JPH0443740B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Purpose of the Invention [Field of Industrial Application] The present invention relates to a remote control device for a master-slave manipulation system using a master manipulator and a slave manipulator. [Prior art] When workers cannot enter the environment (work environment) to perform the actual work, such as work in space, the ocean, or the nuclear field,
Usually, a method is used in which a slave manipulator is installed in a work environment, and this is remotely controlled using a master manipulator installed in a safe remote operation environment. In order to improve the maneuverability of this master-slave manipulation system and perform remote control smoothly, it is necessary to accurately transmit information in the work environment to the operator in the operating environment. It is desirable to reproduce the displacement and applied force state as faithfully as possible on the master manipulator side. For this reason, attempts have been made to transfer the force and torque applied to the slave manipulator to the master manipulator, and various bilateral servo mechanisms have been proposed to meet this purpose. . One of these bilateral servo mechanisms is a force feedback type bilateral servo mechanism as shown in FIG. In this bilateral servo mechanism 101, a position servo system is configured on the slave manipulator 103 side, and when the displacement on the master manipulator 102 side is detected by the position detector 104, the output is used as a command signal to control the slave manipulator 103. Manipulator 10
The position servo system 105 on the third side works, and the slave manipulator 103 becomes the master manipulator 102.
It moves according to the displacement of. On the other hand, if some kind of restraint force is applied to the slave manipulator 103 from the object at this time, it is detected by the torque (or force) detector 106 and transmitted to the master manipulator 102 side. . A torque servo system 108 consisting of a drive motor (not shown) and a torque (or force) detector 107 is configured on the master manipulator 102 side, and the torque detector 106 detected by the slave manipulator 103 By applying an output signal to this torque servo system 108, a torque equivalent to the torque applied to the slave manipulator 103 is generated on the master manipulator 102 side. [Problems to be Solved by the Invention] By the way, in this type of bilateral servo, the force is sent back from the slave manipulator side to the master manipulator side, but as described above, the force is sent back to the slave manipulator 103 side. This is done by the installed torque detector 106 and the torque servo system 108 installed on the master manipulator 102 side, but since there are generally various delays in the torque servo system, it is detected on the slave manipulator side. Torque is not necessarily accurately transmitted to the master manipulator. That is, this is because a tracking error occurs in the torque servo system. When the torque detected on the slave manipulator side fluctuates at a high speed, this follow-up error becomes a non-negligible amount, making it impossible to provide a sense of realism to the operator. This invention has been made in view of the above circumstances, and it is an object of the present invention to feed back the entire dynamic compliance including the constraint conditions on the slave manipulator side to the drive system on the master slave side in a master-slave type manipulator. By realizing a restraint state on the master manipulator side that is equivalent to that on the slave manipulator side, it is possible to perform remote control with a realistic feeling of remote control, allowing the operator to more directly manipulate the object. The object of the present invention is to provide a remote control device that allows the user to feel as if he or she is actually in the room and can control the sense of realism. (C) Structure of the Invention [Means for Solving the Problem] Corresponding to this object, the dynamic compliance reverse feed type bilateral remote control device of the present invention has a master manipulator that acts on the master manipulator. a first force detector that detects the force exerted by the slave manipulator; and a first position detector that detects the position of the master manipulator; the slave manipulator that handles the object detects the position of the slave manipulator; a second position detector for detecting the force acting on the slave manipulator and a second force detector for detecting the force acting on the slave manipulator; The slave manipulator is equipped with a dynamic characteristic identifier that determines an element of the dynamic characteristic of the object from the force signal, and adjusts the dynamic compliance of the master manipulator according to the element of the dynamic characteristic. It is characterized by being configured so that the mechanical restraints applied to it are reversed. DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, details of the present invention will be explained with reference to the drawings showing one embodiment. In FIG. 1, 1 is a master/slave manipulator control device, and the master/slave manipulator control device 1 includes a master manipulator mechanism 2, a slave manipulator mechanism 3, and a transmission system 4. . Master manipulator mechanism 2
are a master manipulator 5, a master manipulator drive device 6 that drives the master manipulator 5, a position detector 7 that detects the position of the master manipulator 5, and a position detector 7 that detects the force acting on the master manipulator 5. An amplifier 11 for amplifying input signals to the force detector 8 and the master manipulator drive device 6
It is equipped with On the other hand, the slave manipulator mechanism 3 includes a slave manipulator 13, a slave manipulator drive device 14 that drives the slave manipulator 13, a position detector 15 that detects the position of the slave manipulator 13, and a slave manipulator 13 that drives the slave manipulator 13. A force detector 16 that detects the force acting on the manipulator 13
and an amplifier 17 for amplifying the input signal to the slave manipulator driving device 14. The master manipulator mechanism 2 and slave manipulator mechanism 3 are connected via a transmission system 4. The transmission system 4 includes a dynamic characteristic determiner 18, a position signal generator 21, a dynamic specific compensator 22, and two comparators 23,
It is equipped with 24. [Operation] The ideal of bilateral control can be rearranged as follows. In other words, as shown in Fig. 2, when a certain displacement Δx is applied to the master manipulator side, an accurate displacement Δx is applied to the slave manipulator.
