JP2003097938A - Control device, control means, shape measuring device and robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device allowing a probe-equipped actuator to move at a high speed and locating it to a specified position in a short time even if it has a wider operating range. SOLUTION: The control device is provided with a position control system based on a position control compensator 20 as well as a speed control system based on a speed control compensator 18 to enable high-speed motion of the actuator 9 equipped with the probe 1 by switching such control modes as a speed control mode, a position control mode and a follow-up control mode in a given sequence. Additionally the device can not only locate the actuator to the specified position in a short time despite its wider operating range, but also allow it to be in a certain loaded contact condition without damaging the probe 1 or a subject 10 due to collision with a surface of the subject 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device, a control method, a shape measuring device and a robot when using a contact probe or a non-contact probe.

[0002]

2. Description of the Related Art Generally, in a shape measuring apparatus for measuring a three-dimensional shape of a surface to be inspected, a contact type probe such as a stylus type probe or a non-contact type probe using an optical displacement gauge is used as an actuator. If the probe is mounted and touches the surface to be inspected in the case of a contact type probe, in the case of a non-contact type probe, for example, in the focused state with respect to the surface to be inspected, the measurement is performed by scanning along the surface shape I have to.

Regardless of which type of probe is used, it is necessary to control the position of the actuator equipped with the probe so that the actuator is brought closer to a desired position from the initial position.

In this respect, for example, according to Japanese Patent No. 2977521 and Japanese Patent Laid-Open No. 2-254634, a structure provided with a position control system and a focus servo system in the case of a non-contact type probe using an optical displacement gauge. Then, a method of setting the initial position of the objective lens in the vicinity of the outside of the focus pull-in range and then moving the objective lens to a desired position (position at which an in-focus point is achieved) only by controlling the position of the actuator is described.

[0005]

However, when the movement range of the actuator (dynamic lens for measurement) is wide, only position control by the position control system is necessary to move the actuator to a desired position. It takes time. As a result, there is a problem that the measurement time becomes long.

Further, when the focus position is searched from the vicinity of the outside, if the laser beam of the optical displacement meter is scattered due to dust or scratches on the surface to be inspected and the focus signal cannot be detected well, the actuator ( There is also a risk of colliding the objective lens) with the surface to be inspected.

In the case of a contact type probe such as a stylus type probe, if the probe is strongly pressed against the surface to be inspected, the probe may be destroyed. The example of the publication relates to a non-contact type probe that uses an optical displacement meter, and no mention is made of measures against this. In particular, there are cases where a contact probe that is supported by a soft spring and that easily vibrates and is poorly damped is used, or a false signal is likely to be input due to the influence of dust adhering to the surface to be inspected or the probe tip. obtain.

Therefore, an object of the present invention is to provide a control device and a control method that enable high-speed movement of an actuator equipped with a probe and can position the actuator at a predetermined position in a short time even if the operating range is wide. And

Further, the present invention is directed to a control device and a control method capable of preventing an abnormal load from being generated and destroying the probe or the surface to be inspected, or the control of the contact type probe becoming in a non-contact state and becoming unstable. The purpose is to provide.

Further, according to the present invention, when the contact type probe is used as the probe, the actuator equipped with the contact type probe can be moved at high speed and can be positioned at a predetermined position in a short time even if the operating range is wide. An object of the present invention is to provide a control device and a control method capable of bringing the contact type probe and the test object into a contact state with a predetermined load without colliding with the test surface and destroying the contact probe or the test object.

Further, the present invention provides a control device which, when a contact type probe is used as the probe, is provided with a mechanism for determining that the probe is in contact with the surface to be inspected and which can stably bring the contact state with a predetermined load. The purpose is to do.

Further, according to the present invention, when a non-contact type probe equipped with an optical displacement gauge is used, an actuator equipped with the non-contact type probe can be moved at a high speed and is stable in a short time even if the operating range is wide. It is possible to provide a control device and a control method capable of performing a focused focus retraction operation and not damaging an optical displacement meter or an object to be inspected or a probe to which the optical displacement meter is applied by colliding with a surface to be inspected. To aim.

Further, according to the present invention, when a non-contact type probe equipped with an optical displacement gauge is used, the method and the configuration of the optical displacement gauge are different, and the calculation method of the focus signal from the light receiving element is different. There may be some zero-cross points in the focus signal, and it is possible to pull the focus to the wrong zero-cross point during the focus pull-in operation.Therefore, by adding the total amount of light received by the light-receiving element to the focus pull-in determination, An object of the present invention is to provide a control device that can stably perform a focus pull-in operation.

Further, according to the present invention, when a non-contact type probe equipped with an optical displacement meter is used, the focus inclination (change of the focus signal with respect to the distance) at the zero-cross point where the focus pull-in is performed is the opposite inclination. In this case, the control system may oscillate. Therefore, an object of the present invention is to provide a control device capable of performing reliable focus pull-in by adding the inclination of the focus signal to the determination.

Further, the present invention provides a control device which minimizes the positional deviation when the focus is retracted and stably retracts the focus when a non-contact type probe equipped with an optical displacement meter is used. With the goal.

[0016]

According to a first aspect of the present invention, there is provided a control device including an actuator having a probe facing a surface to be inspected, a position detecting section for detecting a displacement of the actuator and generating a position signal. A position control compensator for performing position control based on the output of the probe or the position signal, a speed control compensator for performing speed control based on a speed signal calculated from the position signal, the position control compensator or the speed A drive circuit that drives the actuator based on the operation amount from the control compensator.

Therefore, since not only the position control system by the position control compensator but also the speed control system by the speed control compensator is mounted, it becomes possible to move the actuator equipped with the probe at a high speed, and the operating range is short even if it is wide. It can be positioned in place in time.

According to a second aspect of the present invention, in the control device according to the first aspect, the speed control for driving the actuator by the speed control using the speed control compensator so that the probe approaches the vicinity of the test surface. The mode executing means and the mode are switched at the time when the probe approaches a predetermined position with respect to the surface to be inspected, and the actuator is controlled by position control using the position control compensator based on the position signal by the position detector. Position control mode executing means for driving the, and when the output of the probe reaches the vicinity of a predetermined value, the mode is switched, and the output of the probe is controlled by the position control using the position control compensator based on the output of the probe. Follow-up control mode executing means for driving the actuator so that the actuator has a predetermined value.

Therefore, since the speed control mode, the position control mode, and the follow-up control mode are switched in a predetermined order, the actuator equipped with the probe can be moved at a high speed, and even if the operation range is wide, the predetermined range can be achieved in a short time. In addition to being able to perform positioning at a position, the probe and the test object can be brought into contact with each other with a predetermined load without colliding with the surface of the test object and destroying the probe and the test object.

According to a third aspect of the present invention, in the control device according to the second aspect, the position control mode executing means is provided with a first search operation and a second search operation, and the actuator feed of the first search operation is performed. A feed changing unit that changes the actuator feed speed so that the actuator feed speed of the second search operation becomes slower than the speed is provided.

Therefore, by changing the feed speed of the actuator when searching for a position that can be switched to the follow-up control mode using the probe output, it is possible to speed up the state determination of the probe and improve the accuracy of detecting the predetermined switching position. Both can be achieved, and switching to the tracking control mode by the probe output can be performed at high speed and with high accuracy.

According to a fourth aspect of the present invention, in the control device according to the second or third aspect, the determining means for determining whether or not the output of the probe exceeds a predetermined range when the actuator is driven by the follow-up control mode executing means. And when the predetermined range is exceeded, the control is switched to the control by the position control mode executing means.

Therefore, when the output of the probe exceeds the predetermined range, the tracking control mode based on the probe output is changed to
By switching to the position control mode based on the position signal of the position detection unit, it is possible to prevent the probe and the test object from being destroyed and the control of the probe from becoming unstable.

According to a fifth aspect of the present invention, in the control device according to the fourth aspect, the predetermined range is variably set according to operating conditions.

Therefore, by variably setting the predetermined range for switching to the position control mode based on the signal from the position detection section according to the operating conditions of the device, a safe operation according to the operating conditions of the device is ensured. can do.

