L at a substantially constant speed VL. Can be easily moved.
Note that there is a relationship of VC = R1 · ω between the distance R1 between the rotation axis C and the intersection S1, the angular velocity ω of the windshield 30, and the velocity VC of the windshield 30 at the intersection S1. Therefore, even if the value of the angle θS is the same, that is, even if the target speed VC of the windshield calculated in step S309 in FIG. 3 is the same, the greater the distance R1 between the rotation axis C and the intersection S1, The angular speed ω for realizing the target speed VC of the windshield 30 is reduced.

  The function of the present embodiment can be expressed as follows when it is accurately handled by the processing of the flowchart of FIG. In other words, the present embodiment is a device that assists an operator in using a coating tool (tool) with respect to a rotating windshield (work), a tool position detector that detects the position of the tool, The storage means for storing the target trajectory of the tool set to, the work rotator that rotates the work around the rotation axis, and the straight line that extends from the tool position to the rotation axis to the tool side is the rotation axis. The value obtained by dividing the work speed by the cosine of the angle is substantially constant with respect to the angle formed by the tangential direction of the target trajectory and the direction of the work speed at the intersection of the projected line projected onto the work along the target trajectory. And a second control unit that controls the angular velocity of the work rotator.

  Next, the case where the radius of curvature of the target trajectory is smaller than a predetermined value (step S312: YES in the flowchart of FIG. 3) will be described. At the point S2 of the target trajectory L shown in FIG. 4, the target trajectory L is curved with a radius of curvature r. This curvature radius r is smaller than a predetermined curvature radius rth. In other words, the target trajectory L has a corner portion that is smaller than the predetermined radius of curvature rth in the vicinity of the point S2. When the intersection of the projection line and the target trajectory L is the position of S2, the determination in step S312 in FIG. 3 is YES, and the process proceeds to step S316. In step S316, the angular velocity ω obtained in step S310 is multiplied by a coefficient smaller than 1.0. By this process, in the corner portion where the radius of curvature of the target track L is smaller than a predetermined value, the windshield 30 is rotated at an angular velocity smaller than the rotational angular velocity of the windshield 30 when the radius of curvature of the target track L is larger than the predetermined value. Can be made. In the corner portion where the radius of curvature of the target trajectory L is small, the relative speed between the applicator 32 and the windshield 30 can be made smaller than the speed so far. Therefore, the operator can easily move the applicator 32 along the target trajectory L. The predetermined radius of curvature rth is preferably about 50 mm or less. Further, the curvature radius being equal to or less than a predetermined value includes a case where the curvature radius converges to zero, that is, a case where the target trajectory has a bent portion.

  When the applicator 32 is along the target trajectory L, the intersection S1 in FIG. 4 and the position P of the applicator match. However, the applicator device 32 may come off the target track L for some reason. In this embodiment, the position S1 of the target trajectory in the vicinity of the position (corresponding to the point P in FIG. 4) where the position of the applicator 32 is projected along the rotation axis C onto the rotating surface of the windshield 30 is It is included in the expression “target trajectory at the position where the position is projected onto the rotating surface of the windshield 30 along the rotation axis C”.

  In the above embodiment, the position sensor group 15 provided in the moving mechanism 11 and the position calculation unit 40 in the controller 22a correspond to one aspect of the “tool position detector” in the claims. Further, the target trajectory data storage unit 44 in the controller 22a corresponds to one aspect of “storage means” in the claims. Further, based on the data of the position of the coating instrument 32 and the target trajectory L, the angle formed by the tangential direction of the target trajectory L at the position of the coating instrument 32 projected onto the rotating surface of the windshield 30 and the speed direction of the windshield 30 is made. On the other hand, when the angular speed ω of the motor 28 of the work rotator 24 is controlled so that the value obtained by dividing the speed of the windshield 30 by the cosine of the angle becomes substantially constant (from step S302 to step S314 shown in FIG. 3). The rotator controller 42 (when processing is performed) corresponds to one aspect of the “second controller” in the claims. Further, in the case of a corner portion where the target trajectory L at the position projected on the windshield 30 at the position of the applicator has a radius of curvature smaller than a predetermined value, the angular velocity at which the rotational angular velocity of the windshield 30 is controlled by the second controller. Rotator control unit 42 in the case of performing the process of decelerating the angular velocity of the work rotator 24 so as to be smaller (the process of step S316 executed when the determination of step S312 shown in FIG. 3 is YES). Corresponds to one aspect of the “third control unit” in the claims.

