JPH09160617A - Multiaxial simultaneous control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lighten the load on a control part as much as possible. SOLUTION: A servocontroller 100 is an (n+1)-axis simultaneous control type and controls servo driving systems for (n) axes individually. Measurement controllers 130a and 130b relay a detection signal from a sensor which performs previously determined detecting operation under the movement control of one of the servo driving systems for the (n) axes. A control part 200 performs predetermined processing according to data regarding control from a servocontroller 100 and the detection signal. The output of the remaining one axis of the servocontroller 100 is used for pulse output, which is synchronized with the rotating speed of the servomotor for a reference axis selected out of the servo driving systems for the (n) axes and also outputted as a measurement sampling signal to the control part 200 through a frequency dividing circuit 111. The control part 200 inputs the data regarding the control and the detection signal only when the measurement sampling signal arrives and performs the predetermined processing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-axis simultaneous control system for independently controlling a multi-axis servo drive system, and more particularly to a sensor for detecting position, distance, etc. in addition to the multi-axis servo drive system. The present invention relates to improvement of a multi-axis simultaneous control system which also has a function of processing a detection signal from a sensor while controlling a position and measuring a position, a distance, and the like. This type of multi-axis simultaneous control system, for example, measures the shape of a three-dimensional molded product for measuring the wall thickness, contour, outer diameter, etc. of a molded product such as a propeller for a ship, a propeller for an aircraft, or a turbine blade. Suitable for equipment.

[0002]

2. Description of the Related Art As a shape measuring device for a three-dimensional molded product,
The stylus type measuring device is the most popular. This measuring device usually has measuring needles applied to a plurality of points on the molded product, and measures the wall thickness of the molded product by detecting the position of the stylus of the measuring needle.

In this type of measuring device, when performing a precise measurement, a large number of points are set in order to perform measurement at each designated point, and the measuring needle is moved to a position several mm above each point and then the measurement needle is gently moved. It is necessary to lower the measuring needle and perform the stylus. Incidentally, the time required for 1-point measurement requires 1 second or more, and the moving speed of the measuring needle for the stylus is several (mm / sec). Therefore, the measurement is required as the shape of the molded product increases. The time will increase.

Further, in the case of a propeller, an error in the position of the stylus of the measuring needle becomes large at a portion having a large propeller pitch (a portion having a large curvature), which causes a problem when performing highly precise measurement. In addition, in order to measure the contour of the molded product, a contact needle different from the above measuring needle is required.

The present inventor has proposed a shape measuring device for a three-dimensional molded product using a laser sensor as a device for solving the above problems. As will be described later in detail, this shape measuring device is a device that measures the shape of the molded product using a laser sensor that measures the distance by irradiating the molded product having a three-dimensional curved surface with a laser. The laser sensors are arranged so as to face each other so that their laser irradiation axes are on the same straight line, and the molded product is moved so as to periodically cross the laser irradiation axis between the pair of laser sensors, and a position where the laser sensors cross each other. Is sequentially changed so as to obtain measured values regarding the thickness, contour, and outer diameter of the molded product from the outputs of the pair of laser sensors. Then, in order to obtain the above-mentioned measured value from the output of the laser sensor, a control unit by a computer is provided. Further, a triaxial servo drive system is provided to move the molded product and the laser sensor in a predetermined direction.

[0006]

By the way, in order to perform accurate shape measurement, it is desirable to have as many measurement sampling points as possible, but in that case, the measurement data becomes enormous and the load on the control unit for data processing is increased. Grows larger. Further, since the three-axis servo drive system is provided, it is necessary to simultaneously perform the position recognition and control of the drive target in these servo drive systems, which means that the load on the control unit is further increased. means.

In view of the above circumstances, an object of the present invention is to provide a multi-axis simultaneous control system capable of reducing the load on a control unit for managing the entire system and processing measurement data as much as possible. It is in.

[0008]

A multi-axis simultaneous control system according to the present invention includes a multi-axis simultaneous control type servo controller for individually controlling an n-axis servo drive system which performs independent proportional control. Data relating to control from a measurement controller that relays a detection signal from the sensor while controlling the operation of a sensor that is movement-controlled by one of the n-axis servo drive systems and that performs a predetermined detection operation, and control from the servo controller And a control unit that receives a detection signal from the sensor from the measurement controller and performs predetermined processing based on the control data and the detection signal, and serves as the servo controller (n + 1) A simultaneous axis control type is used, the output of the remaining 1 axis is used for pulse output, and the pulse output is used for the n-axis servo. While synchronizing with the rotation speed of the servo motor of the axis to be the reference selected from the dynamic system, it outputs as a measurement sampling signal to the control section through the frequency dividing means, and the control section receives the measurement sampling signal. Only in this case, the predetermined processing is performed by taking in the data relating to the control and the detection signal.