According to a sixth aspect of the present invention, in the control device according to the first aspect, the probe is a spring-supported contact type probe, and the contact type probe is brought into contact by speed control using the speed control compensator. Immediately before the speed control mode executing means for driving the actuator to a position near the surface to be inspected, and the mode is switched when the contact probe approaches the position in the vicinity of the surface to be inspected, and the position detected by the position detector Position control mode executing means for driving the actuator in a direction in which the contact type probe comes into contact with the surface to be inspected by position control using the position control compensator based on a signal, and the output of the contact type probe is near a predetermined value. The mode is switched at the time when the position is reached, and the position is controlled by the position control compensator based on the output of the contact probe. The output of the contact probe is provided with a follow-up control mode executing means for driving the actuator to a predetermined value.

Therefore, since the control mode is switched in a predetermined order of the speed control mode, the position control mode and the follow-up control mode, the actuator equipped with the contact type probe can be moved at high speed and the operating range is wide. The positioning can be performed at a predetermined position in a short time, and the contact type probe and the test object can be brought into a contact state with a predetermined load without colliding with the test surface and destroying the contact probe or the test object.

According to a seventh aspect of the present invention, in the control device according to the sixth aspect, there is provided output change monitoring means for monitoring a change in output of the contact type probe when the position control mode executing means drives the actuator. A change in the output of the contact type probe is detected as an inclination in a predetermined direction by the output change monitoring means, and when the output of the contact type probe reaches the vicinity of a predetermined value, the control is switched to the control by the follow-up control mode execution means. did.

Therefore, since the contact with the surface to be inspected is determined by detecting the inclination of the output of the contact type probe, the contact state with a predetermined load can be stably established.

According to an eighth aspect of the present invention, in the control device according to the first aspect, the probe has a built-in optical displacement meter, and a focus signal is output as a probe output based on an output of a light receiving element of the optical displacement meter. And a speed control mode executing means for driving the actuator from an initial position to a predetermined position in the vicinity farther from the surface to be inspected than the focus pull-in position by speed control using the speed control compensator. , The mode is switched when the contact probe approaches the predetermined position,
Position control mode executing means for driving the actuator in a direction approaching the surface to be inspected by position control using the position control compensator based on the position signal by the position detection unit, and a position where the actuator can focus pull-in. When it reaches, the mode is switched, and the actuator is driven so that the focus signal becomes a predetermined value by the position control using the position control compensator based on the focus signal by the optical displacement meter, and the focus pull-in operation is performed. And a follow-up control mode execution means for performing the operation.

Therefore, by sequentially switching the speed control mode, the position control mode, and the follow-up control mode as the control mode, the focus pull-in operation time can be increased even when the operation range of the actuator equipped with the optical displacement gauge is wide. It can be shortened.

According to a ninth aspect of the present invention, in the control device according to the first aspect, the probe has a built-in optical displacement meter, and a focus signal is output as a probe output based on an output of a light receiving element of the optical displacement meter. A non-contact type probe that performs speed control using the speed control compensator, and speed control mode executing means for driving the actuator from an initial position to a predetermined position closer to the surface to be inspected than the focus pull-in position, and When the contact probe approaches the predetermined position, the mode is switched, and the actuator is driven in the direction away from the surface to be inspected by the position control using the position control compensator based on the position signal by the position detection unit. The position control mode executing means for causing the actuator and the actuator to reach the position where the focus can be pulled in Tracking by switching the mode and driving the actuator so that the focus signal becomes a predetermined value by the position control using the position control compensator based on the focus signal from the optical displacement meter. A control mode executing means.

Therefore, although the same effect as that of the invention of claim 8 can be obtained, in particular, by making the direction of the focus retraction operation away from the object to be inspected, the focus retraction can be performed in a short time and the object to be inspected. It is possible to prevent the optical displacement meter or the object to be inspected or the probe to which the optical displacement meter is applied from being damaged by colliding with the surface.

The invention according to claim 10 is the invention according to claim 8 or 9.
In the control device described above, a feed distance of the actuator toward a position where focus can be pulled in when the actuator is driven by the position control mode executing means is set to a predetermined distance.

Therefore, by limiting the feed distance (focus search distance) of the actuator during the focus pull-in operation to a predetermined distance, it is possible to prevent a collision with the object to be inspected, and in addition, it is impossible to pull the focus. It can be detected early and can enhance safety.

According to an eleventh aspect of the present invention, in the control device according to the eighth, ninth or tenth aspect, the light receiving element is a light receiving element having a divided structure for detecting a focus signal, and the position control mode execution is performed. In the search operation by the means, when the focus signal has a value capable of pulling the focus when the actuator is driven, and the total amount of light received by the light receiving element is equal to or greater than a predetermined value, the follow-up control mode executing means causes the focus pulling operation.

Therefore, some zero-cross points may occur in the focus signal due to differences in the method and configuration of the optical displacement meter, differences in the method of calculating the focus signal from the light receiving element output, etc. There is a possibility of pulling the focus to the wrong zero cross point,
By adding the total amount of light received by the light receiving element to the focus pull-in determination, stable focus pull-in operation can be performed.

The invention according to claim 12 is the invention as claimed in claims 8, 9,
10. The control device according to 10 or 11, further comprising output change monitoring means for monitoring a change in the focus signal when the actuator is driven in the search operation by the position control mode execution means, wherein the focus signal is a value capable of pulling the focus. When the change in the focus signal is detected as a tilt in a predetermined direction by the output change monitoring means, the follow-up control mode execution means causes the focus pull-in operation.

Therefore, if the tilt of the focus at the zero-cross point where focus pull-in is performed (change of the focus signal with respect to the distance) is the opposite tilt, the control system may oscillate, but the tilt of the focus signal The focus pull-in operation can be surely performed by adding the direction of (4) to the determination.

According to a thirteenth aspect of the present invention, in the control device according to the twelfth aspect, the focus pull-in operation is performed when the state in which the change in the focus signal is the inclination in the predetermined direction is continuously detected for a predetermined time or longer. Let

Therefore, since the inclination of the focus signal can be observed in a time series by adding the temporal determination, it is possible to suppress the malfunction due to the noise component included in the focus signal.

The invention according to claim 14 is the invention as defined in claims 8, 9 and
In the control device of 10, 11, 12 or 13, output change monitoring means for monitoring a change in a focus signal when the position control mode executing means drives the actuator, and a time point when the focus signal reaches a value capable of pulling the focus. Then, the tracking control mode execution means changes the target value of the position control by the focus signal to the value of the focus signal at that time, switches to the position control by the focus signal to perform the focus pull-in, and then the position control by the original focus signal. Target value changing means for switching to the target value of.

Therefore, by changing the focus target position, the positional deviation at the moment of focus pull-in can be minimized, and the focus can be stably pulled in.

According to a fifteenth aspect of the present invention, in the control method, an actuator having a probe facing the surface to be inspected, a position detecting section for detecting a displacement of the actuator and generating a position signal, an output of the probe or the Position control compensator for position control based on a position signal, speed control compensator for speed control based on a speed signal calculated from the position signal, and operation from the position control compensator or the speed control compensator Using a drive circuit for driving the actuator based on the amount, a speed control mode execution step of driving the actuator so that the probe approaches the vicinity of the surface to be tested by speed control using the speed control compensator, The mode is switched when the probe approaches a predetermined position with respect to the surface to be inspected, and the position detected by the position detector is changed. Position control mode executing step for driving the actuator by the position control using the position control compensator based on the signal, and switching the mode when the output of the probe reaches the vicinity of a predetermined value. Tracking control mode execution step of driving the actuator so that the output of the probe becomes a predetermined value by the position control using the position control compensator based on the output of.

Therefore, since the speed control mode, the position control mode, and the follow-up control mode are switched in a predetermined order, the actuator equipped with the probe can be moved at a high speed, and a predetermined range can be achieved in a short time even if the operation range is wide. In addition to being able to perform positioning at a position, the probe and the test object can be brought into contact with each other with a predetermined load without colliding with the surface of the test object and destroying the probe and the test object.

