JP2577950B2 - Non-contact digitizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digitizer for digitizing a model shape and creating an NC program.

2. Description of the Related Art In an optical sensor that irradiates an object with the luminous flux of an infrared LED and condenses the reflected light on a position detecting element by a light receiving lens and outputs a signal, the detecting element is set at an optimal angle for receiving light. Must be installed at an angle. For this reason, a shadow area is formed, and there is always a dead zone with one sensor, and the inclination angle to be measured is limited. Conventionally, to solve this problem, the sensor head is controlled by two axes to change the tilt angle of the sensor, and the rotation is performed to make the turning plane parallel to the traveling direction, and all the model shapes are measured. I was able to do it.

Problems to be Solved by the Invention The two-axis control method of the sensor head described in the related art has problems that the control is complicated, it is difficult to increase the scanning speed, and the data processing is complicated. Was.

The present invention has been made in view of these problems of the prior art, and has as its object the purpose of all model shapes up to ± 90 ° including a vertical wall that does not require two-axis control of the sensor head. Is to provide a digitizer that can be measured.

Means for Solving the Problems In order to achieve the above object, a non-contact digitizer according to the present invention mounts a model on a table and moves in a three-axis direction of X, Y, and Z relatively to the model. A digitizer having a tracer head that is freely driven and has a mechanism capable of accurately detecting the position thereof, wherein the digitizer receives or receives light symmetrically on a plane including a Z axis perpendicular to a moving direction in an X axis direction or a Y axis direction. Two non-contact type distance sensors (A, B) that incorporate a light emitting, light projecting means and light receiving displacement detecting means provided at an angle suitable for A) a tracer head for detecting the position of one point on the model measurement surface, and a deviation value DE between two consecutive measurements of the tracer head with respect to the measurement surface.
When F is zero or positive, the measurement surface selects the sensor on the rear side with respect to the traveling direction as a flat surface or an upward slope, and when the deviation value DEF of the measurement value is negative, the measurement surface is a downward slope with respect to the traveling direction. Means for selecting the sensor on the front side, and sending the tracer head at a commanded speed in the moving direction so that the output signal of the selected sensor becomes a constant value, while deriving the measurement surface from a deviation value of previous and current data. Means for calculating a tilt angle, calculating a Z-axis speed using the tilt angle, and controlling a height position of the sensor from the measurement surface in the Z-axis direction, and the constantly changing tracer head obtained by this control X
A digitizing control device that calculates model surface coordinate values based on scanning data based on output signals corresponding to coordinate values of the axis or the Y axis and the Z axis and the distance information to the measurement surface of the selected sensor and creates NC shape data. It enables tracing of model shapes up to ± 90 ° including vertical walls.

In addition, a digitizer having a tracer head having a mechanism for mounting a model on a table and being driven to be movable in three X, Y, and Z directions relative to the table and capable of accurately detecting the position thereof. Is provided symmetrically with respect to a plane including the Z-axis perpendicular to the movement direction in the X-axis or Y-axis direction, and is provided at an angle suitable for light reception or reception at an angle suitable for light reception or reception. Two sets of non-contact type distance sensors (A1) that incorporate a pair of light-emitting, light-projecting means and light-receiving displacement detecting means that simultaneously detect the positions of two points separated by a fixed distance and measure the distance to the model surface , A2, and B1, B2), a tracer head that simultaneously detects the positions of two points on the measurement surface using any one set, and the deviation of the measurement value when the tracer head simultaneously measures two points on the measurement surface. Value DE
When F is zero or positive, the measurement surface is a plane or an up slope, and the sensor on the rear side in the traveling direction is selected.When the deviation value DEF of the measurement value is negative, the measurement surface proceeds as a down slope. Means for selecting the set of sensors on the front side in the direction, and the position of the two points while sending the tracer head at a command speed in the moving direction so that the output signal of the selected set of sensors becomes a constant value. Means for calculating the inclination angle of the measurement surface with respect to the movement direction from the three-dimensional coordinate values of the three-dimensional coordinate value, calculating a velocity vector component in the movement direction from the inclination angle, and controlling the height position of the sensor from the measurement surface; The scanning data based on the obtained constantly changing coordinate values of the X-axis or Y-axis and the Z-axis of the tracer head and the output signal corresponding to the distance information to the model measurement surface of the selected set of sensors are used. And a digitizer control device for calculating NC surface data by calculating Dell surface coordinate values, and enabling tracing of a model shape up to ± 90 ° including a vertical wall.

