JPS5959389A - Robot - 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 (1) Technical Field of the Invention The present invention relates to an industrial robot, and more particularly to a robot equipped with a manual attachment and having a congratulatory mechanism at the connection between its arm and hand. It is.

(2) Background of the technology With the advent of industrial robots, automatic silk erecting has progressed, and the work involved is becoming more precise and faster. According to this i'+, it is necessary to improve the precision of the robot's positioning. However, it is often difficult to produce high-precision Japanese text simply by improving the precision of the robot. Because the relative positional relationship of
In addition to absolute positioning, this relative position must be determined frequently.

Particularly in the fitting work on the order of several micrometers, consideration must be given to the problem of positioning the relative position with such high precision.

(3) Conventional technology and problems High-precision mating by robots: In order to perform mating work smoothly, the hand is changed relative to the arm using a compliance mechanism consisting of a plate spring or coil spring (V'E
] A wrist structure has been proposed that absorbs misalignment in the relative positions of objects to be assembled.

However, in such a wrist structure, if the compliance is increased in an attempt to increase the ability to absorb relative positional deviation, the force in the insertion direction during the fitting operation will also be weakened, making it difficult to obtain an appropriate insertion force and making insertion difficult. Also, if the wrist part has a large degree of compliance, large vibrations σjj will occur when starting and stopping when transporting the insert, which will impede speed.

(4) Purpose of the Invention The present invention has been made in view of the point P in the prior art. Reduce compliance to prevent vibration during transportation,
The purpose of the present invention is to propose a robot with variable conformance so that smooth insertion can be achieved by increasing the compliance in the direction of displacement of the C position during insertion work.

(5) Structure of the Invention In order to achieve this object, the present invention provides a robot consisting of a hand for grasping an object and an arm for moving the hand. A wrist made of a compliance mechanism is provided, and a wrist drive mechanism is provided for moving the wrist in forward and reverse directions in response to the above-mentioned displacement, thereby making the compliance variable.

(6) Embodiment of the Invention Figures 1 and 2 are perspective views of the wrist of a robot according to the present invention viewed from above and below, respectively. The upper surface of the parallel spring net 2 is fixed to a wrist support plate 1 that is joined to an arm (not shown). This parallel spring assembly 2 is displaceable in the X direction and the Y direction perpendicular to the bias force, and has two parallel plate springs 3. Not hand mounted. When the relative position of the insertion object and the insertion hole is not correct during robot fitting operation, the X-direction component of the reaction force of the insertion pressure.

Each of the parallel plate springs 3 and 4 deforms in accordance with the Y-direction component and shifts in the X- and Y-directions to absorb this positional deviation and achieve insertion. A strain cage 9-5 is attached to each of the parallel plate springs 3, 4 to detect the amount of deformation thereof. The strain gauge 5 is attached to the position where the amount of deformation of the parallel plate spring is maximum, that is, to the upper end or lower end of each parallel plate spring. Depending on the output of this strain gauge 5, the deformation of each flat stone plate spring 3, 4 is divided by
The displacement in the direction and Y direction is detected. A flat plate coil 6 for driving in the X direction and a flat coil 7 for driving in the Y direction are connected to the connecting rod 9 at the lower part of the parallel spring string body 2, and each striking surface coil 6.7 is magnetically coupled by a yoke 21. It is placed between the upper and lower permanent magnets 8. These flat top) coils6.
7 and X by permanent magnet 8.

A planar flow motion switch that can move in the Y direction is constructed.

When force is applied only in the X direction of the spring string body 2, the output and pressure of the aforementioned strain case 5 in the X and Y directions are calculated as follows.
As shown in the figure. As can be seen from this figure, there is little mutual interference in the X and Y directions, and the linearity of force/displacement/output is good. Therefore, based on the output of each strain sensor 5 in the X direction and the Y direction, the flat 1 pJ coil 6.
7 can be driven and controlled independently, and as a result of these movements, the lower part of the parallel spring assembly 2 can be moved to the desired position 771 to make the compliance variable. For example, when the parallel spring assembly is displaced in the X direction, the above-mentioned electric drive control (f The shikonzoliance is thick and shaky.On the contrary, if the parallel spring assembly is changed (18, flow is applied to the plane coil so that it moves in the Y direction and the free direction, the compliance becomes smaller.

The surface pressure and equation of motion of such a planar DC motor are as follows.