According to a sixteenth aspect of the present invention, there is provided a control method comprising: an actuator equipped with a contact probe supported by a spring and facing a surface to be detected; and a position detector for detecting a displacement of the actuator and generating a position signal. A position control compensator that performs position control based on the output of the probe or the position signal, a speed control compensator that performs speed control based on a speed signal calculated from the position signal, the position control compensator, or the Using a drive circuit that drives the actuator based on the operation amount from the speed control compensator, the speed is controlled by using the speed control compensator, and the contact type probe is brought to a position in the vicinity of the surface to be inspected immediately before the contact probe is contacted. Speed control mode execution step to drive the actuator and mode switching at the time when the contact probe approaches the position near the surface to be inspected A position control mode in which the actuator is driven in a direction in which the contact probe contacts the surface to be inspected by position control using the position control compensator based on the position signal by the position detector. When the output of the contact-type probe reaches a predetermined value, the mode is switched, and the output of the contact-type probe is controlled by the position control using the position control compensator based on the output of the contact-type probe. A follow-up control mode execution step of driving the actuator so that the value becomes a value.

Therefore, the control mode is switched in a predetermined order of the speed control mode, the position control mode, and the follow-up control mode, so that the actuator equipped with the contact type probe can be moved at high speed and the operating range is wide. The positioning can be performed at a predetermined position in a short time, and the contact type probe and the test object can be brought into a contact state with a predetermined load without colliding with the test surface and destroying the contact probe or the test object.

According to a seventeenth aspect of the present invention, in a control method, an optical displacement gauge is built in, a focus signal is output as a probe output based on an output of a light receiving element of the optical displacement gauge, and a non-contact facing a surface to be inspected. An actuator equipped with a probe, a position detector that detects the displacement of the actuator and generates a position signal, a position control compensator that performs position control based on the output of the probe or the position signal, and from the position signal Using the speed control compensator that performs speed control based on the calculated speed signal, and a drive circuit that drives the actuator based on the operation amount from the position control compensator or the speed control compensator, the speed control compensation The actuator is driven from the initial position to a predetermined position near the surface to be inspected from the focus pull-in position by speed control using a device. And the speed control mode execution step that,
The mode is switched when the contact probe approaches the predetermined position, and the actuator is moved in a direction away from the surface to be inspected by position control using the position control compensator based on the position signal by the position detector. A position control mode execution step of driving and performing a search operation, and a position using the position control compensator based on a focus signal from the optical displacement meter by switching the mode when the actuator reaches a position where focus can be pulled in. A follow-up control mode executing step of driving the actuator so that the focus signal has a predetermined value by control and performing a focus pull-in operation.

Therefore, by sequentially switching the speed control mode, the position control mode, and the follow-up control mode as the control mode, the focus pull-in operation time can be increased even when the operation range of the actuator equipped with the optical displacement gauge is wide. It can be shortened.

The control method according to the eighteenth aspect of the present invention incorporates an optical displacement meter, outputs a focus signal as a probe output based on the output of the light receiving element of the optical displacement meter, and outputs a non-contact facing the surface to be inspected. An actuator equipped with a probe, a position detector that detects the displacement of the actuator and generates a position signal, a position control compensator that performs position control based on the output of the probe or the position signal, and from the position signal Using the speed control compensator that performs speed control based on the calculated speed signal, and a drive circuit that drives the actuator based on the operation amount from the position control compensator or the speed control compensator, the speed control compensation The actuator is driven from the initial position to a predetermined position near the surface to be inspected from the focus pull-in position by speed control using a device. And the speed control mode execution step that,
The mode is switched when the contact probe approaches the predetermined position, and the actuator is moved in a direction away from the surface to be inspected by position control using the position control compensator based on the position signal by the position detector. A position control mode execution step of driving and performing a search operation, and a position using the position control compensator based on a focus signal from the optical displacement meter by switching the mode when the actuator reaches a position where focus can be pulled in. A follow-up control mode execution step of driving the actuator so that the focus signal becomes a predetermined value by control and performing a focus pull-in operation.

Therefore, the same effect as that of the seventeenth aspect of the invention can be obtained, but in particular, by setting the direction of the focus retraction operation to be a direction away from the object to be inspected, focus retraction can be performed in a short time, and the object to be inspected It is possible to prevent the optical displacement meter or the object to be inspected or the probe to which the optical displacement meter is applied from being damaged by colliding with the surface.

The shape measuring apparatus according to the nineteenth aspect of the invention is
The control device according to any one of claims 1 to 14 is mounted, and the surface shape of the test object is measured by scanning the probe along the test surface shape while controlling the output of the probe to a predetermined value. .

Therefore, by mounting the control device according to any one of claims 1 to 14 on the shape measuring device,
A shape measuring device having a wide dynamic range and capable of measuring a highly accurate shape under a low load can be provided.

A robot according to a twentieth aspect of the present invention is equipped with the control device according to any one of the first to eighth aspects, and controls the output of the probe to a predetermined value so that the probe follows the shape of the surface to be inspected. To follow.

Therefore, by mounting the control device according to any one of claims 1 to 8 on the robot, the compliance control is performed at a predetermined load under a low load that has a wide dynamic range and does not damage the surface to be inspected. Can be done.

[0056]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first embodiment of the present invention.
Or, it demonstrates based on FIG. The control device of the present embodiment is applied to a contact load control device, and the contact probe in the contact load control device detects a contact load. In this embodiment, an example in which a stylus probe capable of detecting a low load is used as the contact probe will be described.

FIG. 1 is a sectional structural view showing an example of a stylus probe 1. A true sphere 3 that comes into contact with the surface of the surface to be detected is attached to the tip of the stylus 2. The stylus 2 is the housing 4
It is supported in a non-contact state by the static pressure air bearing 6 that is supplied with air from the air supply hole 5 formed in the above, and is restrained in the lateral direction, so that it can move in the vertical direction without receiving sliding resistance. It is considered as a structure. Reference numeral 7 is a spring that supports the stylus 2 and is fixed to the housing 4. Reference numeral 8 is a displacement gauge for detecting the displacement between the stylus 2 and the housing 4. The housing 4 is a moving stage 9 (FIG.
Installed).

The spring 7 supporting the stylus 2 is a coil spring,
Any mechanism such as a leaf spring, a hinge, an air spring, or a magnetic spring may be used as long as the mechanism generates a force by displacement. Further, the lateral support mechanism of the stylus 2 is not limited to the static pressure air bearing 6, and any support mechanism having a high lateral rigidity such as a parallel leaf spring may be used. The displacement meter 8 may be of any type such as an optical type, an electrostatic capacitance type, an operating transformer type, a laser length measuring device, and the like.

The basic operation of contact load control of the stylus probe 1 will be briefly described. When the true sphere 3 at the tip of the stylus 2 is pressed against the test surface of the test object 10 (see FIG. 2), the stylus 2 is positioned at a position where the spring force balances with the reaction force from the test surface. Moving. At that time, the output of the displacement meter 8 changes. Therefore, by controlling the position of the moving stage 9 on which the housing 4 is mounted so that the output of the displacement gauge 8 is always constant, the contact load on the surface to be measured is kept constant.

Next, the structure of a vertical type contact load control device equipped with such a stylus probe 1 will be described with reference to FIG.

The movable stage 9 on which the stylus probe 1 is mounted is vertically supported by a gravity compensation spring 11. This moving stage 9 has a voice coil motor 12
A linear encoder 13 is provided as a position detection unit that constantly detects the position z of the moving stage 9 by using the drive source as a driving source.

On the other hand, a motor driver 14 is provided as a drive circuit for supplying a motor current im to drive the voice coil motor 12. A control circuit 15 is connected to the motor driver 14.

The structure of the control circuit 15 will be described. First, a speed calculator 16 that calculates a speed v based on the position z information of the moving stage 9 detected by the linear encoder 13 is provided. In addition, the speed calculator 16
Comparator 1 for comparing the speed calculated by
7 is provided, and a speed control compensator 18 that receives the speed deviation ev obtained by the comparator 17 and outputs a target current value ic that is an operation amount according to the speed deviation ev to the motor driver 14 is provided. .

Further, a comparator 19 for comparing the position z of the moving stage 9 detected by the linear encoder 13 with the target position is provided, and the position deviation ez obtained by the comparator 19 is input to the position deviation ez. A position control compensator 20 that outputs a target current value ic that is a corresponding operation amount to the motor driver 14 is provided.

Further, the displacement amount δz, which is the probe output obtained from the displacement gauge 8 of the stylus probe 1, the contact load set by the spring constant of the spring 7 supporting the stylus probe 1 and the target contact load. A comparator 21 for comparing with a corresponding target position is provided, and the position deviation ez obtained by this comparator 21 is input to the position control compensator 20. That is,
The position control compensator 20 detects the position signal z or the probe output δz.
The position control is performed on the basis of the above, and a switch 22 for switching the input system according to the mode is provided.

