JPS63150170A - Operation type manipulator - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

In accordance with a command signal operated by an operator, this invention
This invention relates to a manipulator that performs arbitrary work.

[Prior art and its problems]

As this type of manipulator, a joystick type and a mask/slave manipulator type are known. Figure 5 shows the principle of the joystick. In the figure, when the lever 1 is tilted to the left or right, the shaft 3 rotates, and this is detected by a bulge meter 5. The back and forth movement of the lever 1 tilts the entire frame 6, rotates the shaft 7, and is detected by the potentiometer 9. When lever 1 is rotated, potentiometer 2 is operated directly to detect this angle. 4゜8 are shaft 3,
7, and the frame 10 is used by being fixed at an appropriate location. In this way, a signal with three degrees of freedom is generated by separately detecting the longitudinal movement of the lever and the horizontal movement perpendicular to this using potentiometers or encoders, and then adding rotation of the lever as necessary. do. Furthermore, depending on the inclination of the lever, the speed at the tip of the manipulator or the rotational speed of the motor that drives the manipulator is often controlled. The manipulator operated by this requires three degrees of freedom for positioning the wrist position in three-dimensional space and controlling the posture of the distal wrist portion. Some manipulators have seven or more degrees of freedom with redundancy for collision avoidance, etc., but most joystick-type manipulators are limited to six degrees of freedom or less. In the most common case of six degrees of freedom, two sets of the aforementioned joysticks would be used. In the case of the joystick method, if the manipulator is tilted at a certain angle, the manipulator will move in the specified direction according to the time in between, strictly speaking in proportion to the integral amount of the tilt angle. Specifically, by solving the manipulator equation, we can calculate the motor rotation angle of each axis and the manipulator tip position. Since the relationship between the postures is determined, this is executed by controlling the rotational speed of each motor as a function of time. Therefore, the operator can manipulate the position and posture of the manipulator within the space that the manipulator can reach without moving his hands much by simply tilting the joystick, so the force required for operation is small and fatigue is low. On the other hand, the signal given by the joystick is based on speed, and the actual movement of the manipulator that is to be controlled is position, so it is difficult to intuitively understand the correspondence between them and requires a certain degree of skill. In other words, this means that spatial intuitiveness is lacking, and for example, it is quite difficult to draw a circular arc with the tip of the manipulator. Also, because of the speed signal, even if the force sensation described later is returned to the joystick mechanism, it is difficult to grasp the relationship between position and force.
This method has the disadvantage that it is difficult for an operator to sense that the manipulator has come into contact with an object, or to have the manipulator remotely perform operations such as fitting between works or turning a crank. Next, FIG. 6 shows a configuration diagram of the manipulator represented by graphical symbols of motor functions. For example, consider a case where the master manipulator and slave manipulator are made to have the same shape, and for the sake of simplicity, have the same size and structure. In FIG. 6, the manipulator rotates the upper body part 19 with respect to the lower body part 18 by the joint 11 for rotation of the body part, and the upper arm part 20 moves upward and downward along the plane of the paper by the shoulder joint 12. be swayed. Further, the lower arm portion 21 further swings along the plane of the paper due to the joint 13 of the sealing portion. Thereby, the position of the tip portion 17 is determined with respect to the entire space. Furthermore, the wrist joint 14,
15.16 determines the wrist posture. The concrete structure of the above-mentioned contents is shown in FIG. here,
Only the seal will be explained. In addition, the same figure (al is a top view of the manipulator arm structure, the same figure (b) is a top view of another manipulator arm structure, the same figure (cl is the previous one (al, (b)