The tracer head is attached to the tip of the quill for the tracer head in the Z-axis direction, and is tilted at an optimal angle for light reception provided in parallel with the Y-axis when the movement axis of the Y-axis in the spindle head movement direction is provided. Of the two sensors A and B having the non-contact type distance measuring function, the sensor on the rear side in the traveling direction is selected when the surface shape of the model measures a flat surface and an upward slope (+ DEF), and the downward slope is selected. When measuring (−DEF), the front sensor is selected.

Compare the Z-axis coordinate value obtained by the measurement at a certain time with the Z-axis coordinate value obtained by the previous measurement (calculate the difference)
Then, let this be DEF. If the absolute value of this DEF is within a certain range, it is regarded as a plane. If the absolute value of this DEF exceeds this certain range, if it changes to the + side, it is judged as an up slope, and if it changes to the-side, it is judged as a down slope. .

Then, while sending the tracer head at the command speed in the moving direction so that the sensor output on the selected side becomes a constant value, the inclination angle of the measurement surface is calculated from the deviation value between the previous and current data, and the inclination angle is used. The movement of the quill for the tracer head in the Z-axis direction is controlled by calculating the Z-axis speed based on the coordinate value of each axis of the tracer head and an output signal corresponding to distance information to the measurement surface of the selected sensor. Each coordinate value of the model surface is calculated from the scanning data to create shape data by NC.

Further, two sensors A1 and A2 simultaneously detect the positions of two points on the Y-axis separated from each other by a predetermined distance.
2 or B1 and B2, and in the case of the right line (FIG. 4), the sensors B1 and B2 for detecting the position on the rear side in the traveling direction are:
In the case of the left row (FIG. 5), the sensors A1 and A2 for detecting the rear position in the traveling direction are selected, and the selected sensors are inclined (+ DE).
F), that is, for the sensor output obtained by the measurement at a certain time, the Z-axis coordinate value of the bright point on the front side and the Z-axis coordinate value of the bright point on the rear side in the moving direction are compared (difference). Is calculated), and this is defined as DEF. If the absolute value of this DEF is within a certain range, it is regarded as a plane. If the absolute value of this DEF exceeds this certain range, if it changes to the + side, it is judged as an up slope, and if it changes to the-side, it is judged as a down slope. .

Two sensors A1, A2 or B1, B2 simultaneously detect the position of two points, calculate the inclination angle of the model surface, and also calculate the velocity vector component of the moving axis. .

Embodiment An embodiment will be described with reference to the drawings. 1 and 2, in a well-known digitizer, a model table 3 for mounting a model 2 is movably mounted on a slide guide surface cut in a bed 1 in the X-axis direction. Controlled. A square column 4 is erected on both sides of the bed 1, and a spindle head 6 is movably mounted on a slide guide surface in the Y-axis direction of a cross beam 5 mounted on the column 4.
Is used to control the Y axis. A quill 7 for tracer head is provided on the spindle head 6 so as to be movable in the Z-axis direction, and is controlled by the NC. The tracer head 9 attached to the tip of the tracer head quill 7 measures the range that cannot be measured with a single sensor in order to solve the limit of measurement on the slope of the sensor and the blind spot that is destined to have an optical measuring device. The angle β1 optimal for light reception or reception with respect to a plane including the Z axis perpendicular to the movement direction Y axis
Two sensors A and B, which are tilted symmetrically back and forth with respect to the traveling direction and detect the position of the same point on the model, are mounted side by side in the Y-axis direction.

As the sensors A and B, for example, an H3065 type optical distance sensor manufactured by Hamamatsu Photonics Co., Ltd. can be used, which irradiates a target object with a light beam of an infrared LED through a light projecting lens and receives the reflected light. The light is condensed on a position detecting element by a lens, and is calculated in a controller based on an output position signal of the detecting element corresponding to distance information to an object to output an analog voltage corresponding to the distance. And the output voltage of the sensor A or B is always a constant value (for example, zero volt)
A digitizer control device 11 that controls the Z-axis by the control means of the digitizer control device and creates NC shape data from the scanning data of the moving axis and the quill for the tracer head is installed near the bed. I have.

Next, the scanning procedure will be described with reference to the flowchart of FIG.

