JPH0442145B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a motion restriction device for a master-slave manipulator having a different structure, which is effective for work in environments dangerous to humans.

Here, the master arm and slave manipulator that have mechanically similar structures are defined as "same structures," whereas those that have dissimilar structures and therefore the joint coordinate system Anything that is different is defined as "different structure." For example, a mechanism in which the hand has six degrees of freedom in position and direction is
It can be realized using various mechanisms such as a humanoid multi-jointed structure, polar coordinates, cylindrical coordinates, or rectangular coordinates, or variations thereof, but the above-mentioned "different structures" are different from these mechanisms. .

[Prior Art] Generally, in a master-slave manipulator, the master arm and slave manipulator have the same structure in order to simplify control.
In this case, since the master arm is restricted to the same structure as the slave manipulator, there are problems such as poor operability in some cases. It is effective to use a different structure from the viewpoint of operability.

When configuring a master-slave manipulator system with such a different structure, information such as the position, velocity, and force of the master arm and slave manipulator must be transformed between the joint coordinate systems of both. Each joint coordinate system has its own specific hand movement range, and problems caused by differences in this movement range become a problem.

More specifically, as illustrated in FIGS. 1A to 1C, the fingers of the articulated manipulator M ₁ , the polar coordinate manipulator M ₂ , and the orthogonal coordinate manipulator M ₃ are A ₁ , A ₂ , and A , respectively. ₃ , if the master arm and slave manipulator with these structures are appropriately combined to form a master slave manipulator system with different structures, it is possible to create a master slave manipulator system with different structures because each manipulator has a different range of movement. , Figure 2 A~
It cannot be operated unless it is within the common movable range A ₀ shown in C, and if the master arm gives a motion command beyond the movable range of the slave manipulator, it may damage the device or This may pose a danger to the operator.

Note that Figure 2A shows the common range of motion for articulated and polar coordinate manipulators, Figure 2B shows the common range of motion for articulated and Cartesian manipulators, and Figure C shows the common range of motion for polar and Cartesian manipulators. Shows common range of motion.

[Problems to be Solved by the Invention] The technical problem of the present invention is to solve such problems in master slave manipulators with different structures, and to solve the problems in master arm and slave manipulators having arbitrary joint structures. The purpose is to prevent troubles due to differences in operating areas and facilitate operator operations.

[Means for Solving the Problems] In order to solve the above problems, the manipulator movement limiting device of the present invention includes a master arm having a different structure from each other and a slave manipulator driven by the master arm, and connects them to a coordinate converter. A master-slave system with a different structure that transforms joint coordinate systems and transmits information by connecting via
The manipulator is constructed by providing a motion limit indicating device for feeding back to the operator when either the master arm or the slave manipulator reaches the limit of its movable range.

[Function] According to the manipulator movement restriction device of the present invention, when the master arm is operated,
The position information detected by the position detector on the master side is converted from the joint coordinate system of the master arm to the joint coordinate system of the slave manipulator in the position coordinate converter, and the converted position information is used as a command value to convert the position information on the slave side. Drive the actuator.

Therefore, the hand of the slave manipulator follows the hand of the master arm and makes the same movement.

On the other hand, the force information detected by the force sensor on the slave side is converted from the joint coordinate system of the slave manipulator to the joint coordinate system of the master arm in a force coordinate converter, and the converted force information signal is sent to the actuator on the master side. Generate driving force. Therefore, when a reaction force is generated at the tip of the slave manipulator due to interference with an object, the reaction force is transmitted to the master arm.

In the master-slave system mentioned above, there is a difference in the movable range between the master arm and the slave manipulator, which have different structures.In order to prevent troubles caused by this difference, the movement limit indicating device is installed to prevent the master arm from occurring. , when the master side and the slave side are driven beyond the common movable range, it is temporarily stopped and forced to return to the standard state. Therefore, the operator does not have to be careful about the operating limits, and the master arm can be easily operated.