A switch 23 is also provided for switching control of the motor driver 14 between the speed control compensator 18 side and the position control compensator 20 side.

The control circuit 15 receives the displacement amount δz, which is the probe output obtained from the displacement gauge 8 of the stylus probe 1, as an input, and sets the target speed, the target position, and the load-equivalent target position in order to switch the control mode. Switches 21, 22
A mode switching controller 24 is provided for controlling the switching. The mode switching controller 24 is a CPU
It is constructed by a computing unit such as a DSP. In response to an operation command from the system control PC 25 or the like placed on a higher level, the mode switching controller 24 causes the speed control mode, the position control mode, and the load control based on a predetermined calculation from the current state of the contact load control device. The mode (follow-up control mode) is switched and the target value is set. The mode switching controller 24 is an arithmetic unit that is completely independent of the host PC 25 and the like, and has a shared memory, an I / O port,
It communicates via a serial port, etc., and sends and receives operation commands and status.

In the example shown in FIG. 2, the mode switching controller 24 is shown in the form of an arithmetic unit different from the speed control compensator 18, the position control compensator 20, the mode switching switches 22 and 23, and the like. The range surrounded by the alternate long and short dash line (control circuit 15) can be constructed in the same arithmetic unit.

The operation modes of the contact load control system of the present embodiment having such a configuration will be described.

<Speed control mode> Linear encoder 13
The velocity v is calculated by the velocity calculator 16 from the position z information of the moving stage 9 detected by. The calculated speed v and the target speed set by the mode switching controller 24 are input to the comparator 17 to calculate the speed deviation ev. The speed deviation ev is input to the speed control compensator 18, and the manipulated variable ic corresponding to the speed deviation is output. Here, the manipulated variable is set to the target current value ic. The target current value ic is input to the motor driver 14, and the motor current im is supplied to the voice coil motor 12 to drive the moving stage 9 in the vertical direction by speed control.

<Position Control Mode by Encoder> The position z of the moving stage 9 detected by the linear encoder 13 and the target position set by the mode switching controller 24 are input to the comparator 19 and the position deviation ez is calculated. The position deviation ez is input to the position control compensator 20 and an operation amount ic corresponding to the position deviation is output. Here, the manipulated variable is set to the target current value ic. The target current value ic is input to the motor driver 14, and the motor current im is supplied to the voice coil motor 12 to drive the moving stage 9 in the vertical direction by position control.

<Position control mode by probe signal> When the stylus probe 1 comes into contact with the surface of the object 10, the displacement amount δz which is the output from the displacement meter 8 mounted on the stylus probe 1, Information on the spring constant of the spring 7 supporting the stylus 2 and the target position equivalent to the contact load set by the mode switching controller 24 from the target contact load is obtained by the comparator 21.
And the position deviation ez is calculated. The position deviation ez is input to the position control compensator 20, and the manipulated variable ic corresponding to the position deviation ez is output. Here, the manipulated variable is set to the target current value i
Let be c. The target current value ic is input to the motor driver 14 to cause the motor current im to flow in the voice coil motor 12 and drive the moving stage 9 in the vertical direction by position control by the output of the stylus probe 1.

Operation of bringing the stylus probe 1 into contact with the surface of the object 10 and switching to position control using the output of the stylus probe 1 so that the output of the stylus probe 1 reaches a predetermined value. 3, an example of operation control using these operation modes will be described with reference to FIG.

In FIG. 3, the case where the moving stage 9 moves upward is defined as a positive direction, the case where the moving stage 9 moves downward is defined as a negative direction, and in addition, the lower end surface of the illustrated moving stage 9 is used as a position reference. explain.

In the δz search operation for switching to the position control mode based on the output signal δz of the stylus probe 1, FIG.
The mode switch 23 is switched to A to move the stylus probe 1 from the initial position in FIG. 3 to the contact load search start position in the positive direction from the position corresponding to the set load in the speed control mode. The moving direction in the speed control mode can be positive or negative depending on the initial position of the moving stage 9.

Next, the switch 22 for mode switching is set to A
Then, switch the switch 23 to B, and the linear encoder 1
The position control mode according to 3 is executed. The target position is changed in the negative direction and the moving stage 9 is moved in the direction of approaching the object 10.

At the same time as position control by the linear encoder 13, the output signal δz of the stylus probe 1 is constantly observed, and when the position can be switched to the position control mode by the output signal δz of the stylus probe 1, the mode is set. The switch 22 for switching is switched to B, and the switch 23 is kept at B to execute the position control mode by the output signal δz of the stylus probe 1. The output signal δz of the stylus probe 1 at this time is a displacement corresponding to the contact load. In the position control by the output signal δz of the stylus probe 1, the position control is always performed such that the output signal δz becomes the load-equivalent target position δzref.

Assuming that the load-equivalent target position is δzref, the initial value of the output δz is δz0, the spring constant of the spring 7 supporting the stylus 2 is kp, and the set load is fp, the load-equivalent target position δ.
zref is represented by δzref = (fp / kp) + δz0 …………………… (1).

An example of such operation mode control executed by the mode switching controller 24 will be described with reference to the flowchart shown in FIG. First, when the moving stage 9 is stopped, it is stopped at an arbitrary position by the position control mode shown in step S1. Then, it is determined at any time whether switching to the load control mode, which is the position control mode (following control mode) by the output δz of the stylus probe 1 has been designated (S2). When the switch to the load control mode is designated (Y in S2), the switch 23 is switched to shift to the speed control mode and move to a predetermined position (S3). The process of step S3 is executed as a speed control mode execution means or a speed control mode execution step.

When it is determined that the vehicle has moved to the predetermined position (contact load search start position) in this speed control mode (Y in S4), the position control mode is switched by switching the switches 22 and 23 (S5). In this position control mode, the moving stage 9 is slightly moved by changing the target position little by little in the minute feed mode, and the stylus probe 1 is brought into contact with the surface to be inspected of the object 10 (S).
6). The processing of these steps S5 and S6 is executed as position control mode execution means or position control mode execution steps.

In the processing of this position control mode, it is determined at any time whether the output δz of the displacement gauge 8 for detecting the displacement of the stylus probe 1 has reached a switchable predetermined value (S).
7). When the output δz reaches a switchable predetermined value and can be switched (Y in S7), the target position in the position control mode is set to the load-equivalent target position δzref, and the position detection means is switched by switching the switch 22. The load control mode is executed by switching to the output δz of (S
8). The processing of step S8 is executed as the follow-up control mode execution means or the follow-up control mode execution step.

Therefore, according to the present embodiment, basically, by providing not only the position control compensator for the position control mode but also the speed control compensator for the speed control mode, the stylus probe 1 It becomes possible to move the moving stage 9 (actuator) mounted with the high speed at a high speed, and the movable stage 9 can be positioned at a predetermined position in a short time even in a wide operation range and can be brought into contact with a predetermined load.

As shown in FIGS. 3 and 4, since the speed control mode, the position control mode, and the load control mode are switched in a predetermined order, the moving stage 9 (where the stylus probe 1 is mounted The actuator can be moved at a high speed and can be positioned at a predetermined position in a short time even if the operation range is wide, and the probe probe 1 or the object 10 is destroyed by colliding with the surface of the object 10. Without doing so, it is possible to bring them into contact with a predetermined load.

A second embodiment of the present invention will be described with reference to FIGS.
It will be described based on. The same parts as those shown in the first embodiment are designated by the same reference numerals and the description thereof will be omitted (the same applies to each of the following embodiments).

This embodiment is based on the operation control as shown in FIGS. 3 and 4. That is, the moving stage 9 is moved to the contact load search start position in the speed control mode. Next, the switch 22 for mode switching is switched to A and the switch 23 is switched to B to shift to the position control mode by the linear encoder 13. The target position is changed in the negative direction and the moving stage 9 is moved toward the object 10. Simultaneously with such position control by the linear encoder 13, the output signal δz of the stylus probe 1 is constantly monitored.