The control unit is provided with input means for instructing to change the setting of the frequency division ratio of the frequency dividing means, and the control portion changes the setting of the frequency dividing means by changing the setting from the input means. It is preferable to change the setting of the circumference ratio.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Before explaining specific examples of the present invention,
The shape measuring apparatus for a three-dimensional molded article, which is most suitable for applying the present invention and is proposed by the present inventor, will be described in detail with reference to FIGS. Here, the propeller 10 for a ship will be described as a measurement target. This apparatus uses a well-known laser sensor that irradiates a laser beam onto an object to be measured and receives the reflected light to measure the coordinates of the irradiation point or the distance to the irradiation point. Then, the pair of laser sensors 20
It is characterized in that a and 20b are vertically opposed to each other so that their laser irradiation axes are on the same straight line. The propeller 10 is attached to a rotating shaft 30 provided in a position parallel to the laser irradiation axis and apart from the laser irradiation axis so as to be rotatable. The extending direction of the rotary shaft 30 will be W
Called the axis. The rotary shaft 30 is driven by a servo drive system by a servo motor 32 via a speed reducer 31. The rotary shaft 30, the speed reducer 31, and the servo motor 32 may be collectively referred to as a first rotary drive system.

This first rotary drive system is constructed on an X-axis table 40 which is slidable in the left and right horizontal directions in FIG. 1 (hereinafter referred to as the X-axis direction) and is movable in the X-axis direction. . The X-axis table 40 is driven by a servo drive system including a ball screw mechanism housed in a box 41 and a servo motor (not shown) for driving the ball screw mechanism. The X-axis table 40, the ball screw mechanism, and the servomotor may be collectively referred to as a second drive system.

The pair of laser sensors 20a and 20b are also lasers with a constant interval maintained by a servo drive system including a ball screw mechanism housed in the box 21 and a servo motor (not shown) for driving the ball screw mechanism. It is movable in the irradiation axis direction (hereinafter referred to as the Z axis direction). These ball screw mechanism and servo motor may be collectively referred to as a third drive system.

In measuring the shape, the W axis is set at a position where the blades of the propeller 10 periodically cross the laser irradiation axis by the rotation of the first rotary drive system. And the second
The drive system is configured so that the locus of laser irradiation on the blades of the propeller 10 becomes a partial concentric circle by moving the X-axis table 40 in the X-axis direction by a constant distance at constant time intervals.

The first rotary drive system and the second and third drive systems are driven by a controller (not shown). The control unit also receives electric signals from the laser sensors 20a and 20b obtained by photoelectrically converting the laser light reflected by the blades of the propeller 10, performs sampling in synchronization with these two electric signals, and outputs a sampling value. Then, the coordinates of the surface of the blade are calculated from the above, and the thickness of the blade is calculated from the difference between them. Speaking of an example of such a calculation method, the laser sensor 20
The distance L between a and 20b is constant, and the laser sensor 20
Laser sensor 20b, distance La from a to the upper surface of the blade
Since the coordinates of the upper surface and the lower surface with respect to the Z axis can be known by calculating the distance Lb from the blade to the lower surface of the blade from the sampling value, the thickness of the sampled measurement point can be calculated by calculating the difference between them. It can be calculated.
Of course, the wall thickness T can be calculated by T = L- (La + Lb).

FIG. 5 shows an example of wall thickness measurement points determined by the rotation by the first rotary drive system and the movement and sampling operation in the X-axis direction by the second drive system as described above. The interval between the measurement points is set to a value of several mm to several tens of mm. In the case of the rotation direction of the propeller 10 shown by the arrow in FIG. 5, the point where the reflected light from the laser sensors 20a and 20b appears and the point where the reflected light disappears are detected as the outline of the blade indicated by the one-dot chain line in the figure. . Further, the outer diameter of the blade is calculated from the detected contour.

Next, the function of the third drive system will be described. The laser sensors 20a and 20b usually have a limited distance measurement range. That is, it is possible to measure the distance from the laser sensor to an object within a predetermined range, and the predetermined range is usually several tens cm. On the other hand, when the propeller for a ship has a diameter of several meters, the difference between the measurement points in the vertical direction becomes several tens cm or more, and the laser sensor 20
If the positions of a and 20b are fixed within the above predetermined range, the laser sensors 20a and 20b may collide with the rotating propeller 10.

