JPH0135826Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a master-slave manipulator device that can adjust the weight balance when handling heavy objects.

One of the power manipulator devices is a master-slave manipulator (hereinafter simply referred to as an MS manipulator). The MS manipulator has a structure in which when a worker operates a master arm, a slave arm operates in response to the movement of the master arm.

Conventionally, MS manipulators have balanced the weight of the slave arm itself to improve operability, and when there is no load, the slave arm can be moved even if the master arm is operated with almost zero operating force.

However, when handling heavy objects, there is no way to balance the weight, so the force of the load is directly transmitted to the master arm, making it difficult to operate the master arm and causing fatigue.

Therefore, the purpose of the present invention is to provide a master-slave manipulator device that can eliminate such drawbacks and reduce the operating force of the master arm by adjusting the force balance of the slave arm even when handling heavy objects. do.

The structure of the present invention to achieve such an object includes a master arm rotatably provided at one end of the frame, and a slave arm rotatable at the other end in a one-to-one relationship with the rotation of the master arm. In the master-slave manipulator device, a weight measurement sensor is provided to measure the weight handled by the slave arm, and the sensor is fixed to the master arm and extends beyond the supporting portion of the master arm to the frame on an extension line of the master arm. A balancer that generates a moment around the support part that balances the moment due to the weight of the master arm is fixed to the extending support member, and a balancer that is parallel to the slave arm is attached to a guide plate fixed to the master arm in the vicinity of the support part. A screw shaft is pivotally supported on the screw shaft, and the screwing position is changed to generate a moment around the support portion that balances the weight measured by the weight measurement sensor and the moment due to the slave arm's own weight. It is characterized by the weights being screwed together.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

First, the principle of the present invention will be explained based on FIG. A bearing 2 is attached to the inner wall 1 of a support such as a cell.
A frame 3 is rotatably supported substantially horizontally through the frame 3. A slave arm 7 is provided at one end of the frame 3, and a master arm 6 is provided at the other end. Note that although the slave arm 7 and master arm 6 are normally set substantially parallel to each other, they may be set with a slight phase shift as shown in FIG. And the fulcrum of the weight of slave arm 7 itself
The moment with respect to R ₁ (the moment with respect to the fulcrum R ₁ when no weight is applied to the slave arm 7), or the weight of the slave arm 7 itself and the moment with respect to the fulcrum R ₁ of the weight when the slave arm 7 is loaded with weight. In order to prevent the moment from being directly transmitted to the master arm 6, a balancing moment configuring means is provided for configuring a balancing moment that balances the moment generated with respect to the fulcrum _R1 . In this embodiment, the following structure is adopted as the balancing moment forming means. Since the master arm 6 moves in a one-to-one correspondence with the slave arm 7, the ball screw 1 is fixed integrally with the master arm 6 and is always parallel to the slave arm 7 so that the ball screw 12 rotates.
2 is fixed to a fulcrum R ₂ , and a weight 13 is screwed onto the ball screw 12 .

Now, the weight 1 is such that when W ₁ = 0 (no weight is applied to the slave arm 7), F = 0 (the master arm 6 is suspended without applying any force).
[The position of the center of gravity of the slave arm 7 can be expressed as kL (k<1, which can be regarded as a substantially constant) with respect to the variable L].

W ₂ ×kL _sio θ=W ₃ × _sio θ ∴=W ₂ kL/W _3. Next, with the weight 13 fixed at the position of = W ₂ kL/W ₃ = ₀ , a weight of W ₁ is applied to the slave arm 7. If F is the force that must be applied to the master arm 6 to maintain balance, then W ₁ L _sio θ + W ₂ kL _sio θ = W _{3 0sio} θ + FL _{F 0} = W ₂ KL/W ₃ Then, F=W ₁ L _sio θ/L _{F L} Since F is constant, W ₁ increases, so the longer L becomes, the greater F must be increased (Here, θ is not considered because it constantly changes). Increasing F means increasing the operator's operating force, which means that the operation is difficult. In order to make F small even when W ₁ and L become large, the position of the weight 13 is made variable, and the moment suspended with respect to the fulcrum R ₁ is
3 should be applied to the fulcrum _R2 . If we create a suspension equation with variables as W ₁ L _sio θ+W ₂ kL _sio θ =W ₃ l _sio θ+FL _F ∴=W ₁ L _sio θ+W ₂ kL _sio θ−FL _F /W _3sio θ Here, the operator Given the condition F = 0 that allows them to hang together with almost no force applied, = L (W ₁ + kW ₂ ) / W ₃ ...(1) Since L and W ₁ are variables in this equation, the slave arm 7's By constantly detecting the total length and the weight handled by the slave arm 7 and moving the weight 13 so that the value satisfies the above equation (1), F
=0, that is, master-slave 6 with operating force close to zero
can be operated.

Examples are shown below. FIG. 2 is an overall perspective view, and FIG. 3 is an explanatory diagram showing a cross section of part A in FIG.
FIG. 4 is a sectional view taken along the line BB in FIG. 3.