However, V: resistance between the terminals of the motor, pressure R: resistance between the terminals of the motor i: N, current of the motor L: @, motor inductance B: %, motor air gap magnetic flux density t: effective coil length of the electric plate M: moving part Mass β: Viscous damping coefficient: Spring constant of parallel spring X: Displacement of parallel spring is 2 hours. This can be expressed in a block diagram as shown in Figure 4. FIG. 5 shows a block diagram of a trust feedback control configuration in which the transfer position X is fed back to this system via the gain A1, and the 6th part is fed back in the normal flow. 9 in Figure 5
The internal transfer function A2 is calculated as follows.

Here, if the part Am is made into a circuit coffin as shown in Fig. 6, then Am
−■ can be approximated as υ, so E(s) −A f I (s)
(4) and 餉j can be expressed in a simple form. That is, the severity of the current rise due to the inductance L can be ignored. Sasa is
The closed roof zero transfer function G(s) is as follows. The condition that formula (6) is stable is k −1-AlA2 Bt) 0 (7). Equation (7) represents fd stiffness. Here A2
= 1 (V/A), it means that by using equation (7), the compliance Cm of the parallel spring support system can be stably changed to 0 (Cm (■ b) within the range. In other words, A1 or O<A+ <ω becomes 0(Cm('. Therefore, A1
When is negative, the parallel spring is soft, and when is positive, it is hard. Compliance can be set arbitrarily by changing A and A2 as described above.

In FIG. 6, F indicates a motor equivalent circuit, and R1 indicates a current detection resistor. Sword, Am, and Af are dyne.

In order to change compliance in this way,
As shown in Figure 7, the code switching of feedback key A is performed by the central control unit (CPU), which determines the robot's work status, such as transportation work or assembly work, and optimizes the compliance of the parallel springs accordingly. The code control signal A is configured to be sent so that the code control signal A is transmitted.

A concrete example of such a circuit is shown in FIG. G is a flat rectangular 1 internal current current rod, and 13 is a transfer type j analog switch in which 0N10FF is activated alternately.

The analog switch 13 is controlled by No. 48 from the CPU, and the displacement of the parallel spring 2 causes the position A from the strain cage 5 to be changed to the (+) fl or (-) of the 7" 22.
fllll, and thereby the bid feedback key/A
The sign of I can be (+) or (-).

FIG. 9 shows another example of the variable circuit according to the present invention. In this example, 1. The positive feedback is the positive feedback of the position of the force U from the strain cage based on the φ position of the spring, and the negative feedback is the negative feedback. The low frequency region of the differential term (mouth y
l? Keyne A1 (Tsukudashiro with slow throat movements)
In order not to cancel the difference, the mountain flow term is given positive feedback. FIG. 10 shows the Paude string diagram of the differential term, and FIG. 11 shows the Bode diagram of the integral term. As for the differential term, since the key increases from 1/2πT2H7, the amount of negative feedback of the position also increases, and the compliance of the system becomes slightly harder than the parallel spring. (See the integral term): ll', 1/2πT3 to 1/2π
Since the key decreases toward T2, the compliance decreases to the spring compliance 1/kh side.

The circuit of FIG. 9 introduces the characteristics of a combination of such key flaws in the differential and integral terms, and FIG. 12 shows a graph representing compliance. (1
) When the eyebrow wave number fz≦1/2πT3, when A2kk/B7 is used, the compliance CCm1tC becomes ω,
(ll) 1/2 rc T3 <fz≦1/2π
At T2, it changes in the range 1/k<Cm<", and Gj
l) 1/2πT2 (0 (Cm
(It changes in a range of 1/2.) In this way, the compliance can be changed so that the parallel spring becomes stiffer when the robot moves rapidly, and becomes softer when the robot moves slowly.

FIG. 13 is a perspective view of another example of the compliance mechanism that constitutes the wrist of the robot according to the present invention. In this example, a parallel spring assembly 2 similar to the previous example is combined with a cruciform leaf spring 14. Which cruciform plate pie 14 allows the connecting rod 9 connected to the cruciform plate spring 14 to swing around the X-direction axis and Y-direction axis on the same plane as the cruciform leaf spring 14,
When performing a fitting operation with the hand deviating from the arm in the correct direction (t?l angle) and the insertion shaft (the hook of the fastening rod 9) being sacral to the hole to be inserted. This angle deviation is absorbed to achieve JI entry.In order to make the compliance of such a compliance cup variable,
m141g1 and as shown in FIG. The planar DC frost and motive for varying the compliance are arranged one on top of the other.The plane direct current and motive for tilting the shaft are connected to the Franz source 115 in the middle of the connecting rod 9, and are driven in the X direction in the same way as in the previous example. It is constructed by fixing the support plate 16 of the planar coil 17 (only one shown in FIG. 1) for 1tJI and Y direction drive, and placing permanent magnets 8 above and below it. By driving, the connecting rod 9 can be tilted in any desired direction around the connection point 1 with the cross spring, and the compliance against axis tilting can be made variable in the same way as in the previous case. The strain gauge 5, which detects the displacement of the cross spring and controls the drive of the motor based on this, is attached near the center of the cross where the cross spring is largely deformed.This motor drive control method is based on the previous example. The same is true for .