  Next, a modification of the process for calculating the angular velocity command value of the motor 28 shown in FIG. 3 will be described. FIG. 5 shows a flowchart of processing for setting the angular velocity command value of the motor 28 in the modification. In this modification, steps S300, S302, and S314 perform the same processing as the processing of the same reference numerals shown in FIG. In this modification, after calculating a perpendicular line R about the rotation axis C of the motor rotator 24 from the position P of the applicator 32 in step S302, the angular velocity ω of the motor 28 corresponding to the length of the perpendicular line R is calculated in step S500. Set. Here, the angular velocity ω is set so as to decrease as the length of the perpendicular R increases. The above processing is repeated every control cycle. In the present modification, data of the target trajectory L set on the windshield 30 is not required. Therefore, the process of setting the angular velocity ω of the motor 28 of the rotator 24 can be simplified.

Specific examples of the setting of the angular velocity ω are schematically shown in FIGS. The horizontal axis of the graphs of FIGS. 6 and 7 indicates the length of the perpendicular line R. The vertical axis represents the angular velocity command value ω of the motor 28 and the velocity V of the windshield 30 in the direction orthogonal to the perpendicular R at the position P (see FIG. 4) of the applicator 32 in the plane orthogonal to the rotation axis C. It is. In other words, the speed V is the speed in the rotational direction of the windshield 30 at the position P of the applicator 32.
The example of FIG. 6 is an example in which ω is set so that the speed V of the windshield 30 is constant at the speed V1 without depending on the length of the perpendicular line R. When the length of the perpendicular R is represented by the symbol R, the angular velocity command value ω to the motor 28 is ω = V1 / R. That is, the angular velocity command value ω draws a curve that is inversely proportional to the distance of the perpendicular line R.
In the example of FIG. 7, ω is set so that the speed V of the windshield 30 is constant at the speed V1 until the length R of the vertical line is Rth, and the windshield 30 is set when the length R of the vertical line is equal to or greater than Rth. This is an example in which ω is set so that the velocity V decreases with a predetermined linear function with respect to the length R of the perpendicular. In FIG. 7, when the perpendicular length R is equal to or less than Rth, the angular velocity command value to the motor 28 is drawn as ω1, and when the perpendicular length R is larger than Rth, the angular velocity command value to the motor 28 is shown as ω2. Draw. The decrease rate of ω2 with respect to the increase of the perpendicular distance R is set larger than the decrease rate of ω1. When the area of the windshield 30 is large, there is a possibility that the windshield 30 may sway in a direction intersecting the rotation plane as the distance from the rotation axis C increases. By reducing the speed V in the rotation direction of the windshield 30 in the region where the distance R of the vertical line, that is, the distance between the rotation axis C of the rotator 24 and the applicator 32 is large, work in a place where the windshield 30 is likely to shake. Can be made easier.
6 and 7, the angular velocity ω of the motor 28 of the work rotator 24 is controlled so as to decrease as the length of the perpendicular line extending from the applicator 32 to the rotation axis C increases. In this modification, the target trajectory data storage unit 44 in the controller 22a and the encoder 29 in the work rotator 24 are not necessary in the block diagram shown in FIG. Further, the rotator controller 42 in the controller 22a performs the processes of Step S302, Step S500, and Step S314 in the flowchart shown in FIG. The rotator control unit 42 at this time corresponds to one mode of the “first control unit” in the claims.

<Example 2>
Next, Embodiment 2 of the present invention will be described with reference to FIG. The work assisting device 10b in this embodiment is also a device that assists the work of applying an adhesive around the windshield 30 using the applicator 32. However, in this embodiment, the operator operates the applicator device 32 by directly holding it in the hand. When the applicator 32 is light, the operator may directly hold the applicator 32 for work. In this embodiment, even in such a case, the angular velocity of the windshield 30 can be controlled according to the distance between the position of the applicator 32 and the rotation axis C of the windshield 30.
The work auxiliary device 10b of the present embodiment includes a work rotator 24 that supports and rotates the windshield 30, a position measuring device 54 that detects the position of the applicator 32 by image processing, and a controller that controls the work rotator 24. 22b. Note that parts having the same reference numerals shown in FIG. 8 and FIG. 1 represent the same parts.
The position of the applicator 32 can be obtained by a position measuring instrument 54 having two cameras 54L and 54R. The position measuring device 54 obtains the position of the applicator 32 from the images of the two cameras 54L and 54R using a position calculation method based on stereo stereoscopic vision. The obtained position of the applicator 32 is sent to the controller 22b. The controller 22b determines whether the vertical line R is lowered from the applicator 32 to the rotation axis C of the windshield 30 (that is, the distance from the position of the applicator 32 detected by the position measuring device 54 to the rotation axis C). An angular velocity command value ω of the motor 28 that rotates the glass 30 is output to the motor 28. Note that the processing of the flowchart shown in FIG. 3 or FIG. 5 can be used for the calculation processing of the angular velocity command value ω. In addition, the position measuring device 54 of the present embodiment corresponds to one aspect of “tool position detector” in the claims. Further, the controller 22b in the case where the process shown in FIG. 3 described in the first embodiment is performed corresponds to one aspect of a “second control unit” in the claims. On the other hand, the controller 22b in the case of performing the processing shown in FIG. 5 described in the modification of the first embodiment corresponds to one aspect of “first control unit” in the claims.

Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, in the second embodiment, the position measuring instrument 54 using image processing is used to detect the position of the applicator 32 (tool). In the present invention, it is not always necessary to measure the position of the tool strictly. Therefore, it is possible to use a position measuring instrument including an error as in image processing. The “tool position” may be the position of a reference point fixed to the tool, or may be the approximate position of the tool. The approximate position of the tool may be, for example, the position of the tool including an error in image processing, which is obtained by the above-described image processing.
Further, for example, the moving mechanism 11 of the first embodiment moves the applicator 32 by an actuator, but the moving mechanism 11 supports the applicator 32 in addition to the one that actively moves the applicator 32 by the actuator, and its weight. It may be a so-called balancer type moving mechanism that cancels. The balancer type moving mechanism may be a mechanism that passively moves the applicator 32 when an operator applies force to the applicator 32.
Moreover, although the application | coating operation | work of the adhesive agent to a windshield was illustrated in the said Example, an operation | work is not limited to an application | coating operation | work. The present invention can be applied to any work as long as the work is performed by an operator using a tool on the rotating work, such as a welding work on the rotating work.
Further, as a modification of the first embodiment, the second control unit is configured so that a straight line obtained by projecting a perpendicular line extending from the tool position to the rotation axis toward the tool side and projected onto the workpiece in the rotation axis direction at the intersection of the target trajectory and the target trajectory. The angular velocity of the workpiece may be controlled so that the workpiece velocity is substantially constant. That is, the angular velocity of the motor is controlled so that the velocity VC of the windshield 30 (work) at the intersection S1 in FIG. 4 is substantially constant. Thereby, the calculation process of the angular velocity of the motor can be simplified.

  The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

It is the schematic of the work assistance apparatus of the Example which concerns on this invention. It is a block diagram of a work auxiliary device. It is a flowchart figure which shows the process of a work assistance apparatus. It is a schematic diagram explaining the setting process of the angular velocity with respect to a motor. It is a flowchart figure which shows the modification of the setting process of a motor angular velocity. It is a graph which shows an example of motor angular velocity setting. It is a graph which shows the other example of motor angular velocity setting. It is the schematic of the work assistance apparatus of the other Example which concerns on this invention.

Explanation of symbols

10a, 10b: Work assistance device 11: Movement mechanisms 12a, 12b, 12c: Link 13: Movement mechanism bases 14a, 14b, 14c: Joints 15a, 15b, 15c: Position sensors 16a, 16b, 16c: Actuator 18: Operating element 20 : Force sensor 22a, 22b: Controller 24: Work rotator 26: Work rotation support shaft 28: Motor 29: Encoder 30: Windshield (work)
32: Applicator (tool)
40: Position calculation unit 42: Rotator control unit (first control unit, second control unit, third control unit)
44: target trajectory data storage unit 48: movement mechanism control unit 54: position measuring device C: rotation axis L: application line (target trajectory)
P: Position of applicator (tool)

Claims (3)

It is a device that assists the operator in using the tool for rotating workpieces.
A tool position detector for detecting the position of the tool;
Storage means for storing the target trajectory of the tool set on the workpiece;
A work rotator that rotates the work around a rotation axis;
The angle formed by the tangential direction of the target trajectory at the position where the position of the tool detected by the tool position detector is projected onto the work rotation surface along the rotation axis and the direction of the work speed at the projected position is obtained and projected. a second control unit which controls the angular velocity of the workpiece rotator so that the value of the work rate divided by the cosine of the angle is a constant in position,
A work auxiliary device comprising: In the case of a corner portion where the target trajectory at the projected position has a radius of curvature smaller than a predetermined value, a third control unit is added to decelerate the angular velocity of the work rotator from the angular velocity controlled by the second control unit. The work auxiliary device according to claim 1 , wherein Supporting the tool, the operator work assistance device according to claim 1 or 2, characterized in that the tool moving mechanism for assisting the work of moving the tool is added.

Images