[Embodiment] FIG. 3 shows an embodiment of the manipulator motion restriction device according to the present invention, in which the master arm 1
As the slave manipulator 2, various structures can be freely selected and used.

Master arm 1 and slave arm shown in Figure 3.
The manipulator 2 schematically shows the configuration of each joint therein, and 11 and 21 are actuators such as motors that generate driving force on each axis in the joint;
12 and 22 are position detectors such as potentiometers,
Numerals 13 and 23 are torque sensors and other force sensors for detecting reaction force, and numerals 14 and 24 are speed detectors such as tachogenerators. The master arm and the slave manipulator each have n joints, where n is their degree of freedom, and therefore n actuators and various sensors are each installed.

Since the master arm 1 and slave manipulator 2 have different joint structures, it is necessary to perform coordinate transformation between their joint coordinate systems. The two are connected via a position coordinate converter 5, a force coordinate converter 6, and a velocity coordinate converter 7. Each of these coordinate transformers performs coordinate transformation operations between the master arm and the slave manipulator.
It is composed of arithmetic devices such as computers.

Then, the position information P ^m detected by the position detector 12 on the master side is converted from the joint coordinate system of the master arm 1 to the slave slave by the position coordinate converter 5.
The converted position information P ^{m is converted into the joint coordinate system of the manipulator 2, and is compared with the position information P s detected} by the position detector 22 on the slave side as a command value. 31 to drive the actuator 21 on the slave side.

Therefore, the hand of the slave manipulator 2 follows the hand of the master arm 1 and makes the same movement.

On the other hand, in order to feed back the force information ^Fs detected by the force sensor 23 on the slave side to the master side, the output of the force sensor 23 is transferred from the joint coordinate system of the slave manipulator 2 to the joint coordinate system of the master arm 1 in the force coordinate converter 6. The force sensor 13 on the master side converts the converted force information ^Fs into a coordinate system.
The force controller 32 generates a driving force in the actuator 11 on the master side using the difference between the force information F ^m and the force information F m detected by the force controller 32 . Therefore, when a reaction force is generated at the tip of the slave manipulator 2 due to interference with an object, the reaction force is transmitted to the master arm.

Furthermore, in order to improve the response of the above control, the following speed control is performed. That is, the coordinate system of the speed information V ^m detected by the speed detector 14 on the master side is converted into the joint coordinate system of the slave manipulator 2 by the speed coordinate converter 7, and this is converted by the speed detector 24 on the slave side. The actuator 21 is then driven via the position controller 31 using the difference between the detected velocity information V ^s and the detected velocity information V s .

In the master arm 1, in order to perform force control, speed information from the speed detector 14 on the master side is fed back to the actuator 11 via the force controller 32.

In the above-mentioned master-slave manipulator system, an operation limit indicating device is attached in order to solve the problem of troubles caused by the difference in the movable range between the master arm and the slave manipulator, which have different structures. The motion limit indicating device in the embodiment shown in FIG. 3 temporarily stops the master arm 1 when it is driven beyond the movable range common to the master side and the slave side, that is, beyond the given motion range. It is designed to return to the standard state. The above-mentioned reference state means a state in which the master arm is approximately at the center of its movable range, or a state in which it is at an initial setting position. Therefore, as the above-mentioned movement restriction device,
Specifically, the reference state return circuit 41 includes a built-in storage device that stores a movable range, that is, an operation area common to the master side and the slave side, and the reference state return circuit 41 stores the positions of the master side and the slave side. It is determined whether the position information from the detectors 12, 22 is within the above-mentioned operating range, and if it is determined that the position information is outside the operating range, the actuators 11, 21 on the master side and slave side are immediately activated. It can be configured to output a signal for temporarily stopping the master arm 1 and the slave manipulator 2, and then output a signal for returning the master arm 1 and slave manipulator 2 to their reference states.

The operating limit indicating device in the embodiment of FIG.
Operation display device 42 including a monitor display, etc.
, the position detector 12 on the master side and the slave side,
The operation display device 42 displays the operation area on a monitor display and also connects to the position detectors 12, 2.
The hand positions of the master arm 1 and the slave manipulator in the operating area are displayed based on the output of the master arm 1 and the slave manipulator 2.