(7) As explained in detail, in the present invention, since the variable compliance mechanism is attached to the robot's wrist, it is possible to achieve appropriate compliance according to the work content, and compared to the insertion and assembly of lightweight members. It is possible to smoothly insert and assemble the targeted part without using a high-precision positioning device. In addition, when there is sudden movement such as when transporting military equipment, strain gauges can detect this as a large displacement due to high frequency vibration, and in response, the compliance can be reduced and the spring made stiffer. When there is gentle movement such as during assembly work, the strain cage is used to calibrate this as a small displacement due to low frequency vibration, and correspondingly the compliance can be increased to make the spring softer. Therefore, it is possible to achieve a smooth fitting fit and a high speed of operation.

[Brief explanation of the drawing]

1 and 2 are perspective views of the upper and lower wrist forces of the robot according to the present invention, and FIG. 4 and 5 are block circuit diagrams of robot control according to the present invention, FIG. 6 is a partial circuit diagram showing a part of the block diagram of FIG. 5, and FIGS. 7 and 8 are robot control diagrams according to the present invention. Another block diagram 1 and circuit diagram of control, FIG. 9 is still another block diagram of robot control according to the present invention, and FIGS. A differential term, an integral term, and a key characteristic diagram of their composition; FIG. 13 is a perspective view of another example of the compliance mechanism according to the present invention;
4 and 15 are a sectional view and a perspective view, respectively, of the wrist of a robot according to the present invention using the compliance machine width of FIG. 13. 2... Parallel spring assembly, 5... Strain cage, 6, 7.
...Flat Koinope 8...Permanent magnet, 9...Connecting rod, 1
4...Cross shaped leaf spring. Applicant: Fujitsu Limited Injury Patent Attorney: Akira Aoki, Patent Attorney, Kazuyuki Nishidate, Patent Attorney: 1) Patent Attorney: Akiyuki Deguchi, Figure 1, Figure 2, Figure 3, 1.1. 1 Figure 4 Figure 6 (C:PU) @ Figure 8 PU Figure 9 Figure 10 Figure 11 Figure 4'1' Figure 12 So, 1 Figure 14

Claims (1)

[Scope of Claims] 1. In a robot consisting of a hand for controlling an object and an arm for moving the hand, there is a modification of the hand to the arm for connecting the hand and the arm.
A compliance mechanism for controlling kP is provided, and a wrist is provided for moving the wrist in the forward and reverse directions in response to the above-mentioned displacement, thereby making the compliance variable. O-bond that uses it as a planter. 2. In the robot according to claim 1, a coil or a magnet constituting the electric motor is connected to the wrist.
L, /e A robot in which the wrist drive device d4 is configured by a planar flow electric handle. 3 % r 1 Rating 1 Range The robot according to item 2 is characterized in that it is provided with wrist displacement detection means, and the control circuit is configured to control the drive of the electric motor according to the output of the detection means. A robot that does. 41PJ In the robot according to claim 1,
A robot characterized in that the above conformance mechanism is constructed by two sets of parallel spring strings each consisting of two facing parallel plates/S springs that are displaced in the X direction and the Y direction that are directly opposite to each other. . 5. In the robot according to claim 1rl, paragraph 1, two parallel springs each consisting of two pairs of parallel plates/four springs displaced in the X direction and the Y direction that intersect with each other. A cross-shaped plate to allow for displacement of the inclination angle of the thread and the arm, which acts on the arm, is fitted with a seven-shaped spring that forms the above compliance mechanism.
A robot with a distinctive character. 6 In the Law/Sotho stated in claim 3,
A robot characterized in that said wrist displacement detecting means is constructed using a strain cable. 7. In the robot described in claim 3 JJ,
A robot in which the control circuit described above is configured so that the position of negative feedback and the feedback key are negative. 8. The robot according to claim 3, wherein the control circuit is configured to make the compliance variable by switching the sign of the position feedback key between positive and negative. 9. In the robot described in paragraph 8,
A robot characterized in that the control circuit is configured to switch the signal of the Vj feedback key via an analog switch in response to a signal from a central fltlJ control device. 10 In the robot according to claim 8, 1ldl, the integral amount of the fD% signal from the number digit detection means is a positive feedback, the differential term is a negative feedback, and the surface flow key of the differential term is a positive feedback. A robot characterized by having an upper DC system @1 circuit.