If this occurs, and at that time the slave manipulator applies some kind of symmetrical action and receives a reaction force of ΔF, then that ΔF is accurately transferred to the master manipulator and the master manipulator It is the right thing to do to the operator who operates the . At this time, in FIG. 2, it is assumed that Δx is applied on the master manipulator side, but it may be thought that Δx can be accurately transferred by applying a force of ΔF on the contrary. To give another example, consider a case where an object 112 is manipulated via a rigid rod 111, as shown in FIG. In such a rod 111, when a displacement of Δx is applied to the operating end, Δx is similarly applied to the working end. Then, when the reaction force ΔF is applied to the operating end, it is transmitted to the operating end. In other words, the mechanical state of the operating end (Δx, ΔF) and the mechanical state of the working end (Δx, ΔF)
are the same (if the rod is completely rigid).
Such a transmission system is ideal, and in master-slave manipulator control, even if the system is not physically integrated, the mechanical state of the master manipulator and slave manipulator can be controlled in some way. Various attempts have been made to bring these into agreement. The relationship between the displacement Δx at the working end and the reaction force ΔF generally changes depending on the characteristics of the object to be operated. If the object is soft, ΔF will be small even if a large Δx is applied, and if it is hard, a large ΔF will occur even with a small Δx. Also, since Δx and ΔF change over time, for example, Δx and ΔF at the working end,
ΔF can be represented by a graph as shown in FIG. After all, as described above, the ideal purpose of the master/slave manipulator is to accurately reproduce the states of ΔF and Δx at the operating end, and the present invention relates to this. That is, it is ideal that the mechanical state (Δx, ΔF) on the master manipulator side and the mechanical state (Δx, ΔF) on the slave manipulator side match. Incidentally, the relationship between ΔF and Δx at the working end on the slave manipulator side can be described by the dynamic characteristics of the object. That is, the mechanical properties of an object generally include an inertial element J, a viscous element γ, a spring element k, and a proportional element K, and using these, the relationship between ΔF and Δx can be expressed by the following differential equation. It can be written as JΔx¨+γΔx・+kΔx=KΔF Therefore, in the master-slave manipulator mechanism, an equation describing the relationship between Δx and ΔF like this is identified depending on the object, and a system with the same mechanical structure is That is, a system that generates ΔF when the operator adds Δx or a system that generates Δx when the operator adds ΔF can be configured as a master manipulator mechanism. In the present invention, as described above, the master manipulator mechanism and the slave manipulator mechanism have similar structures, and the master manipulator has a force sensor 8,
Master manipulator drive device 6, position sensor 7
A force sensor 16, a slave manipulator driving device 14, and a position sensor 15 are also installed on the slave manipulator.
When the operator operates the master manipulator 5, the master manipulator drive device 6 moves, the position at that time is detected by the position detector 7, and the position signal becomes a command signal to the slave manipulator mechanism 3. . On the other hand, the slave manipulator mechanism 3 includes a position servo system, and the slave manipulator 13 operates in response to the above-mentioned position command signal from the master manipulator mechanism 2. When the slave manipulator 13 applies an action to the object 25, the displacement and the reaction force coming from the object 25 at that time are detected by the force detector 16 and applied to the dynamic characteristic identifier 18. This dynamic characteristic identifier 18 is a device for determining the parameters J, γ, k, and K of the above-mentioned differential equation, and the method for determining the parameters can be performed using conventional techniques. That is, if the characteristics (J, γ, K, k), displacement Δx, and force ΔF of the object 25 are expressed as JΔx+γΔx·+kΔx=KΔF, they can be easily determined by this dynamic characteristic identifier 18. This parameter is then transferred to the master manipulator mechanism 2 side. On the master manipulator mechanism 2 side, the characteristics of its drive system are determined to be the same as the characteristics of the slave manipulator mechanism 3. In short, when the operator applies a force ΔF to the master manipulator 5 as a control operation, a displacement Δx is generated in the master manipulator mechanism 2. That is, so that the force ΔF and displacement Δx of the master manipulator 5 can be written in the differential equation JΔx¨+γΔx・+kΔx=KΔF, which is the same as the differential equation that relates the force ΔF and displacement Δx of the slave manipulator mechanism 3. The characteristics of the servo mechanism on the master manipulator mechanism 2 side are determined. The servo system on the slave manipulator side shown in FIG. 1 is configured to realize this. To make the explanation easier, the parts A and B in FIG. 1 are extracted and drawn as shown in FIG. 5. That is, the force ΔF applied by the operator to the master manipulator 5 from point A in FIG. 5 is detected by the force detector 8,
The position signal generator 21 determines Δx corresponding to ΔF. This calculation is performed by solving JΔx¨+γΔx·+kΔx=KΔF using a microcomputer or the like. At this time, J, γ, k, K are dynamic characteristic identifier 18
Use the value determined in Δx thus determined is input to the position servo system of the master manipulator mechanism 2. The servo system of the master manipulator mechanism 2 needs to have a transfer characteristic between point A and point B of 1 in order to ensure that the transfer characteristic between point A and point B is accurately described by the above differential equation. There is. A dynamic characteristic compensator 22 is added for this purpose. This method of addition can be easily realized using conventional techniques. In this way, a bilateral mechanism can be constructed in which the relationship (Δx, ΔF) on the slave manipulator mechanism 3 side is accurately transferred back to the master manipulator mechanism 2 side. FIG. 6 shows an extension of the above-described principle of the present invention to an n-degree-of-freedom system. As shown in FIG. 7a, for example, when a master manipulator turns a crank, the manipulator is constrained to some extent by the crank. This restraint can generally be schematically represented as a restraint having a mechanical structure consisting of inertia, viscosity, and elasticity in three orthogonal axes directions of the hand of the manipulator, as shown in FIG. 7b. This mechanical structure can be evaluated as the dynamic characteristics G ₁ to _{G o} of each joint by attaching a torque detector and a position detector to the joints of the manipulator from their combined output (τ _i , θ _i ). That is, the dynamic characteristics of the restraints regarding the orthogonal axes of the hand are G _x , G _y , G _z , M _x , My _y , M _z , and the number of joints is 6, and the dynamic characteristics of each joint are G ₁ to G ₆ , G _x ...and
Let K→ be the matrix that relates G ₁ ..., then G ₁ G ₂ G ₃ G ₄ G ₅ G ₆ = K→ G _x G _y G _z M _x M _y M _z Thus obtained, G ₁ G ₂ G ₃ G ₄ G ₅ G ₆ can be realized as the characteristics of the servo system on the master manipulator mechanism side. Here, G ₁ to _{G 6} are measured by the joint dynamic compliance identifier shown in the figure. G ₁ to _{G 6} are differential equations that relate the angular displacement Δθ _i and the torque τ _i in the slave joint axis. Using the normal Laplace transform representation, Δθ _i and τ _i are written as follows.

[Table] 〓Δθ ₆ 〓 〓0 0 0 0 0 G ₆ 〓〓〓τ ₆ 〓
In order to provide this characteristic to the servo system on the master manipulator mechanism side, a trust signal generator is used.

[Table] 〓0 0 0 0 0 G ₆ 〓〓τ ₆ 〓
Calculate Δθ ₁ ...Δθ ₆ and input them to the position servo system. The master manipulator mechanism has a motor, force sensor, and position/angle sensor on each axis.
It operates by following Δθ ₁ ...Δθ ₆ . At this time, in order to make the dynamic characteristics of the master servo system match _G1 ... _G6 , it is necessary to set the characteristics of the position servo system to 1.
For this purpose, characteristic compensation is added as in the case of one degree of freedom. The slave manipulator and master manipulator do not necessarily have to have similar structures. However, the number of degrees of freedom (number of joints) must match. When the structures of the slave manipulator and master manipulator are different, coordinate transformation is required when transmitting information between the master manipulator and slave manipulator. This coordinate transformation can be realized using conventional techniques. This coordinate transformation is also shown in the embodiment shown in FIG. (C) Effects of the Invention As described above, according to the present invention, in a master-slave type manipulator, by feeding back the entire dynamic compliance including the constraint conditions on the slave manipulator side to the drive system on the master side, By creating a restraint state on the master manipulator side that is equivalent to that on the slave manipulator side, the operator can feel as if he or she is manipulating the object more directly, creating a sense of realism. A remote control device can be obtained that allows some control.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the configuration of a remote control device according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the dynamic state of the master manipulator side and the slave manipulator side, and FIG. An explanatory diagram showing another example of the mechanical state of the manipulator side and the slave manipulator side, Fig. 4 is a graph illustrating the time change of reaction force and displacement, and Fig. 5 is the remote control shown in Fig. 1. FIG. 6 is a configuration explanatory diagram showing a remote control device according to another embodiment of the present invention, FIG. 7 is a perspective explanatory diagram showing a restrained state to which a slave manipulator is subjected, and FIG. 8 is a conventional diagram. FIG. 2 is a configuration explanatory diagram showing a force feedback type bilateral control mechanism. 1... Master manipulator control device, 2... Master manipulator mechanism, 3... Slave manipulator mechanism, 4... Transmission system, 5... Master manipulator, 6... Master manipulator drive device, 7... Position detection device, 8...force detector, 11...amplifier, 12
...Compliance adjustment device, 13...Slave manipulator, 14...Slave manipulator drive device, 15...Position detector, 16...Force detector, 1
7... Amplifier, 18... Dynamic characteristic identifier, 21... Position signal generator, 22... Dynamic characteristic compensator, 23... Comparator,
24...Comparator, 25...Object.

Claims (1)

[Claims] 1 A first force detector that detects a force acting on the master manipulator, and a first force detector that detects the position of the master manipulator.
a second position detector for detecting the position of the slave manipulator and a second force for detecting the force acting on the slave manipulator; a dynamic characteristic identifier for determining an element of the dynamic characteristic of the object from the position signal from the second position detector and the force signal from the second force detector; A dynamic compliance reversal type bike characterized in that the mechanical restraint applied to the slave manipulator is reversed by adjusting the dynamic compliance of the master manipulator by the elements of Lateral remote control device.