The output signal δz during the δz search operation is shown in FIG. When the stylus probe 1 is in a non-contact state with the surface of the object 10, the mechanical resonance frequency of the spring constant of the spring 7 supporting the stylus probe 1 and the stylus 2 is the initial value of δz. The output signal δz oscillates near the value δz0. When the stylus probe 1 comes into contact with the surface of the object to be inspected 10, the contact rigidity of the stylus probe 1 is improved, the vibration of the stylus probe 1 is converged, and the stylus probe 1 accompanying the movement of the moving stage 9 is moved. Is output as δz. In FIG. 5, it can be seen that the stylus probe 1 contacts the test object 10 in the vicinity of 10 seconds and the displacement changes in the negative direction. This displacement in the negative direction is the inclination in the predetermined direction. After the displacement in the negative direction is detected and contact is determined, the output signal δz moves to a position near the load-equivalent target position δzref, the mode switching switch 22 is switched to B, and the output of the stylus probe 1 is output. Position control is performed by the signal δz.

As a method of detecting the inclination of the output signal δz of the stylus probe 1, there are a method of comparing data for each sampling and a method of taking a difference. Here, the current data is δ (n), the data before sampling is δ (n-1)
Then, δ (n) <δ (n−1) …………………………………………………………………………………………………… (2) If the condition is satisfied, the slope of Is detected and the contact of the stylus probe 1 is detected.

However, since the actual data contains a noise component, the output signal δz of the stylus probe 1 is low-pass filtered or averaged to detect the slope using the noise-reduced data. It will be.

Therefore, in the present embodiment, in the flow chart of FIG. 6 corresponding to FIG. 4, the output signal δz of the stylus probe 1 is constantly monitored during execution of the fine feed mode (S6), and the stylus is detected. A process for determining whether or not a change in the output of the expression probe 1 is detected as an inclination in a predetermined direction as shown in Expression (2) is added (S9). This step S9
Is executed as a function of the output change monitoring means.

That is, in the position control mode (S5),
In the minute feed mode, the moving stage 9 is slightly moved by gradually changing the target position to bring the stylus probe 1 into contact with the object 10 (S6). During this mode processing, it is determined whether or not the output δz (n) of the displacement gauge 8 for detecting the displacement of the stylus probe 1 is smaller than the value δz (n-1) one sampling before (S9). ), If the conditions are satisfied (S9), it is determined whether or not the output δz of the displacement gauge 8 for detecting the displacement of the stylus probe 1 is a switchable predetermined value (S7). If switchable (S
7), the target position in the position control mode is switched to the load-equivalent target position δzref, and the switch 22 switches the position detection means to the output δz of the stylus probe 1 to shift to the load control mode.

Therefore, according to the present embodiment, there is provided means for determining that the stylus probe 1 has come into contact with the surface of the object 10 by detecting the inclination of the output of the stylus probe 1. Therefore, the contact state with a predetermined load can be stably established.

FIG. 7 and FIG. 8 show the third embodiment of the present invention.
It will be described based on.

When a probe that easily vibrates is used, the displacement of the vibration in the negative direction is erroneously detected as a predetermined inclination, or dust is attached to the tip of the probe or the surface of the object to be inspected. When the dust moves due to the addition, the inclination may be erroneously detected at the moment of contact with the dust. If the tilt is erroneously detected and the position control is switched to the output signal δz of the stylus probe 1, the output signal δz of the stylus probe 1 cannot be accurately detected, and the control system may oscillate. is there.

Therefore, in the present embodiment, in order to determine that the stylus probe 1 has contacted the surface of the object 10, the stylus probe 1 as in the second embodiment described above.
In addition to detecting the inclination of the output δz of the stylus probe 1, when the predetermined inclination of the output δz of the stylus probe 1 continues for a predetermined time or longer, it is determined that the stylus probe 1 has come into contact with the surface of the test object 10. It is something that is done. In FIG. 7, the contact of the stylus probe 1 is determined by detecting the inclination in the negative direction for 4 seconds from 10 seconds to 14 seconds. Also in this case,
Since the actual data contains a noise component, the output signal δz of the stylus probe 1 is subjected to low-pass filter processing or averaging processing, and the noise-reduced data is used to detect the slope.

Therefore, in the present embodiment, the control is performed by the flowchart shown in FIG. 8 instead of FIG. In step S9, the inclination is determined by calculating δ (n) <δ (n-1), the time tcnt during which this inclination continues is counted (S10), and if the inclination does not continue, tcnt is reset (S12). ). It is determined whether the inclination time is equal to or longer than a predetermined time (S11), and when the condition is satisfied (S1
1), a displacement gauge 8 for detecting the displacement of the stylus probe 1
It is determined whether the output δz of is a predetermined switchable value (S7). If it can be switched (Y in S7), the target position in the position control mode is switched to the load-equivalent target position δzref, and the switch 22 switches the position detection means to the output δz of the stylus probe 1 to shift to the load control mode. .

Therefore, according to the present embodiment, since the contact is determined by detecting the inclination of the output of the stylus probe 1 for a predetermined period of time, it is supported by a soft spring and vibrates. Even if a stylus probe that is easy and has poor attenuation is used, or even under the condition that an erroneous signal is likely to be input due to the influence of dust adhering to the surface of the object 10 or the probe tip, The contact with the surface can be determined, and the contact state with a predetermined load can be stably achieved.

By the way, in the present embodiment, when the output δz of the stylus probe 1 is kept at the predetermined slope for a predetermined time or longer, the stylus probe 1 is used as the object 10 to be inspected.
When it is determined that the output signal δz has come into contact with the surface, the output signal δz may have passed a position near the load-equivalent target position δzref. If the moving stage 9 is driven in the negative direction as it is, the stylus probe 1 or the object 10 may be damaged.

Therefore, in such a case, after it is determined that the probe type probe 1 has come into contact with the surface of the test object 10, the target position δzref corresponding to the load is compared with the current probe output δz, and the moving stage 9 is moved. It suffices to determine the driving direction of.

The operation will be described with reference to FIG. δz
In the search operation, the moving stage 9 is driven in the negative direction by changing the target position in the negative direction. At 10 seconds, the stylus probe 1 comes into contact, detects the inclination of the signal for 4 seconds, and determines that it is in the contact state. At this point, since the target position δzref corresponding to the load has passed,
The target position is reversed in the positive direction and the moving stage 9 is driven in the positive direction. When the output δz of the stylus probe 1 enters a range of a predetermined value near the load-equivalent target position δzref,
The mode switching switch 22 is switched to B to shift to the load control mode by the output signal δz of the stylus probe 1.

According to this, since the position which can be switched to the position control using the output of the stylus probe 1 is searched for, the position signal of the linear encoder 13 (position detector) of the moving stage 9 (actuator) is searched. It is possible to stabilize the transient response when the position control mode is switched to the load control mode using the output of the stylus probe 1.

A fourth embodiment of the present invention will be described with reference to FIGS. The basic operation of the present embodiment is similar to that shown in FIG. 9, but the inclination of the output δz of the stylus probe 1 continues at the predetermined slope for a predetermined time or longer, and the stylus probe 1 is inspected. The feed speed of the moving stage 9 until the first search operation for determining that the surface of the object 10 has been contacted,
After the contact determination, the feed speed of the moving stage 9 in the second search operation for searching the vicinity of the load equivalent target position δzref is made different, and the feed speed of the moving stage 9 for contact determination is set to the vicinity of the load equivalent target position δzref. It is faster than the search speed.

The operation will be described with reference to FIG. In the δz search operation, in the first search operation, the moving stage 9 is driven in the negative direction by changing the target position in the negative direction at the feed speed V1. The stylus probe 1 comes into contact at 10 seconds, and the inclination of the signal is detected for 2 seconds to determine that it is in a contact state. In the second search operation, since the load-equivalent target position δzref has passed at this point, the target position is fed at a feed rate V2 slower than the feed rate V1.
(The relationship between the speeds V1 and V2 is | V1 |> | V2 |), and the moving stage 9 is driven in the positive direction by reversing in the positive direction.
The output δz of the stylus probe 1 is the target position δzre corresponding to the load.
When it enters the range of a predetermined value in the vicinity of f, the mode switching switch 22 is switched to B, and position control is performed by the output signal δz of the stylus probe 1.