In step S1, it is determined whether the traveling direction of the spindle head 6 in the Y-axis direction is rightward. If yes, in step S2, it is determined whether the displacement output DEF of the sensor is zero or greater than zero. If yes, in step S3 As shown in FIG. 4, the measurement points on the model surface are flat or uphill (+
DEF), and the sensor B is selected by the selecting means of the digitizing control device. If NO, the sensor A is selected by the selection means in step S4 because it is a downward slope (-DEF).

In step S1, if the traveling direction of the spindle head 6 is leftward, the determination is NO, and in step S5 it is determined again whether DEF is zero or greater than zero.
In FIG. 5, the measurement point on the upper surface of the model is a flat surface or an upward slope (+ DEF) as shown in FIG. 5, and the sensor A is selected by the selection means. If NO, the sensor B is selected by the selecting means in step S7 because the slope is downhill (-DEF).

Next, in step S8, there is an output signal from the selected sensor, and it is determined whether this output data can be read. If no, the sensor A or B is switched in step S9 and the sensor A or B is switched in step S10. Is selected again, and in step S11, it is determined whether the output data from the sensor can be read.
In step 2, it is determined whether the circuit is within the data read setting circuit input in advance. If yes, the process returns to step S10, and if no, the process returns to the first measurement point and restarts the measurement in step S13. Then, in step S14, it is determined whether or not the value is within the set value of the number of return times.
Return to S10, and if no, stop the alarm.

If yes in steps S8 and S11, step S15
In step S16, model surface coordinate values are calculated.
In, the inclination angle is calculated from the deviation value DEF between the previous and current data, and in step S17, the Z-axis speed is calculated. Then, in step S18, tolerance processing is performed by performing tolerance processing. In step S19, NC shape data is created, and in step S20, the data is stored. Then, the process returns to step S1, and one-dimensional scanning is performed by repeating the above. Next, as shown in FIG. 6, two sensors A1 and A2 are incorporated in the sensor A, and B1 and B2 are incorporated in the sensor B so that the positions a and b separated by a certain distance in the Y-axis direction can be simultaneously detected. Are incorporated. The sensors A1 and B1 measure the position a, and the sensors A2 and B2 measure the position b. Detection of DEF and calculation of the velocity vector component are performed by a combination of A1, A2 and B1, B2.

Next, a scanning procedure using the sensors A1, A2, B1, and B2 will be described with reference to FIG.

The description of the same parts as those in the flowchart of FIG. 3 is omitted or simplified in order to avoid duplication.

In steps S1 to S7, sensor A or B is selected, and in step S8, it is determined whether sensor output data can be read. If no, steps S10 to S14 are repeated until step S11 becomes yes, and the number of repetitions is The alarm stops when the set number of times is exceeded.

If yes in steps S8 and S11, step S1
In 5, it is determined whether the selected sensor is A1, and if yes, in step S16, the sensor A2 is selected,
If no, in step S17, the sensor B2 is selected. Thus, when the traveling direction is rightward or leftward as shown in FIGS. 8 and 9, the sensor A performs position detection at A1 or the sensor B at B1. A2 or a combination of B1 and B2 are selected.

In step S18, it is determined again whether the data can be read. If no, the alarm is stopped. If yes, the model surface coordinate values are calculated in step S19. That is, the three-dimensional coordinates of the point sequence along the moving direction of the model surface are obtained by the above-described method.

Measurement point P1 on the rear side (X1, Y1, Z1) Measurement point P2 on the front side (X2, Y2, Z2) In step S20, the inclination angle is calculated from the deviation value DEF of the data of the sensors A2, A1 or B2, B1 measured simultaneously. Is calculated. That is, assuming that the inclination angle is θ, DEF = Z2-Z1 when the moving direction is the direction of the Y-axis θ = tan ^-1 {DEF / (Y2-Y1)} In step S21, the scanning speed given using this angle is used. A speed vector component is calculated from (command speed) to determine the Y-axis and Z-axis axis speeds.

In steps S22 to S24, tolerance processing is performed.
NC data is created and stored, and the process returns to step S1 to perform three-dimensional scanning by repeating the above.

The sensor is not limited to an optical non-contact sensor, and a non-contact sensor using an ultrasonic wave or the like can be used.Effect The present invention is configured as described in detail above. The following effects are obtained.

In the non-contact type digitizer according to the first aspect, the tracer head is provided with two optical sensors which are tilted back and forth in the moving direction at an optimum angle for light reception, and one of the two sensors is moved in the traveling direction and the traveling direction. Since the measurement is automatically selected according to the measurement surface shape, the tracer head is controlled by two axes to eliminate the blind spot (shadow area), which is an optical defect, without tilting. All the shapes up to can be measured.

