JPS6377670A - Master/slave manipulator - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a master/slave manipulator, and more particularly to a master/slave manipulator having a mask manipulator and a slave manipulator having mutually different axis configurations.

[Conventional technology]

A well-known conventional master-slave manipulator is one in which the mask and slave manipulators have the same shaft configuration, as shown in Figure 3 (Manipulator Type Book 5, by Keller, 1981). P5
~P41: Ni, W.

K OHL E R; Manipulator 1l
andbook) *In other words, as shown in Figure 3,
Master manipulator 10 and slave manipulator 2
o has the same (or similar) axis configuration, and each axis has actuators 12 (12a to 12a) in one-to-one correspondence.
12f) and 22 (22a to 22f) are provided,
A handle 11 that is operated by an operator and a hand 21 that actually performs operations are provided at the tip of the arm formed by them. Then move the J handle 11 to the indicated arrow 10
When the hand 21 of the slave manipulator is moved as shown in FIG. 1, the hand 21 of the slave manipulator is moved as shown by an arrow 102 along with the movement.

In such a master/slave manipulator,
In order to transmit the reaction force of the force acting on the hand 21 of the slave manipulator 20 to the operator operating the handle 11 of the master manipulator 10, a force feedback type pirate system with the best operability as shown in FIG. 4 is used. It is used.

FIG. 4 shows a force feedback type bilateral servo system with one corresponding axis, and each axis of the master manipulator 10 has an actuator 12 . Torque sensor 13. It consists of a load 141 and a position sensor 15, and the slave manipulator 20 also has an actuator 22
, a torque sensor 23, a load 24, and a position sensor 25. The position feedback is a position feedback control loop in which the difference between the output signals of the position sensors 15 and 25 is detected by a comparator 31 and amplified by an amplifier 32 to drive the actuator 22 of the slave manipulator 20. On the other hand, the force feedback control is a force feedback control loop in which the difference between the output signals of the torque sensors 13 and 23 is detected by a comparator 33 and amplified by an amplifier 34 to drive the actuator 12 of the master manipulator 10.

With this configuration, the slave manipulator 20 follows the movement of the master manipulator 1o, and the force applied to the slave manipulator 2o is fed back to the master manipulator 10, thereby allowing the operator to sense the external force applied to the slave manipulator 20. be able to.

As mentioned above, in the master/slave manipulator shown in Fig. 3, the rotation angle and torque of each axis correspond one-to-one, so as shown in Fig. 4, the rotation angle and torque between the corresponding axes are The advantage is that it is sufficient to assemble a lateral servo system, and complex calculation processes such as coordinate conversion are not required. However, there is a constraint that the master manipulator and slave manipulator must have the same axis configuration, so if the slave manipulator has an easy-to-work axis configuration, there is a problem that the operator who operates the master manipulator has poor operability. Therefore, a master/slave manipulator with a different structure has been proposed in which the master manipulator has an axis configuration that is easy for the operator to operate, and the one-way rape manipulator has an axis configuration that is easy to operate, and the two are linked using a computer (I.・E.C.O.N. 84. (1984)
Pages 40 to 45: lEC0N' 84 (198
4)). According to this method, the master manipulator and the slave manipulator can have a free shaft configuration, so that the operability can be improved.

[Problem that the invention seeks to solve]

However, in the case of a master/slave manipulator in which the mask and slave axes have different configurations, as shown in FIG. Coordinate transformation operations must be performed.

That is, for each of the master manipulator 10 and slave manipulator 2o, the rotation angle and torque of each axis are converted into the common coordinate system (XYZ orthogonal coordinates) of the handle 11 and hand 21, and the pirate servo system is converted on the common coordinate system. By combining these, the movements of the handle 11 and the hand 21 are made to correspond one to one. A block diagram of the coordinate transformation of this arithmetic processing unit 40 is shown in FIG.