Therefore, in the present embodiment, the control is performed by the flowchart shown in FIG. 11 instead of FIG. The initial speed setting in the minute feed mode in step S6 is V1. The inclination of the output δz is determined (S9),
The time tcnt during which the inclination continues is counted (S10),
The feed speed in the minute feed mode is set to V2 (S13). If the slope does not continue, tcnt is reset (S12),
The feed speed in the minute feed mode is set to V1 (S14). V
2 is slower than V1. Steps S13 and S1
The processing of No. 4 is executed as a function of the feed speed changing means.
It is determined whether the tilt time is a predetermined time or more (S1
1) If the conditions are satisfied (Y in S11), it is determined whether or not the output δz of the displacement gauge 8 for detecting the displacement of the stylus probe 1 is a switchable predetermined value (S7). If it can be switched (Y in S7), the target position in the position control mode is switched to the load-equivalent target position δzref, and the switch 22 switches the position detection means to the output δz of the stylus probe 1 to shift to the load control mode. .

Therefore, according to the present embodiment, by changing the speed of the moving stage 9 (actuator) when searching for a position where the output of the stylus probe 1 can be switched to position control, the stylus is changed. It is possible to achieve both high speed determination of contact of the probe 1 and high accuracy of predetermined switching position detection, and high speed and high accuracy switching to a contact state of a predetermined load. Further, the contact determination time can be shortened by shortening the predetermined time for detecting the inclination of the output δz of the stylus probe 1, and the detection stability can be stabilized by slowing the speed for detecting the vicinity of the load-equivalent target position δzref. And the stability of switching to the position control based on the output signal δz of the stylus probe 1 can be ensured.

The fifth embodiment of the present invention will be described with reference to FIG.

As described above, the output δz of the stylus probe 1 in the operation of determining that the stylus probe 1 has come into contact with the surface of the object 10 or in the operation of searching for the vicinity of the load-equivalent target position δzref. Noise or disturbance may affect normal operation.
Therefore, since the moving stage 9 continues to move, the stylus probe 1 and the test object 10 may collide with each other and be destroyed.

Therefore, in the present embodiment, the moving range of the moving stage 9 in such an operation is limited to a predetermined distance. When the contact determination or the search in the vicinity of the load-equivalent target position δzref cannot be performed even after moving the predetermined moving distance, the moving stage 9 stops and the above operation is ended.

Such operation control will be described with reference to FIG. In the δz search operation, the moving stage 9 is driven in the negative direction by changing the target position in the negative direction. In normal operation, the contact of the stylus probe 1 is determined by the operation as in each of the above-described embodiments, and the vicinity of the load-equivalent target position δzref is searched, but noise to the output δz of the stylus probe 1 is detected. The contact state cannot be determined due to disturbance, and the moving stage 9 continues to be driven in the negative direction beyond the load-equivalent target position δzref. When the moving stage 9 moves a predetermined moving distance Zsearch in a state where the contact state cannot be detected, the change of the target position is stopped and the moving stage 9
To stop the δz search operation.

Therefore, according to the present embodiment, the movable distance of the moving stage 9 when searching for a position where the output of the stylus probe 1 can be switched to the position control is set to the predetermined distance Z.
By limiting to the search, the stylus probe 1 and the test object 1 which are generated when the position where the output of the stylus probe 1 has a predetermined value cannot be detected for some reason.
It is possible to prevent the destruction due to the collision of 0.

The sixth embodiment of the present invention will be described with reference to FIG.

In the operation of determining that the stylus probe 1 has come into contact with the surface of the object to be inspected 10 as described above, or in the operation of searching for the vicinity of the load equivalent target position δzref, the output δz of the stylus probe 1 is selected. Normal operation may not be possible due to the addition of noise or disturbance.
Therefore, since the moving stage 9 continues to move, there is a possibility that the stylus probe 1 and the test object 10 collide and are destroyed, or abnormal operation continues.

Therefore, in this embodiment, the time during which such an operation is performed is limited to a predetermined time. If the contact determination or the vicinity of the load-equivalent target position δzref cannot be found even after the lapse of a predetermined time, the moving stage 9 is stopped and the above operation is ended.

Such operation control will be described with reference to FIG. In the δz search operation, the moving stage 9 is driven in the negative direction by changing the target position in the negative direction. In normal operation, the contact of the stylus probe 1 is determined by the operation as in each of the above-described embodiments, and the vicinity of the load equivalent target position δzref is searched, but the output δz of the stylus probe 1 is determined after the contact state determination. The vicinity of the load-equivalent target position δzref cannot be searched due to noise and disturbance to the moving stage 9, and the moving stage 9 continues to be driven in the positive direction. When the δz search operation has passed a predetermined time Tsearch in a state where the vicinity of the load equivalent target position δzref cannot be searched, the change of the target position is stopped, the moving stage 9 is stopped, and the δz search operation is ended.

Therefore, according to the present embodiment, by limiting the search time when searching for a position that can be switched to the position control using the output of the stylus probe 1, to the predetermined time Tsearch, the stylus probe is obtained. It is possible to appropriately deal with the case where the position where the output of 1 has a predetermined value cannot be detected.

The seventh embodiment of the present invention will be described with reference to FIGS. 14 to 16.

First, by the operation of each of the above-described embodiments, the position control is switched to the output signal δz of the stylus probe 1, and the stylus probe 1 is in contact with the surface of the object 10 with a predetermined load. The state is shown in FIG. Due to disturbances such as noise and vibration applied to the stylus probe 1, FIG.
As indicated by the signal .delta.z shown in FIG. In order to reduce the deviation during tracking, it is necessary to increase the gain of the position control system, but in actual devices there is a limit to the increase in gain due to mechanical resonance and the performance of the computing unit, and it is also possible to reduce deviation. There is a limit. Further, the occurrence of the tracking deviation is equivalent to the fluctuation of the contact load. Depending on the object to be inspected 10, the allowable value of the fluctuation of the contact load may be small.

Therefore, in this embodiment, when the output signal δz of the stylus probe 1 is out of the predetermined range ± δzlim with respect to the load-equivalent target position δzref, the mode switching switch 22 is set to A and the switch 23 is set. Is switched to B to return to the position control mode by the output signal z of the linear encoder 13. The position control based on the output signal δz of the stylus probe 1 is possible when the output is expressed by the equation δz = δzref ± δzlim (3).

That is, in this embodiment, the operation control as shown in the flowchart of FIG. 15 is performed.
In the load control mode (S15), it is determined whether or not the absolute value of the output δz of the stylus probe 1 is larger than the absolute value of δzlim which is a predetermined value (S16). If it is smaller, the process returns to step S15 to continue the load control mode based on δz. If it is larger (Y in S16), the mode is switched to the position control mode using the linear encoder 13 (S1).
7). The processing of step S16 is executed as a function of the determination means, and when the predetermined range δzref ± δzlim is exceeded, the mode is returned to the position control mode.

Therefore, according to the present embodiment, in the position control based on the output of the stylus probe 1, when the output of the stylus probe 1 exceeds the predetermined range δzref ± δzlim, the stylus probe 1 Since the load control mode based on the output of the linear encoder 13 is switched to the position control mode based on the position signal of the linear encoder 13, an abnormal load is generated and the stylus probe 1 or the test object 10 is destroyed, It is possible to prevent the stylus probe 1 from coming into a non-contact state and making the control device unstable.

By the way, in the case of the present embodiment, in the position control based on the output signal δz of the stylus probe 1,
It is preferable to change the range of the value of the predetermined set load according to the operation mode of the contact load control device. That is, the value of δzlim shown in FIG. 14 is changed according to the device operation mode.

FIG. 16 shows an example of the operation mode.
16A shows a case where the stylus probe 1 is in contact with a flat surface with a constant load, and FIG. End face 10e
There is a case where the position of is detected. In the operation mode in which the position of the end face 10e is detected as shown in FIG. 16B, the output signal z of the linear encoder 13 is used at the moment when the stylus probe 1 is disengaged at the end face 10e in consideration of safety such as collision prevention. It is necessary to switch to position control. In order to facilitate switching to the position control by the output signal z of the linear encoder 13, the value of δzlim is set to a small value as compared with the case of FIG. 16 (a).

In this way, the range of the predetermined value of the output of the stylus probe 1 for switching to the position control based on the position signal of the linear encoder 13 is made variable according to the operating conditions of the device. Thus, it is possible to provide a contact load control device capable of performing a safe operation according to the operating conditions of the device.