Therefore, when the operator operates the master arm 1 while looking at the monitor display on the operation display device 42, it is possible to prevent the master arm 1 from moving out of the operating range.

Note that the other configurations are the same as the embodiment shown in FIG. 3, so the same or corresponding parts are given the same reference numerals and their explanation will be omitted.

The operating limit indicating device in the embodiment shown in FIG. 5 is constructed by attaching operating range limiting circuits 43 and 44 to the master arm 1 and the slave manipulator 2, respectively, so that either the master arm or the slave manipulator 2 When the limit of the operating range is reached, a force is generated in the master arm to return it to the operating range.

That is, the limiting circuit 43 attached to the master arm 1 compares the limit value P ^m _L of a predetermined operating region with the position information P ^m output from the position detector 12 for position detection, and determines the difference. An output corresponding to is inputted to the function generating element 45, and when the input reaches a certain set value, a constant output is generated, and the output operates the actuator 11 on the master side via the force controller 32. This generates a force for returning the master arm 1 to the operating range when it reaches the limit of its operating range.

Further, the limiting circuit 44 attached to the slave manipulator 2 outputs an output corresponding to the difference between the limit value P ^s _L of a predetermined operating region and the position information P ^s from the position detector 22 to the function generating element 46 . When the input reaches a certain set value, a certain output is generated, and the output is added to the force information ^Fs detected by the force sensor 23 as return force information and fed back to the master side. When the slave manipulator 2 reaches the limit of its operating range, it generates a force for returning the master arm 1 to the operating range.

Therefore, when either the master arm 1 or the slave manipulator 2 reaches the limit of its operating range, a force is generated to return the master arm 1 to the common operating range.

Note that the other configurations are the same as those of the embodiment shown in FIG. 3, and therefore the same reference numerals as in FIG. 3 are given.

[Effects of the Invention] According to the manipulator motion restriction device of the present invention detailed above, when performing coordinate transformation between a master arm having an arbitrary joint structure and a slave manipulator, mechanically any slave manipulator can be・You can select and use a manipulator, and at the same time, you can adopt any mechanical master arm and freely combine them without being limited by the mechanism of the slave manipulator. In that case, the master arm Or, when one of the slave manipulators reaches the limit of its movable range, it is fed back to the operator, which prevents troubles such as malfunctions due to differences in the movable ranges of the master arm and slave manipulator. be able to.

That is, it is possible to solve the above-mentioned disadvantages caused by the difference in the operating range of the master arm and the slave manipulator, which is a problem inherent in master-slave systems with different structures, and the operator has to constantly pay attention to the operation of the slave manipulator. There is no need to operate the master arm so that it does not exceed the operating range, and the operator is freed from excessive attention, so the operator can concentrate on the work and improve the work efficiency.

[Brief explanation of the drawing]

Figures 1A to C are explanatory diagrams of the movable range of the manipulator, Figures 2A to C are explanatory diagrams of the operational range of a master-slave manipulator that combines the above manipulators, and Figures 3 to 5 are diagrams of the present invention. FIG. 2 is a schematic configuration diagram of an embodiment of the present invention. 1... Master arm, 2... Slave manipulator, 5... Position coordinate converter, 6... Force coordinate converter,
7... Speed coordinate converter, 11, 21... Actuator, 12, 22... Position detector, 13, 23... Force sensor, 14, 24... Speed detector, 41... Reference state return circuit, 42... Operation display device, 43 , 44...limiting circuit.

Claims (1)

[Claims] 1 Equipped with a master arm having a different structure and a slave manipulator driven by the master arm,
In a master-slave manipulator with a different structure in which joint coordinate systems are transformed and information is transmitted by connecting them via a coordinate converter, either the master arm or the slave manipulator has a movable range. A motion limiting device for a master-slave manipulator with a different structure, characterized in that a motion limit indicating device is provided to provide feedback to an operator when the limit is reached.