FIG. 6 shows only the force feedback control loop, and the signal of the torque sensor 13a attached to the shaft near the base of the master manipulator 10 is transmitted to the coordinate transformation unit 16.
At step a, the coordinates are transformed into the coordinate system of the next axis and output to the coordinate transformation unit 16b.

Here, the signal is combined with the signal from the torque sensor 13b attached to the next axis, and then the coordinates are transformed into the coordinate system of the fifth axis.

In this way, coordinate transformation is performed across all axes,
Finally, the coordinate transformation unit 17 transforms the coordinates into common coordinates. On the other hand, regarding the slave manipulator 20, torque sensors 23a, 23b', 23c', 23d
~23f signals are sequentially sent to coordinate conversion units 26a~26
The coordinates are transformed by f, and finally the common coordinate transformation unit 2
7 into common coordinates. The torque sensor signal on the common coordinate system of the master manipulator 10 and slave manipulator 20 obtained in this way is transmitted to the comparator 3
5, the difference is calculated for each corresponding signal, and the difference signal is sequentially converted into the coordinate system of each axis by the inverse coordinate conversion units 18a to 18f, and then transferred to the actuators 12a to 12 of each axis.
f.

In this way, the master/slave manipulator with different structures performs complex coordinate transformation and inverse transformation operations, which increases the time it takes to complete the calculations for each axis, that is, the sampling time.

There is a problem in that the response characteristics of the control system deteriorate, resulting in a poor operational feel.

The purpose of the present invention is to solve the above-mentioned problems, in other words, to significantly reduce the amount of calculation for coordinate transformation, shorten sampling time, and provide a master/slave manipulator with a different structure that has excellent control responsiveness and operability. It is about providing.

[Means for solving problems]

In order to achieve the above object, the present invention provides a centralized axial force sensor that is provided on one axis of a master manipulator and a slave manipulator that have mutually different axis configurations, and detects a plurality of axial force components corresponding to all the constituent axes. The output signals of these two centralized axial force sensors are converted into a predetermined common coordinate system, and the difference signal between the output signals of the two centralized axial force sensors is converted into the coordinate system of each component axis of the master manipulator. and a coordinate inverse transformation means for converting the axial force components into the corresponding axial force components and outputting the corresponding axial force components to the actuator.

[Effect]

With this configuration, the centralized axial force sensor attached to the master manipulator directly detects each axial force component of the force applied by the operator to the handle, which serves as an end effector.

A concentrated axial force sensor attached to the slave manipulator detects each axial component of the external force applied to the hand as the end effector. In this way, the centralized axial force sensor detects the axial force component of each axis corresponding to the constituent axes, so if the centralized axial force sensor is installed on an axis close to the end effector (handle or hand), When converting the axial force component detected by the concentrated axial force sensor to the common coordinate system of the end effector, the number of coordinate conversion processes corresponding to the number of axes interposed between the concentrated force sensor and the end effector is sufficient. Therefore, there is no need to perform coordinate transformation for all the constituent axes, and the amount of coordinate transformation calculations can be significantly reduced, sampling time can be shortened, and control responsiveness and operability are improved.

〔Example〕

The present invention will be explained below based on examples. FIG. 1 shows an overall configuration diagram of a master/slave manipulator according to an embodiment of the present invention, and FIG. 2 shows a block configuration diagram related to a force feedback control loop of an arithmetic processing unit.

As shown in FIG. 1, the wrist arm to which the handle 11 of the master manipulator 1o is directly connected is subjected to forces FXe, FY, Fz, and X, Y in the X, Y, and Z axis directions.

A six-axis force sensor 19 is installed to detect torques τX, τY, and τ2 around the Z-axis, respectively.
In correspondence with the shaft force sensor 19, the wrist arm directly connected to the hand 21 of the slave manipulator 20 also has the same 6
A shaft sensor 29 is attached.