Therefore, the outer shape of the propeller 10, that is, an approximate curved surface shape is created in advance by a program and stored in the memory in the control unit. The control unit controls the third drive system based on this program, and the propeller 1
In order to prevent the laser sensors 20a, 20b from colliding with the propeller 10 even if 0 is rotated,
Adjust the position of 20b in the Z-axis direction. Of course, the displacement amounts of the laser sensors 20a and 20b in this case are considered in the calculation of the wall thickness. Here, in the case of the propeller 10, since the upper and lower surfaces of the blade change with the same curvature, that is, have the same curved surface, the movement control of the laser sensors 20a and 20b in the Z-axis direction is performed by the laser sensors 20a and 20b. It is designed to work together with the interval kept constant.

However, in the case of a molded product having curved surfaces whose upper and lower surfaces do not change with the same curvature, the laser sensor 20
One laser sensor may collide with the molded product only by moving it in the Z-axis direction while keeping the distance between a and 20b constant. In consideration of such a case, the laser sensors 20a and 20b may be individually controlled to move. Even in this case, the laser sensors 20a, 20
Since it is possible to know the individual movement amounts of b, it is possible to calculate the wall thickness by performing the calculation in consideration of these movement amounts.

As is clear from the above description, this shape measuring apparatus has a three-axis drive system by proportional control of W axis, X axis, and Z axis, and has a shape measuring function by laser sensors 20a and 20b. It is necessary to process the detection signals from the laser sensors 20a and 20b while individually controlling the triaxial drive system.

FIG. 1 is a block diagram of a control system for realizing the above-described individual control of the three-axis drive system and the function of processing the detection signals from the laser sensors 20a and 20b. In the present invention, three axes of the commercially available four-axis servo controller 100 are used for individual control of the three-axis drive system, and the remaining one
It is characterized in that the axis control system is used for pulse output. That is, the 4-axis servo controller 100 connects the W-axis servo motor 32 to the servo board 103 and the driver 10 via the servo board 101 and the driver 102.
4 controls the X-axis servo motor 105, and controls the Z-axis servo motor 108 via the servo board 106 and the driver 107. The 4-axis servo controller 100 also generates a pulse signal and outputs the pulse signal through the pulse board 110. This pulse signal is frequency-divided by the frequency dividing circuit 111, and is sent as a measurement sampling signal via the interface 120 to the control unit 200.
To supply. The 4-axis servo controller 100 also has
The operation panel 112 is connected.

The four-axis servo controller 100 further includes
Regarding the X-axis, limit switches HLSX, + LSX, -LSX for detecting the reference position of the X-axis table 40 and setting the limit movement amount in the + direction and-direction from the reference position are connected. Similarly, limit switches HLSZ, + LSZ, and -LSZ are also connected to the Z axis. On the other hand, with respect to the W axis, a limit switch HLSW for detecting the rotation reference position is connected. Note that FIG.
The shape measuring device shown in (1) is housed in the measuring room to ensure the safety for the operator. The 4-axis servo controller 100 is also connected to a limit switch LS for detecting the closing of the door entering and leaving the measurement chamber, and a door clamp solenoid SOL for holding the door in a clamped state.

The control unit 200 uses, for example, a clock frequency of 1
00 (MHz), capacity 16 (MB) memory, capacity 42
A hard disk driver of 0 (MB) or more and two 3.5-inch floppy disk drivers are incorporated.

Measurement controllers 130a and 130b are connected to the laser sensors 20a and 20b, respectively. The control unit 200 uses the measurement controller 130.
The control signals for instructing the laser sensors 20a and 20b to turn on and off are output through a and 130b, and the detection signals from the laser sensors 20a and 20b are received as measurement data.

A keyboard 201 and a mouse 202 for inputting various set values to three drive systems are connected to the control unit 200 via an interface 120, and the calculation result, that is, the thickness of the blade of the propeller 10 is obtained. , A display 203 for displaying the contour, outer diameter, etc. as an image,
A printer 204 that prints out numerical values, an XY plotter 205 that plots measurement points and wall thicknesses thereof as shown in FIG. 5, are connected via an interface 120. Input of the above-mentioned program is performed through, for example, a floppy disk driver.

As described above, one feature of the present control system is that one of the four-axis simultaneous control type four-axis servo controller 100 outputs a pulse, and the pulse output is a controlled object of each of the three axes. It is used as a dedicated signal for confirming the position of (the part moved by the servo drive system). Therefore, the output pulse signal is synchronized (proportional) with the servomotor rotation speed of the reference axis selected from the three axes pulse-driven by proportional control. Here, the reference axis is the W axis. A plurality of teaching points are set at regular intervals within the movement range of the controlled object on each axis. The teaching points may be at least two points, that is, a measurement start point and a measurement end point. Then, by setting the distance between the teaching points through which the controlled object moves on each axis to an integral multiple of the distance that the controlled object moves in one pulse, the number of drive pulses for each axis is set. It is possible to know the position between the teaching points of the controlled object for each axis simply by integrating Further, since the moving distance per pulse of the controlled object on the reference axis is known, the moving distance of the controlled object on each axis can be known from the speed ratio of each axis.