According to the non-contact type digitizer of the second aspect,
Can be used to detect the position of two points apart from each other, so that the speed vector component can be calculated in addition to the effect of claim 1, and even if the sensor has an unknown shape, it can be detected at a smooth speed. Can perform dimensional scanning.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a digitizer, a control device and a model of the present invention, FIG. 2 is an explanatory diagram showing an attached state of two sensors, FIG. 3 is a flowchart for explaining the operation of claim 1,
4 and 5 are explanatory diagrams of the selection conditions of the sensor in FIG. 2, FIG. 6 is an explanatory diagram showing a mounting state of the sensor for detecting the positions of two distant points according to claim 2, and FIG. FIG. 8 and FIG. 9 are flow charts for explaining the operation of the item 2, and FIG. A, A1, A2, B, B1, B2… Sensor 9… Tracer head 11… Digitizer control device

Claims (2)

(57) [Claims] 1. A tracer head having a mechanism for mounting a model on a table, being driven movably in three X, Y, and Z directions relative to the table and capable of accurately detecting the position thereof. A light emitting and projecting means provided symmetrically on a plane including the Z axis perpendicular to the moving direction in the X-axis or Y-axis direction and inclined at an angle suitable for receiving or receiving light in the moving direction. And a non-contact type distance sensor (A, B) that has a built-in light receiving displacement detecting means and measures the distance to the same point on the model measurement surface, and detects the position of one point on the model measurement surface And a deviation value DE of two consecutive measurement values with respect to the measurement surface by the tracer head.
When F is zero or positive, the measurement surface selects the sensor on the rear side with respect to the traveling direction as a flat surface or an upward slope, and when the deviation value DEF of the measurement value is negative, the measurement surface is a downward slope with respect to the traveling direction. Means for selecting the sensor on the front side, and sending the tracer head at a commanded speed in the moving direction so that the output signal of the selected sensor becomes a constant value, while deriving the measurement surface from a deviation value of previous and current data. Means for calculating the Z-axis speed using the tilt angle, calculating the Z-axis speed using the tilt angle, and controlling the height position of the sensor from the measurement surface in the Z-axis direction, and the constantly changing tracer head obtained by this control A digitizer that calculates NC model data by calculating model surface coordinate values from scanning data based on the X-axis or Y-axis, Z-axis, coordinate values, and output signals corresponding to the distance information to the measurement surface of the selected sensor. Noncontact digitizer comprises a control device, characterized in that to enable tracing of the model shape at ± 90 DEG, including vertical walls. 2. A tracer head having a mechanism for mounting a model on a table, being driven to move relative to the table in three X, Y, and Z directions, and capable of accurately detecting the position of the model. A digitizer having an angle suitable for light reception or reception symmetrically with respect to a plane including a Z axis perpendicular to the X axis or Y axis direction of movement, and moving on a model measurement plane. A non-contact type distance sensor that incorporates a pair of light-emitting, light-emitting means and light-receiving displacement detecting means for simultaneously detecting the positions of two points separated by a certain distance on the axis and measures the distance to the model surface. Pair (A1, A2 and B1, B2)
A tracer head that simultaneously detects the positions of two points on the measurement surface by any one of the sets, and a deviation value DEF of a measurement value obtained when the tracer head simultaneously measures two points on the measurement surface is zero or positive. When the measurement surface is a flat surface or ascending slope, the sensor on the rear side with respect to the traveling direction is selected, and when the deviation value DEF of the measured value is negative, the measurement surface is located on the forward side with respect to the traveling direction as a downward slope. Means for selecting the set of sensors, and moving the trace saddle from the three-dimensional coordinate values of the positions of the two points while sending the trace saddle at a command speed in the moving direction so that the output signal of the selected set of sensors becomes a constant value. Means for calculating the inclination angle of the measurement surface with respect to the direction, calculating the velocity vector component in the moving axis direction from the inclination angle, and controlling the height position of the sensor from the measurement surface, and changing every moment obtained by this control. X-axis of the serial tracer head or Y
A digitizer control device that calculates model surface coordinate values based on scanning data based on coordinate values of the axes and the Z axis and output signals corresponding to distance information to the model measurement surface of the selected set of sensors to create NC shape data; A non-contact digitizer characterized in that it is possible to trace a model shape up to ± 90 mm including a vertical wall.