The eighth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the contact load control device according to each of the above-described embodiments is mounted, and the stylus probe 1 in contact with a predetermined load is scanned to measure the surface shape of the test surface of the test object 10. An example of application to a shape measuring device is shown.

In this shape measuring apparatus, a Z-axis moving stage 32 that is driven in the vertical direction is mounted on an X / Y-axis moving stage 31. The Z-axis moving stage 32 corresponds to the moving stage 9, and the stylus probe 1 is mounted on the Z-axis moving stage 32. An optical displacement gauge is mounted here as the displacement gauge 8 for detecting the minute displacement δz of the stylus probe 1. Further, an X-axis laser length measuring device 33, a Y-axis laser length measuring device 34, and a Z-axis laser length measuring device 35 are mounted on the Z-axis moving stage 32 in order to detect the displacement of the moving stage. There is. Reference numeral 36 is a reference mirror for the X-axis laser length measuring device 33, 37 is a reference mirror for the Y-axis laser length measuring device 34, and 38 is a reference mirror for the Z-axis laser length measuring device 35.

Next, the operation of the shape measuring apparatus will be described. X
Although not shown, the Y-axis position is detected by a rotary encoder on the motor shaft or a linear encoder arranged on the X / Y moving stage 31, and a position control system using the value of this position is used for the X / Y axis. Is driven. Z
The position of the shaft is detected by the linear encoder 13 and driven by the position control system using this value.

The stylus probe 1 is brought into contact with the test object 10 mounted on the test object mounting jig 39 through the speed control mode and the position control mode as described above, and the displacement δzref corresponding to a predetermined load is applied. At this point, the Z-axis control is switched to a follow-up control system (load control mode) using the output of the displacement gauge 8 so that the output of the displacement gauge 8 becomes a predetermined value.
In this Z-axis follow-up control state, the X-axis or Y-axis moving stage is driven to scan the object 10 to be inspected. The locus at this time is detected by the three-axis laser length measuring devices 33, 34, and 35 provided on the Z-axis moving stage 32, and the value is used as the surface shape of the test surface of the test object 10. This is the principle of the shape measuring device.

According to this embodiment, since the load control device as in each of the above-described embodiments is mounted, a shape measuring device having a wide dynamic range and capable of measuring a highly accurate shape under a low load is provided. Can be provided.

The ninth embodiment of the present invention will be described with reference to FIG. In this embodiment, the contact load control device according to each of the above-described embodiments is mounted, and the stylus probe 1 is used to control the output of the stylus probe 1 to a predetermined value.
An example of application to a robot that performs follow-up control (compliance control) along a 0 surface shape to be inspected will be described.

The tip of the robot arm 41 is provided with the stylus probe 1 having the above-described structure. The robot arm 41 operates similarly to the moving stage 9. In the speed control mode, speed control is performed based on the speed signal calculated from the encoder signal of the motor for each axis, and the robot moves to the position to be positioned at high speed. Switch to the position control mode by the encoder near the predetermined position,
Position control is performed based on the encoder signal of the motor for each axis. The stylus probe 1 is brought into contact with the surface of the object to be inspected 10, and the robot arm 41 is controlled so that the output of the displacement gauge 8 mounted on the stylus probe 1 becomes the target position corresponding to the contact load. The robot arm 41 is controlled so that the output of the displacement meter 8 is set at the target position corresponding to the contact load, and the surface of the test object 10 is followed. The coordinate locus of the tip of the robot arm 41 at this time can be the surface shape of the test object 10.

The contact with a low load does not deform or damage the test object 10. The acquired shape data can be used as coordinates for teaching the robot arm 41. As an application, the robot arm 41 has a welding function at the tip thereof, and a copying operation using the taught coordinates,
By performing a real-time copying operation using the stylus probe 1, the robot arm 41 can be made to follow the surface of the object 10 to be welded.

The tenth embodiment of the present invention will be described with reference to FIGS. 19 to 25. The control device of the present embodiment shows an application example to an automatic focus control device, and an optical displacement meter 51
Is built in, and a focus signal is output as a probe output based on the output of the light receiving element of the optical displacement meter 51, and the object to be inspected 10
The non-contact type probe 52 facing the surface to be inspected is used.

First, the optical displacement meter 51 will be described. In this embodiment, the astigmatism method is used as a typical example, which will be described with reference to FIGS. 20 to 22. In FIG. 20, the light emitted from the semiconductor laser 53 passes through the polarization beam splitter 54 and the objective lens 55.
Is condensed on the surface to be inspected, and the reflected light is again reflected by the objective lens 55,
It passes through the polarization beam splitter 54 and further the cylindrical lens 56.
The light then enters the four-division photodiode 57 as a light receiving element.

FIG. 21 shows the four-divided photodiode 57 and the beam spot shape formed on the light receiving surface thereof.
When the surface to be inspected is at the focal position of the objective lens 55, adjustment is made so that a circular beam spot is formed on the four-division photodiode 57 (FIG. 21B). When the surface to be inspected is far, FIG. 21A, a horizontally long elliptical beam is formed, and when the surface to be inspected is close, a vertically long elliptical beam is formed as shown in FIG. Therefore, assuming that the outputs of the respective regions of the four-division photodiode 57 are a, b, c and d, S = {(a + c)-(b + d)} / (a + b + c + d) (4) The focus error signal S Is obtained.

As shown in FIG. 22, the focus error signal S calculated from the equation (4) is positive when the surface to be inspected is far, zero at the just focus position, and negative when the surface to be inspected is near. Becomes It should be noted that the reason for dividing by the total amount of received light in the equation (4) is to prevent the influence of the reflectance of the surface to be measured. In the present embodiment, a signal obtained by multiplying the focus error signal S by a predetermined value and converting it into a distance will be referred to as a focus signal xf.

Next, the structure of the automatic focus control device equipped with the non-contact type probe 52 with the built-in optical displacement gauge 51 and the control circuit thereof will be described with reference to FIG. Although the basic configuration is the same as that shown in FIG. 1, since the non-contact type probe 52 is used instead of the stylus type probe 1, the focus signal xf is used instead of δz as the probe output, As the position information by the linear encoder 13, x is used instead of z, and as the target position information, the focus target position is used instead of the load-equivalent target position.

The operation modes of the automatic focus control device according to the present embodiment having such a configuration will be described.

<Speed control mode> Linear encoder 13
The velocity v is calculated by the velocity calculator 16 from the position x information of the moving stage 9 detected by. The calculated speed v and the target speed set by the mode switching controller 24 are input to the comparator 17 to calculate the speed deviation ev. The speed deviation ev is input to the speed control compensator 18, and the manipulated variable ic corresponding to the speed deviation is output. Here, the manipulated variable is set to the target current value ic. The target current value ic is input to the motor driver 14, and the motor current im is supplied to the voice coil motor 12 to drive the moving stage 9 in the vertical direction by speed control.

<Position Control Mode by Encoder> The position x of the moving stage 9 detected by the linear encoder 13 and the target position set by the mode switching controller 24 are input to the comparator 19 and the position deviation ex is calculated. The position deviation ex is input to the position control compensator 20 and an operation amount ic corresponding to the position deviation is output. Here, the manipulated variable is set to the target current value ic. The target current value ic is input to the motor driver 14, and the motor current im is supplied to the voice coil motor 12 to drive the moving stage 9 in the vertical direction by position control.

<Position control mode by probe signal> The focus signal xf corresponding to the displacement focus error signal and the mode switching controller 24 when the distance between the optical displacement meter 51 and the surface of the object 10 is out of focus. Information about the focus target position to be set is provided by the comparator 21.
And the position deviation ex is calculated. The position deviation ex is input to the position control compensator 20, and the manipulated variable ic corresponding to the position deviation ex is output. Here, the manipulated variable is set to the target current value i
Let be c. The target current value ic is input to the motor driver 14 to cause the motor current im to flow through the voice coil motor 12 to drive the moving stage 9 in the vertical direction by position control by the focus signal xf.

An example of operation control using these operation modes during the focus pull-in operation will be described with reference to FIG.

In FIG. 23, the case where the moving stage 9 moves upward is the positive direction, the case where the moving stage 9 moves downward is the negative direction, and the tip of the objective lens 55 of the optical displacement meter 51 is used as the position reference. explain.