On the other hand, in the frequency dividing circuit 111, the pulse outputs are integrated by a counter, and the frequency is divided by outputting a measurement sampling signal for each preset number of pulses. Therefore, the measurement sampling signal is output every time the controlled object on the reference axis moves by a certain distance. In addition, the integrated value of the counter in the frequency dividing circuit 111, when the operation for changing the frequency dividing ratio is performed by the keyboard 201, the control unit 200 sends the frequency dividing control signal indicating the changed setting value to the frequency dividing circuit 111. It is changed by outputting, and the sampling timing of the measurement sampling signal can be freely changed.

While the shape measuring operation is being performed, the 4-axis servo controller 100 keeps the 3-axis servo motor 32,
While controlling 105 and 108 simultaneously, the measurement controllers 130a and 130b are laser sensors 20a and 20b.
The coordinate (or distance) is always measured by. However, the 4-axis servo controller 100 only inputs the teaching point position where the controlled object of each axis passes, the rotation speed of the servo motor between the teaching points, and the measurement sampling signal to the control unit 200. When the measurement sampling signal arrives, the control unit 200 determines each from the teaching point of each axis that has passed first from that point and the number of drive pulses accumulated after that (the number of pulse signals generated by the 4-axis servo controller 100). While calculating and recognizing the position of the controlled object on the axis,
The measurement data is received from the measurement controllers 130a and 130b, and the position of the controlled object on each axis and the measurement data are combined to calculate the coordinates of the measurement point (or the distance to the measurement point). As described above, since only the minimum necessary data is input to the control unit 200, the load on the control unit 200 can be significantly reduced.

The embodiment of the present invention has been described so far by applying it to a propeller shape measuring apparatus having a triaxial drive system.
INDUSTRIAL APPLICABILITY The present invention can be applied not only to a shape measuring device for a molded product having a three-dimensional curved surface such as a propeller or a turbine blade, but also to position management of each axis in a multi-axis simultaneous control type machine tool having two or more axes.

[0029]

In the multi-axis simultaneous control type control system, the method of measuring the position of the controlled object on each axis using a linear scale or an encoder is the most general method. When position measurement is required, position measurement means for the number of axes is required. On the other hand, according to the method of the present invention, in the case of proportionally controlling a plurality of axes, it suffices to generate the pulse in synchronization with the reference axis, so that only one position measuring output mechanism is required. Then, the control unit does not take in all the data regarding the control from each axis and the measurement data from the measurement controller, but takes in the data only when the measurement sampling signal is input and performs the predetermined calculation. The burden can be greatly reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control system of the present invention.

FIG. 2 is a front view showing a configuration of a main part of a shape measuring apparatus to which the present invention is applied.

FIG. 3 is a plan view of a main part of the shape measuring device shown in FIG.

FIG. 4 is a side view of a main part of the shape measuring apparatus shown in FIG.

5 is a diagram showing an example of a distribution of measurement points set with respect to a propeller which is an object to be measured by the shape measuring apparatus of FIG.

[Explanation of symbols]

 10 Propellers 20a, 20b Laser Sensor 30 Rotating Axis 31 Reducer 32 Drive Motor 40 X Axis Table

Claims (2)

[Claims] 1. A multi-axis simultaneous control type servo controller for individually controlling an n-axis servo drive system that performs independent proportional control, and movement control by one of the n-axis servo drive systems. Controls the operation of a sensor that performs a predetermined detection operation, receives a data regarding control from the measurement controller that relays a detection signal from the sensor, and the servo controller, and detects from the sensor from the measurement controller. It is provided with a control unit that receives a signal and performs predetermined processing based on the control data and the detection signal, and uses the (n + 1) axis simultaneous control type servo controller, and outputs the remaining one axis. Is for pulse output, and the pulse output is for the servo motor of the axis to be the reference selected from the n-axis servo drive system. The data is output as a measurement sampling signal to the control unit through a frequency dividing unit while being synchronized with the rotation speed of the data, and the control unit takes in the data regarding the control and the detection signal only when the measurement sampling signal arrives. The multi-axis simultaneous control system, wherein the predetermined processing is performed according to the above. 2. The multi-axis simultaneous control system according to claim 1, further comprising an input unit for instructing the control unit to change a setting of a frequency division ratio of the frequency dividing unit, the control unit including the input unit. The multi-axis simultaneous control system is characterized in that the setting of the frequency division ratio in the frequency dividing means is changed by changing the setting from the.