As shown in Fig. 2, the inner wall 1 of the cell etc. that is the support body
A frame 3 is rotatably supported substantially horizontally via a bearing 2, a slave arm 7 is connected to one end of the frame 3 by hanging down, and a master arm 6 is connected to the other end via housings 4 and 5. are connected by hanging down. The rotation of the master arm 6 at the fulcrum _R2 is directly transmitted as the rotation of the slave arm 6 at the fulcrum _R1 in a one-to-one correspondence. Master hand 8 is attached to master arm 6 and slave arm 7.
and a slave hand 9 are provided so as to be extendable and retractable. And, as explained earlier in explaining the principle, a balancing moment forming means is provided. That is, two guide plates 14 are provided on an extension of the upper part of the master arm 6 and rotate together with the master arm 6. Note that, unlike the case in Figure 1, the master arm 6 and slave arm 7
2, the master arm 6, slave arm 7, and guide plate 14 all operate in a parallel state. Two guide plates 1
Between 4 and 4 is a linear bearing 15 (see Fig. 5,
A weight 13 is provided so as to be able to move up and down via a rotatable roller 15', and the distance between the two guide plates 14 is maintained constant by support plates 16 provided above and below. . A ball screw 12 is rotatably provided between the upper and lower support plates 16 via a bearing 17, and the ball screw 12 is screwed into a nut 18 fitted approximately at the center of the weight 13. A worm wheel 19 is integrally fixed to the upper part of the ball screw 12, and two mutually parallel housings 20, 2 are integrated with the upper support plate 16 and protrude downward.
The rotating shaft 2 of the motor 22 attached to the
The worm 24 integrated with 3 is the worm wheel 19
meshes with Therefore, when the motor 22 is rotated, the weight 13 can be moved up and down. on the other hand,
A potentiometer (or an encoder may be used) 25 is provided below the ball screw 12 to detect the rotation speed of the ball screw 12 via a gear train.
A servo mechanism is constructed that determines the position of the weight 13 (that is, the value of in FIG. 1) by detecting the signal from the potentiometer 25. In addition to the above (1)
Formula L (length of slave arm 7 in Figure 2) W ₁
(The weight handled by the slave hand 9 in FIG. 2) is provided with a full length measurement sensor and a weight measurement sensor. Here, the explanation of the weight measurement sensor will be omitted, and the full length measurement sensor will be explained. The slave arm 7 has a structure shown in FIG. The slave arm 7 is located between the fixed pipe 26 , a middle pipe 27 housed inside the fixed pipe 26 , and a support pipe 28 fixed integrally with the middle pipe 27 inside the middle pipe 27 . It consists of a lower stage pipe 19 that is housed. Since the shaft 30 is driven by an external driving force and the screw shaft 31 is further rotated, the screw shaft 31
A nut 32 that is screwed into the nut 32 moves up and down in the figure, and a middle pipe 27 that engages with this nut 32 is guided by a bearing unit 33 and moves up and down. Further, when the screw shaft 35 is rotated by the motor 34 provided at the lower end of the lower pipe 29, a nut 36 which is screwed into the core screw shaft 35 is fixed to the tip of the support pipe 28, so the lower pipe 29 is rotated by a bearing. It moves up and down guided by the unit 37. Because of the structure described above, the slave arm 7 can have its entire length changed to various lengths. In order to know the total length of the slave arm 7, the screw shaft 31,
Since it is sufficient to know the number of rotations of the screw shaft 35, encoders 38 and 39 are attached to the end of the screw shaft 31 and the motor 34 that rotates integrally with the screw shaft 35. In addition, in this embodiment, in order to balance the weight of the master arm 6 itself, a balancer 11 is provided on the upper extension line of the master arm 6 via a support member 10.

The operation of such a master-slave manipulator device will be explained. Assuming that the total length of slave arm 7 is a certain value L and a load of weight W ₁ is lifted,
These values are detected by encoders 38 and 39 and a weight measurement sensor (not shown), and the values of equation (1) are calculated based on these detection signals (k, W ₂ , W ₃
is determined in advance). Then, the weight 13 is moved to the calculated position by the action of the potentiometer 25 and motor 22. Such an action is performed manually or automatically each time the total length L of the slave arm 7 or the weight _W1 handled by the slave arm 7 changes. As a result, the operator's operating force is reduced to approximately zero, improving operability and reducing fatigue.

In this embodiment, a case has been described in which the total length of the slave arm changes, but if it does not change, it is sufficient to set L=constant in equation (1) and provide only a weight measurement sensor.

As described above with the drawings,
According to the present invention, the operating force of the master arm can be reduced to approximately zero by automatically or manually rotating the motor and moving the weight based on the total length of the slave arm and the weight handled by the slave arm. Not only is it easier to operate the master arm when handling heavy objects, but it also reduces fatigue and improves operability.

Furthermore, according to the present invention, the balancer that compensates for the dead weight of the master arm and the weight mechanism that compensates for the dead weight of the slave arm and the weight handled by the slave arm are arranged together at the upper end of the master arm. does not interfere with the operation of the operator.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of a master-slave manipulator according to the present invention, FIGS. 2 to 6 are an implementation of the master-slave manipulator according to the present invention, FIG. 2 is a perspective view showing the whole, and FIG. The figure is an explanatory diagram showing the section A of Fig. 2, and Fig. 4 is the section B of Fig. 3.
5 is a perspective view of the bearing unit, and FIG. 6 is a sectional view of the slave arm. In the drawing, 3 is the frame, 6 is the master arm,
7 is a slave arm, 12 is a ball screw, 13 is a weight, and 38 and 39 are encoders.

Claims (1)

[Scope of utility model registration request] In a master-slave manipulator device, a master-slave manipulator device includes a master arm rotatably provided at one end of a frame, and a slave arm rotatable in a one-to-one relationship with the rotation of the master arm at the other end,
A weight measurement sensor is provided to measure the weight handled by the slave arm, and a support member fixed to the master arm and extending on an extension line of the master arm beyond the support portion of the master arm for the frame is provided. fixing a balancer that generates a moment around the support part that balances the moment due to its own weight, and pivotally supporting a screw shaft parallel to the slave arm on a guide plate fixed to the master arm in proximity to the support part; A weight is screwed onto the screw shaft, and the screwing position of the weight is changed in order to generate a moment around the support part that balances the weight measured by the weight measurement sensor and the moment due to the slave arm's own weight. A master-slave manipulator device characterized by: