JPH09308297A - Positioning device of plane pulse motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly shift to the next work so as to enhance availability factor by equipping this positioning device with two acceleration sensors in each axial direction mounted in a moving member, and a signal generator which transmits to a host controller the signal that the positioning is completed. SOLUTION: This is a biaxial positioning device which supplies a plane pulse motor consisting of a moving member 1 a and stator 2 with a current and positions the moving member 1 within a plane. Acceleration sensors 31 and 32 fixed to the moving member 1 detect the acceleration in X axis and Y axis, respectively. When this oscillatory acceleration is detected, a computing element operates the amplitude of the oscillation of the moving member 1, and a comparator compares the signal of the computing element with a tolerable amplitude set value. A signal generator transmits a host controller the signal that the positioning is completed, on receiving the signal from comparator. Hereby, the host controller can shift quickly to the next work, and the availability factor of a plane pulse motor can be improved.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to an automatic drafting machine and an IC.
The present invention relates to a positioning device for a flat pulse motor used in the assembling device and the like.

[0002]

2. Description of the Related Art In a pulse motor, when a pulsed current is passed through a stator, the rotor can be rotated stepwise in response to a command step, so that positioning control can be performed in an open loop. Further, it is widely known that precise rotation position control can be performed without step out by detecting the rotation position of the rotor and performing feedback control. These are also applicable to linear pulse motors and plane pulse motors. The open-loop control is widely used because it has a simple structure, but it has the drawback that if the step-out is caused by a disturbance, it will not be possible to perform the correct position control, and it will take time and effort to restore it.
If the position is detected and the feedback control is performed, such a problem disappears, but it is necessary to provide two displacement sensors, and one example thereof is disclosed in Japanese Patent Laid-Open Publication No. 5-38123. According to this method, since the space occupied by the two displacement sensors becomes large, other magnetic quantities are detected by using a magnetic sensor or a minute displacement sensor as in Japanese Patent Laid-Open No. 5-153768 and Japanese Patent Laid-Open No. 5-268792, and the calculated displacement is calculated. The method of converting into is also developed.

[0003]

However, each of the conventional methods has the following problems. Open loop control has the major drawback of stepping out depending on the disturbance, and because damping is not effective in positioning at each step and gentle damping vibration occurs, it is not possible to determine at what point the positioning is completed. It was For this reason, since it has been determined that the positioning has been completed over an unnecessarily long time and the process is moved to the next work, there is a drawback that the operating rate of the entire apparatus cannot be increased. The method disclosed in Japanese Patent Laid-Open No. 5-38123 for position detection has two long displacement sensors provided in the orthogonal direction, so that the space occupied by the sensors becomes large, the structure is complicated, and high processing accuracy is required. There is a problem that the number of man-hours increases and mechanical resonance easily occurs. In addition, Japanese Patent Laid-Open Nos. 5-153764 and 5-268792
In the method disclosed in (1), the displacement is converted from the detection signal, and the data collected in advance with the arithmetic unit is required. For this reason, there is a drawback that not only the number of steps is required, but also it is difficult to obtain a highly accurate displacement signal. The present invention has been made in view of these problems, and in a planar pulse motor positioning device for positioning by open loop control, it is possible to detect the completion of positioning and quickly move to the next work, It is intended to improve the rate.

[0004]

In order to solve this problem, in a two-axis positioning device that supplies a current to a plane pulse motor composed of a mover and a stator to control the positioning of the mover in a plane, Two acceleration sensors provided in each axial direction, a calculator that receives the signals of the two acceleration sensors and calculates the amplitude of the vibration of the mover, and a comparator that compares the signal of the calculator with the allowable amplitude set value. And a signal generator that receives a signal from the comparator and sends a signal to the upper controller that the positioning has been completed.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. 1 is a plan view of a planar pulse motor to which the present invention is applied, and FIG. 2 is a block diagram showing a signal flow of a positioning device of the present invention. In FIG. 1, reference numeral 1 denotes a moving element that can move in the X-axis direction and the Y-axis direction via a fixed air gap with the stator 2, and is supported by a support mechanism (not shown). Reference numerals 31 and 32 denote acceleration sensors fixed to the mover 1, and detect accelerations on the X axis and the Y axis, respectively.
A large number of salient poles are provided in a matrix on the surface of the stator 2. The mover 1 includes a pair of armatures in which an exciting coil is wound around a yoke having teeth, and faces the stator 2 via an air gap. The exciting coil of the mover is connected to the drive unit 9. When the drive unit 9 supplies a current, the mover 1 moves in a plane according to the current. As described above, the exciting coil of the plane pulse motor is wound around the moving element 1 unlike the rotary pulse motor. 2, 5 is the signal a _x of the acceleration sensors 31 and 32, signal l _x, calculator for calculating a l _y corresponding to the vibration amplitude undergoing a _y, 6 signals l _x of the arithmetic unit 5, l _y The comparator 7 receives the signal from the comparator 6 and compares it with a preset allowable amplitude setting value. The signal generator 7 sends a signal to the host controller 8 to receive the signal. The computing unit 5, the comparator 6, and the signal generator 7 form the positioning device 4. When the host controller 8 gives a command to the driving device 9 of the plane pulse motor,
Electric current is supplied to the moving element 1 and the moving element 1 moves in the plane.