Then, the 6 axis detected by each 6 axis sensor 19, 29
The axial force acid component signals are output from coordinate conversion units 36 and 3, respectively.
7, it is converted into a common coordinate system consisting of XYZ orthogonal coordinate axes. The difference between the axial force signals transformed by the coordinate transformation units 36 and 37 is taken by the comparator 35, and the difference signal is outputted to the inverse coordinate transformation units 188 to 18f in the same manner as explained in FIG. The actuators 12a to 12fci output signals of the respective axes of the master manipulator 10 are outputted sequentially through these inverse coordinate conversion units. As a result, the slave manipulator 20 is moved following the movement of the master manipulator 10, and the force applied to the slave manipulator 20 is detected by the 6-axis force sensor 29, and the axial force detected by the 6-axis force sensor 19 of the master manipulator 10 is detected. The master manipulator 10 is driven according to the difference between
The operator can sense the external force applied to the slave manipulator 20 via the handle 11.

As described above, according to this embodiment, the 6-axis force sensors 19 and 29 that detect the axial force corresponding to the axial configuration of the master manipulator 10 and the slave manipulator 20 are connected to the wrists to which the handle 11 and the hand 21 are directly connected, respectively. Since it is attached to the arm and detects the axial force components of 6 axes applied to each manipulator, it is only necessary to convert the 6 axes into a common coordinate system in one conversion process, and the coordinates The amount of calculations involved in conversion can be significantly reduced. As a result, the sampling time can be shortened, the response characteristics of the manipulator control system can be improved, and the operability can be improved.

Furthermore, when an axial force sensor such as a torque sensor is placed on each axis as in the conventional example shown in FIG. Unnecessary information such as the structure's own weight, inertia, and vibration will be detected.

For this reason, the necessary force applied to the tip of the manipulator could not be detected with high accuracy, and there was a problem in that unnecessary force feedback was applied to the master manipulator, resulting in poor operability. According to the 6-axis force sensors 19 and 29 provided on the wrist arm, information related to the unnecessary manipulator structures mentioned above is not detected, so that highly accurate manipulator control can be performed. This has the effect of improving operability.

In the embodiment shown in FIG. 1, by providing the six-axis force sensors 19 and 29 as centralized axial force sensors on the wrist arm, the conversion process related to coordinate conversion to the common coordinate system can be performed only once. However, the present invention is not limited to this, and includes a device in which a centralized axial force sensor is provided on another arm.

In that case, from the 6-axis force sensor to the end effector (handle,
Needless to say, the number of times the conversion process to the common coordinate system will be performed will be increased depending on the number of axes intervening in the process leading to the hand.

〔Effect of the invention〕

As described above, according to the present invention, the amount of calculation for coordinate transformation can be significantly reduced, sampling time can be shortened, and control responsiveness and operability can be improved.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, and FIG.
3 is a configuration diagram of a conventional example with a coaxial configuration, FIG. 4 is a configuration diagram of a bilateral control system of the conventional example shown in FIG. 3, and FIG. 5 is a configuration diagram of a conventional example with a different structure. FIG. 6 is a block diagram showing the main control block diagram of the conventional example shown in FIG. DESCRIPTION OF SYMBOLS 10... Master manipulator, 20... Slave manipulator, 11... Handle, 12 (12a-12f) - Actuator, 19
...6-axis sensor, 21...hand. 22 (22a to 22f) - actuator,
29...6-axis sensor.

Claims (4)

[Claims] (1) A centralized axial force sensor that is installed on one axis of a master manipulator and a slave manipulator that have different axis configurations and detects multiple axial force components corresponding to all component axes; a coordinate conversion means for converting the output signal of the sensor into a predetermined common coordinate system; and an inverse coordinate conversion means for converting into a coordinate system and outputting each corresponding axial force component to the actuator.
slave manipulator. (2) The master-slave manipulator according to claim 1, wherein the concentrated axial force sensor is provided on a shaft to which an end effector of the manipulator is directly connected. (3) The master/slave manipulator according to claim 2, wherein the end effector of the slave manipulator is a hand. (4) The master/slave manipulator according to claim 2, wherein the end effector of the master manipulator is a handle.