) is also a side view common to both. Further, members having the same function are given the same reference numerals. In FIG. 7, the joints 13 of the upper arm 20 and lower arm 21 are positioned by the movement of a motor 22. As shown in FIG. 23 is a tachogenerator which is a speed sensor and is used to impart a damping effect, 24 is an encoder which is an angle sensor, and 25 is a speed reducer attached to the motor. In some cases, the angle may be detected using 26 potentiometers. Reference numeral 27 denotes a force sensor section, for example, as shown in the figure, a beam section for generating strain is provided between the morph axis and the arm section, and the force acting on the joint section is detected by a strain gauge. By constructing a control system as shown in FIG. 8 using the above-mentioned members, position control as a mask slave is performed. That is, when the operation section 31 on the mask side is moved, this movement θ1 is detected by the encoder 32 on the mask side and is given to the controller 33 as a position signal. This causes the slave-side motor 34 to rotate, and this movement θ2 is detected by the slave-side encoder 35, fed back, and compared with the signal from the encoder 32. Note that T2 is the load torque on the slave side. In this way, the operator grasps the operation part on the mask side,
Move it in the desired direction and position the wrist posture. That is, by placing an angle sensor such as a potentiometer or encoder in each joint and using this as a command signal to control the rotation angle of a motor placed on the slave side, it is possible to cause the mask and slave to perform the same operation. In this case, since the correspondence between the mask and the slave is clear, it has excellent spatial intuitiveness and good operability. However, in reality, the weight of the manipulator acts directly on the operator and it is necessary to support this weight. Of course, it is possible to balance the weight mechanically, but this would make the mechanism extremely complex. Furthermore, having to reach out and operate the required spatial range places a burden on the operator, causing fatigue. However, as mentioned above, the mask slave manipulator system has the advantage that it is easy to provide so-called force feedback, which gives a force sensation to the operator. Next, a description will be given of the bilateral control of the mask/slave manipulator that includes position control and force feedback. In the configuration shown in FIG. 9, when the master-side operating unit 31 is moved, the encoder 32 detects the angle θ1, and this value is given to the controller 33 as a position signal. As a result, the slave side motor 34 rotates,
The encoder 35 on the slave side detects this movement θ2,
It is fed back to the controller 33 and position control is performed. At this time, when a force acts on the slave side, the force sensor 38 detects the magnitude of this force and provides it to the controller 39 as a force command signal T2. This causes the mask-side motor 36 to operate and rotate until the command value is reached. By detecting the magnitude of this force by the force sensor 37 on the mask side (detected value Tl), the force on the slave side can be transmitted to the mask side. In other words, when the operator holds the operation part on the mask side and manipulates the wrist position and posture, the movement of each joint is detected by the angle sensor, and this is used as a command signal to control the rotation angle of the motor of the corresponding axis on the slave side. do. Note that feedback is taken from the output of the slave angle sensor. As a result, the slave side also assumes the same wrist position and posture as the mask side. At this time, the slave side
When the slave joint hits an obstacle that obstructs its movement, the rotation of the motor of the slave joint is suppressed. This is detected as torque (or force) by a torque sensor, so
The motor on the corresponding mask side is rotated using this torque value as a command signal, and the torque of this motor is controlled to be the same as that on the slave side. Since the operator receives this torque or force, he is aware of contact with an obstacle on the slave side and moves the mask side in a direction to weaken the force. This changes the position of the slave side, making it possible to avoid contact. However, by adding this force sensation, the slave-side force always acts on the operator. In other words, if a slave handles a heavy object, the operator of this station will bear the burden directly. Furthermore, each time the position and posture of the slave changes, a change in gravity occurs, and this result is also fed back to the operator. Due to these effects of gravity, it is difficult to distinguish it from forces caused by contact, etc., which we want to know directly, and therefore sensitivity decreases. There is a method of using a computer to eliminate the influence of gravity, but it requires correction depending on the position and orientation of the slave manipulator, which requires extremely complex calculations and requires a large-capacity computer. Become. The above explanation has been given for the same shape and size for simplicity, but in order to avoid reducing the burden on the operator, it is possible to change the sensitivity of 1 to 1 lux or force, or change the dimensions of the mask and slave. is normal. In some cases, even the shape can be changed, but this requires calculations on a computer and is even more complicated. However, the ratio between the mask and the slave cannot be too large, and the mask itself has to be large. Therefore, if there are spatial constraints, this becomes an obstacle. As described above, the two typical types of manipulators have their own advantages and disadvantages.

[Purpose of the invention]

It is an object of the present invention to eliminate the drawbacks of these two methods and provide an excellent operating manipulator that combines the advantages of both methods.

[Key points of the invention]

Analyzing the work performed with a manipulator, it is found that rather than requiring an arbitrary trajectory to be drawn over a wide area, the tip of the manipulator is applied to a fairly limited position in the space, and in the vicinity and in a limited area. They often perform a series of tasks in a closed space, such as drawing an arc with the tip of a manipulator or turning a crank. This invention uses a joystick method, that is, a speed command method, to position the tip of the manipulator to the work point, and a mask slave method to position the manipulator tip within a limited space for actual work. , in other words, the signals of the same operating device are selectively switched as in the case of a position command, and only when a position command is given, force feedback is applied to the operating device to give the operator a sense of force. It is. In particular, there are many requests to perform work while changing the wrist position without changing the wrist posture relative to absolute space. x, y, at the tip
By installing a 3-axis force sensor in the z direction and driving an actuator in the operating device according to the output of this force sensor, a force sensation can be given to the operator with a simple structure and without complicated calculations. is possible. In other words, in this type of work, it is easy to visually position the tip of the manipulator close to the work target equipment using a joystick method, or to repeat the teaching, and it is also easy to do so without the need for the end effector, such as the wrist or a tool held on the wrist, to come into contact with some object. If this happens, it can be detected by a force sensor and an alarm can be immediately issued or the system can be stopped.
It is not necessarily necessary to provide the operator with a feedbank as a force sensation. It is sufficient to switch to the mask-slave method only when performing work in a limited space to give a sense of space and add a sense of force to allow delicate work to be performed. Within this limited space, if the position of the slave manipulator itself is limited so that it does not change significantly, changes in gravity due to changes in the manipulator position can be almost ignored, so there is no need to perform gravity compensation using a computer, and the workpiece By extracting only the change in force caused by contact, there is an advantage that the operator can be given a sense of force with sufficient sensitivity. In addition, if it is necessary to move the wrist position while changing the wrist posture, it is possible to add a wrist mechanism with the same shape as the slave to the operation device, and provide an actuator for both the mask and slave, as well as a position sensor and a force sensor. , it is possible to apply high lateral force feedback to changes in wrist posture. Another key point of this invention is changing the position command sensitivity of the mask slave when switching from speed command to position command and returning to speed command, or when reaching the limit of the target space during position command. In addition, when extending the target space, it is necessary to prevent abnormal commands from entering the slave manipulator, which is the control target. For this reason, the actuator is equipped with a spring to mechanically return it to the neutral equilibrium position, and it is also possible to switch between the joystick method and mask slave method, change the sensitivity, and modify the operating range only at the neutral equilibrium position. It is designed to provide an interlock to the Here, we have explained the return method using a mechanical spring, but its purpose is when the operator does not operate the operator, that is, when the operator releases his/her hand at a position other than the neutral position, or when the operator accidentally operates the changeover switch. This is to prevent possible out-of-control behavior. For example, a limit switch or the like may be provided in the grip section, and the actuator may be controlled so that it automatically returns to the neutral position when the grip is released. Also, even if you accidentally operate the switch, all you have to do is return it to the neutral position and accept the signal.

[Embodiments of the invention]

Figure 1 shows one of the embodiments of the present invention, and the same figure (al is a perspective view of the operating device in this embodiment, the figure numeral is the same bottom view, and the same figure (c) is the previous one. fb) It is a sectional view taken along line A-A at 4 points. The operating device is an X-axis slide part 41° and a Y-axis slide part 42. Since the Z-axis slide section 43 is combined to form an orthogonal coordinate system with three degrees of freedom, each has a motor 44, 45, 46, and the slider 47 and the Y-axis slide section 42 are connected to the slider 48 and the Z-axis slide section. 43 are connected to each other, and the slider 49 is provided with a handle 50. In the sliding part 41, a pulley 53 is combined with a motor 44 in a frame 57, another pulley 54 is held at the other end by a bearing 56, and two pulleys 53 and 54 are connected to a timing belt, that is, a toothed bell 1-52, etc. Directly connected. Then, a slider 47 is attached to this. An encoder 51 is combined with the motor 44. Furthermore, when performing feedback, a force sensor (lux sensor) not shown is incorporated into the motor output section, for example, the pulley 53. It is smoothly guided by rollers 58 and 59. For example, roller 59 is
The structure is such that more than one of them are provided, and each side of the parallel track is in contact with the other to eliminate looseness. In such a configuration, by grasping and moving the handle 50, these movement amounts are determined by the encoders 51, 55.
Detected in In the case of the joystick method, these movement amounts are given as speed signals in the X, Y, and Z axis directions of the tip of the slave manipulator. Accordingly, the controller controls the rotational speed of the motors 44, 45, and 46 for each axis based on the maniplane equation. Note that the posture of the wrist is determined by another three-degree-of-freedom joystick (not shown). This positions the user near the equipment to be worked on, and then returns the handle 50 to its original position. At this point, the system is at a neutral equilibrium position, which will be described later, so the system is switched to the mask slave system. When the handle 50 is thereby moved, the amount of movement is directly detected by the encoder 51 as a position signal. Therefore, by appropriately selecting the movement ratio of the mask and the slave, position signals for the x, y, and z axes of the tip of the slave manifold are given according to this ratio. Based on these position signals, the controller Controls the rotation angle of the shaft motor. At this time, when the tip of the slave collides with something, a three-dimensional force sensor (not shown) detects the components of the force in the x, y, and z axes, and this force is magnified or reduced at a fixed ratio. If this is the force signal from the controller installed on the controller side, the motor on the controller side will be rotated according to this value, and the force will be detected by a force sensor inside the controller (not shown). Control power. This force is directly returned to the operator's handle, so when the operator moves the handle in a direction where the force decreases, the position signal changes and the slave manipulator is moved in a direction where the slave manibrake is no longer in contact. In FIG. 2, a joystick 60 with three degrees of freedom is provided on the handle portion of FIG. 1, and the posture of the wrist is directly controlled by this joystick 60. The other configurations are exactly the same as in Figure 1,
Identical members have the same reference numerals. This allows operation with only one hand. In this case, as in the case of FIG. 6 showing the conventional example, when controlling the posture of the wrist, only the joystick method is used, and force feedback cannot be taken. FIG. 3 shows another embodiment of the invention. This is a wrist part 62 that has almost the same shape as the slave manipulator attached to the handle part shown in Fig. 1, and the axes 63° and 64.65 are perpendicular to each other, and each axis is connected to a motor, a sensor, an encoder, etc. configured. In this case, a force sensor is also required on the wrist of the slave. The wrist tip positioning system may be replaced by a three-dimensional force sensor at the wrist tip. In this case, when the operator operates the handle, it is possible to simultaneously change the posture of the wrist and the position of the tip of the wrist. In addition, in this method, switching the wrist posture to the joystick method has little meaning when considering actual work, so only the wrist positioning is switched between the joystick method and the mask slave method, and the wrist posture is always controlled by the mask slave method. It is better to use the slave method. Since this part is completely the same as that in FIG. 1, the explanation will be omitted. Next, referring to FIG. 4, an example of switching between the joystick method and the mask/slave method of this embodiment will be explained. The configuration of FIG. 4 is substantially the same as that of FIG. 1, and the same members are designated by the same reference numerals. Mounting plates 66 are newly provided on each of the x, y, and z axis slide sections, and the one in the center is attached to the slider 48, and the ones at both ends are attached to the frame 57 (Fig. 1 (C).
)) between which the spring 69 is attached.
are selected and provided so that they are balanced at an equilibrium position. A proximity sensor 67 detects the equilibrium position, and may be a high frequency oscillation type sensor or a mechanical microsinch. Reference numeral 68 denotes a dog provided on the timing belt 52, and is attached so as to be detected by the sensor 67 at the equilibrium position. 70 is a grip switch provided on the handle 50;
It is detected that the operator has removed his hand from the handle 50. In the configuration shown in the figure, if you operate the joystick and move it from the equilibrium position and position it at the required position, it will always return to the equilibrium position, so at this point a switch (not shown) is switched to the mask/slave system. Then, once the series of movements is complete, return the arm to its original position. However, since it is not necessarily at an equilibrium point at this time, if the joystick method is used at that point, it is possible that the system will run out of control. Therefore, even if the controller switches to the joystick method, an interlock function is provided so that the controller returns to the equilibrium position, detects this point, and then operates the joystick method. This can be done automatically with sensors and motors, or
It is also possible to remove the hand, detect it with the grip switch 70, and return it to the equilibrium position by the motor so that the changeover switch can be operated. Alternatively, it may be returned mechanically with a spring as shown in the figure. In any case, it is necessary to enable switching only when the equilibrium point detection sensor is ON. This is necessary even when a limit position is reached during mask-slave operation and a new equilibrium point is set to continue operation or the position ratio is changed.