[0006] Here, the calculation contents of the calculator 5 will be described. Now, assuming that the acceleration of the moving element 1 is a (m / s ² ) and the lead angle is φ (deg), the following equation relating to the pulse motor is generally established. M · a = (K _t · I) × Sin φ ± F (x) (1) where M is the sum of the own weight of the moving element 1 and the load weight (kg),
( _Kt · I) is a value (N) determined by the thrust constant of the motor and the stator current, and F (x) is the frictional force (N) of the mover. Here, further, the pitch of the plane pulse motor is set to t _p (m)
In other words, the vibration amplitude l of the moving element 1 is obtained as follows. l = (φ / 360) × t _p = (t _p / 360) × Sin ⁻¹ ((M · a ± F (x)) / (K _t · l)) (2) This formula is represented by X in FIG. When the axial direction and the Y-axis direction are made to correspond to each other, the following equation is obtained. l _x = (t _p / 360) × Sin ⁻¹ (M · a _x ± F (x)) / (K _t · l)) l _y = (t _p / 360) × Sin ⁻¹ (M · a _y ± F (x)) / (K _t · l)) (3) The accelerations a _x and a _y of the moving element 1 are measured by the acceleration sensors 31 and 3, respectively.
It corresponds to two signals a _x and a _y . The computing unit 6 is (3)
The acceleration signal a _x ,
The signal a _x , l corresponding to the vibration amplitude is calculated by receiving a _y.
Output _y .

In the above configuration, the host controller 8
Gives a movement / stop command, the driving device 9 of the plane pulse motor supplies a current to move the mover 1 to a predetermined position and stop it. At this time, the moving element 1 is held with a gentle damping vibration by the holding force of the magnetic attraction between the stator 2 and the salient poles of the moving element 1. When this vibration acceleration is detected by the two acceleration sensors 31 and 32, the signals a _x and a _y are obtained, and the signal l _x and l _y corresponding to the vibration amplitude is obtained by the calculator 5 that performs the calculation of equation (3). Is converted to. This signal l
_x, because l _y is a signal that gradually damped vibration gradually amplitude gradually decreases, each comparator 7 and is smaller than the allowable amplitude setting value l _m previously set the output signal to Hi. Then, the signal generator 7 receiving this signal generates a signal adapted to the input interface of the host controller 8, and notifies that the positioning of the mover 1 has been completed. After this, the host controller receiving this signal can shift to the next work.

[0008]

As described above, according to the present invention, when the vibration amplitude obtained from the acceleration of the mover becomes equal to or less than the allowable value, the signal for informing that the positioning is completed is generated.
The host controller can promptly and surely move to the next work, the operating rate of the open loop type flat pulse motor can be improved, and the system reliability is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a flat pulse motor to which a positioning device of the present invention is applied.

FIG. 2 is a block diagram of a positioning device of the present invention.

[Explanation of symbols]

 1 Moving Element 2 Stator 31 X-Axis Acceleration Sensor 32 Y-Axis Acceleration Sensor 4 Positioning Device 5 Computing Unit 6 Comparator 7 Signal Generator 8 Upper Controller 9 Drive Device

Claims (1)

[Claims] A planar pulse motor positioning device that supplies a pulsed electric current to a planar pulse motor composed of a mover and a stator to move the mover in a plane to perform positioning control. An acceleration sensor, an arithmetic unit that receives the signals of the two acceleration sensors and calculates the amplitude of the vibration of the mover, a comparator that compares the signal of the arithmetic unit with an allowable amplitude setting value, and a signal of the comparator. A positioning device for a planar pulse motor, comprising: a signal generator that receives the signal and sends a signal to the host controller that the positioning has been completed.