【Effect of the invention】

According to this invention, the command signal of the operating device is used as a speed command to position the wrist of the slave manipulator in the vicinity of the work object, and in the limited space of the work object, the command signal is switched to a position signal to control the operation device and the slave manibrake. By providing spatial intuitiveness and at the same time making it possible to provide the operator with a sense of force through force feedback, operability is improved, and the burden placed on the operator of the mask slave method is reduced and limited. In a space where the force at the equilibrium position is used as a reference, by feeding back only the change, it is possible to eliminate the need for gravity correction due to a change in the position of the slave manipulator, and to maintain force sensitivity without complicated calculations. In addition, by controlling the actuator of the positioning device of the slave wrist position using the 3-axis force sensor signal placed on the slave wrist and performing the feed bank, it is possible to perform force feed banking by controlling the actuator of the actuator for positioning the slave wrist position. It is also possible to impart a sense of force with a simple configuration. Furthermore, by providing a joystick on the handle of the operating device, it becomes possible to control the wrist posture and position with one hand. Similarly, by providing a wrist in the handle part and configuring it with an actuator and a sensor for each force and position, as with the slave wrist, it is possible to control the wrist posture and position with one hand, and add a force sensation to all. is possible. Another advantage of the present invention is that by using the operating device in an orthogonal coordinate system, it is possible to achieve the best spatial intuitiveness and to simplify calculation of transformation. In addition, the equilibrium position sensor on the operating device and the grip sensor on the handle allow the operator to easily remove his/her hand or accidentally select or change the operating method.
By ensuring that the handle portion once reaches the equilibrium position, it is possible to prevent the slave manipulator from running out of control. Although an example of a rectangular coordinate system is shown as an operating device of the present invention, it is not necessarily limited to this coordinate system, and although there are differences in the formulas calculated by the controller in polar coordinate system and cylindrical coordinate system, However, the effect of the present invention is not limited even if it is applied to any of the above. Although the actuator is shown as a combination of a motor and a timing belt, for example, a combination of a hydraulic cylinder and a servo valve can be used to control flow rate and pressure to perform positioning and feedback. Similar effects can be obtained by using other pneumatic actuators, or by using a force coil type (electrodynamic type) as a linear actuator. In addition, we have explained a configuration in which a force sensor or a torque sensor is provided for each of the three axes of the motor as a force sensor on the operating device side. A configuration in which the handle is operated is also possible, and the same effect can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows the operating device of the present invention, (al is a perspective view, fbl is a bottom view, and
2 is a perspective view of an operating device according to another embodiment of the present invention. FIG. 3 is a perspective view of an operating device showing yet another embodiment of the present invention. A configuration diagram of an operating device showing still another embodiment of the present invention, FIG. 5 shows a conventional joystick, and FIG. Figure 7 shows the structure of a conventional manipulator using graphical symbols representing its motor functions.
al is - Top view of the arm structure of the manipulator, same figure 0))
is a top view of the arm structure of another manipulator, FIG. 8 (C) is a side view common to the previous figures (a) and (b), and FIG. FIG. 9 is a block diagram of conventional mask slave bilateral control. Code explanation 4L42, 43 Nishlide part, 44145146
: Motor, 47, 48, 49 Nislider, 50, 61
: Handle, 51.55 F encoder, 52:
Timing belt, 53.54: Pulley, 57: Frame, 58.59: Roller, 60: Joystick, 62: Wrist, 63: Rotating shaft, 64, 65:
Swing axis, 66: Mounting base, 67: Proximity sensor, 68: Dog, 69 Spring, 70: Grip switch. Part 1 (a) Trillion 1 side (c) Anger 3 31, 3834″TI'r2, ),) Ho 7 Figure 9th leap

Claims (1)

[Scope of Claims] 1) An operating type manipulator comprising an operating device including an actuator and a handle portion, and a manipulator including a force sensor, and which performs a work according to a command signal output from the operating device, The command signal is selectively switched to a speed command or a position command, and only when the command signal is a position command, the actuator is controlled and the force is fed back based on the output of the force sensor. An operation type manipulator characterized by the following. 2) In the manipulator according to claim 1, the force sensor detects force in each of three axial directions.
An operation type manipulator which is an axial force sensor, and wherein an actuator of the operation device has three axes corresponding to the three axis directions, and the actuator is controlled using forces in each of the three axis directions as a command signal. . 3) The manipulator according to claim 2, characterized in that a three-degree-of-freedom joystick for wrist posture control is provided on the handle portion of the manipulator. 4) In the manipulator according to claim 2, the manipulator has the same configuration as the wrist of the slave manipulator, and includes an actuator and a position sensor, or an actuator, a position sensor, and a force sensor. An operating type manipulator characterized in that a wrist portion of the controller is provided in a handle portion of the operating device. 5) In the operating manipulator according to claim 1, the operating device is provided with an orthogonal three-axis sliding section that includes an actuator and a position sensor, or an actuator, a position sensor, and a force sensor. An operable manipulator featuring: 6) In the manipulator according to claim 1, an equilibrium position detection sensor corresponding to each of the three mutually independent axes is provided on the operating device, and a gripping sensor is provided on the handle portion, and the output of the gripping sensor is ON or O
When FF, return the handle to the equilibrium position,
And only when the equilibrium position detection sensor detects that the handle portion is in the equilibrium position, the operating range of the manipulator, the sensitivity of the force sensor, or the command signal can be switched between the speed signal and the position command. An operation type manipulator characterized by the following.