In the focus pull-in operation, the mode switching switch 22 shown in FIG. 19 is switched to A and the objective lens 55 is moved from the initial position to the focus pull-in start position in the positive direction from the focus pull-in position in the speed control mode. The moving direction by this speed control can be positive or negative depending on the initial position of the moving stage 9.

Next, the switch 22 for mode switching is set to A
Then, switch the switch 23 to B, and the linear encoder 1
The position control mode according to 3 is performed. The target position is changed in the negative direction and the moving stage 9 is moved in the direction of approaching the object 10.

In parallel with the position control by the linear encoder 13, the focus signal xf based on the signal obtained from the four-division photodiode 57 is constantly observed, and when the focus pull-in range shown in FIG. Switch 22 of switch to B (switch 2
3 remains B), and the position control mode by the focus signal xf is executed. The focus target position at this time is 0, which is the in-focus position. In the position control by the focus signal xf, the position control is always performed so that the deviation of the focus signal becomes zero.

An example of such operation mode control executed by the mode switching controller 24 will be described with reference to the flowchart shown in FIG. First, the moving stage 9
Is stopped, it is stopped at an arbitrary position by the position control mode shown in step S21. Then, it is determined at any time whether or not switching to the focus pull-in operation mode (following control mode) by the focus signal xf is designated (S22). When switching to the focus pull-in operation mode is designated (Y in S22), switch 2
3 is switched to shift to the speed control mode and move to a predetermined position (focus pull-in start position) (S23).
The process of step S23 is executed as a speed control mode execution means or a speed control mode execution step.

When it is determined in this speed control mode that the camera has moved to a predetermined position (focus pull-in start position) (Y in S24), the encoder position control mode is switched by switching the switches 22 and 23 (S25). In this encoder position control mode, the moving stage 9 is moved minutely by changing the target position little by little in the minute feed mode (S26). The processing of these steps S25 and S26 is executed as a position control mode execution means or a position control mode execution step.

In the processing of the encoder position control mode, whether or not the focus signal xf has reached the focus pull-in position is determined at any time (S27). When the focus pull-in position is reached and switching is possible (Y in S27),
The target position in the position control mode is set to the focus target position, and the switch 22 is switched to switch the position detecting means to the focus signal xf, thereby executing the focus pull-in operation mode which is the focus position control mode (S2).
8). The process of step S28 is executed as the follow-up control mode executing means or the follow-up control mode executing step.

Therefore, according to the present embodiment, basically, not only the position control system by the position control compensator 20 but also the speed control system by the speed control compensator 18 is mounted, so that the optical displacement gauge 51 It is possible to move the moving stage 9 equipped with a high speed, and a stable focus pull-in operation is possible in a short time with a wide operation range. In particular, by sequentially switching the speed control mode, the position control mode, and the follow-up control mode according to the operating condition, the focus pull-in operation time can be reduced even when the movable stage 9 having the optical displacement meter 51 has a wide operation range. It can be shortened.

The eleventh embodiment of the present invention will be described with reference to FIGS. 26 and 27. The form of this embarrassment is basically similar to that of the tenth embodiment, and in the focus pull-in operation, the mode switching switch 2 of FIG.
2 is switched to A and the objective lens 55 is moved from the initial position to the focus pull-in start position in the negative direction of the focus pull-in position by the speed control mode. The moving direction in this speed control mode can be positive or negative depending on the initial position of the carriage.

Next, the switch 22 for mode switching is set to A
Then, switch the switch 23 to B, and the linear encoder 1
The position control mode according to 3 is executed. The target position is changed in the positive direction and the moving stage 9 is moved in the positive direction. The focus signal xf shown in FIG. 27 is constantly monitored in parallel with the execution of the position control mode by the linear encoder 13, and when the focus retractable range shown in FIG. 27 is reached, the mode switching switch 22 is switched to B. , A position control mode by the focus signal xf, that is,
The focus pull-in operation mode is executed. The focus target position at this time is 0, which is the in-focus position. In the control of the focus pull-in operation mode by the focus signal xf, position control is performed so that the deviation of the focus signal is always zero.

Therefore, according to the present embodiment, basically the same effect as in the tenth embodiment can be obtained,
In particular, by setting the direction of the focus retraction operation away from the object 10 to be inspected, the focus retraction can be performed in a short time, and at the same time, the object 10 collides with the surface to be inspected and the optical displacement meter 51 or the object to be inspected. It is possible to provide an automatic focus control device that does not destroy the object 10 or the non-contact type probe 52 to which the optical displacement meter is applied.

The twelfth embodiment of the present invention will be described with reference to FIG. The present embodiment is based on, for example, the tenth embodiment described above, and as described above, the focus pull-in position is searched from the focus pull-in start position by the position control mode by the linear encoder 13. However, the accuracy of the surface to be inspected of the object to be inspected 10 or the adherence of dust may cause the laser light emitted from the optical displacement meter 51 to be irregularly reflected, and the focus signal xf may not be normally detected.

Therefore, in the present embodiment, when the focus pull-in position cannot be detected by scanning a predetermined focus search distance from the focus pull-in start position, the moving stage 9 is stopped and the non-contact type probe 52 (objective). The lens 55) can be prevented from colliding with the object 10 to be inspected.

As described above, according to the present embodiment, by limiting the feed distance (focus search distance) of the moving stage 9 during the focus pull-in operation to a predetermined distance,
It is possible to prevent the collision with the object to be inspected 10 and to detect the fact that the focus cannot be pulled in at an early stage, and to provide an automatic focus control device with improved safety.

The thirteenth embodiment of the present invention will be described with reference to FIG. In this embodiment, in the tenth to twelfth embodiments, the shift to the focus pull-in operation is restricted.

The total received light amount ALL obtained by the four-divided photodiode 57 is obtained as ALL = a + b + c + d (5). Therefore, the focus signal xf calculated based on the equation (4) and the total received light amount ALL of the four-divided photodiode 57 obtained by the equation (5) are constantly monitored, and the focus signal xf is within the focus pullable range. And the total received light amount ALL is P in FIG.
When it is larger than the predetermined value shown as the D total received light amount threshold level, the mode switching switch 22 is switched to B to shift to the focus pull-in operation mode by the focus signal xf.

As a result, according to the present embodiment, the method and structure of the optical displacement meter 51 are different, and the photodiode 5
Even if there are some zero-cross points in the focus signal xf due to differences in the method of calculating the focus signal xf from the seven outputs, by adding the total received light amount ALL of the four-division photodiode 57 to the focus pull-in determination, Focus can be drawn to the correct zero-cross point.

By the way, in the case of the present embodiment, the focus signal xf is within the focus pull-in range, and the total received light amount ALL of the 4-division photodiode 57 is higher than the PD total received light amount threshold level which is a predetermined value. If the high state continues for a predetermined time or more, the mode switching switch 22 is switched to B to shift to the focus pull-in operation mode by the focus signal xf. A correct focus pull-in can be performed by suppressing a malfunction caused by a noise component generated.

In the case of the present embodiment, the total received light amount ALL of the four-divided photodiode 57 is passed through the low-pass filter 58 as shown in FIG.
The noise component included in LL is removed, and the focus signal x
When f is within the focus pull-in range, and the total PD received light amount ALL 'that has passed through the low-pass filter 58 is larger than the predetermined PD total received light amount threshold level, the mode switching switch 22 is set to B. By switching to shift to the focus pull-in operation mode by the focus signal xf, correct focus pull-in can be performed while suppressing malfunction due to noise components included in the PD total received light amount ALL. Further, by changing the cutoff frequency of the low pass filter 58, it is possible to adjust the signal characteristic required for the pull-in.

A fourteenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, changes in the focus signal xf are constantly monitored (output change monitoring means) during execution of the focus pull-in operation mode, and the focus signal xf is monitored.
The focus pull-in operation is performed by using the detection of the tilt direction associated with the change of as the determination material.

First, according to the above-described embodiment, the moving stage 9 is moved to the focus pull-in start position in the speed control mode. Next, the switch 22 for mode switching is switched to A and the switch 23 is switched to B, and the position control mode by the linear encoder 13 is executed. In this position control mode, the target position is changed in the negative direction and the moving stage 9 is moved in the direction approaching the object 10. In parallel with the execution of the position control mode by the linear encoder 13, the focus signal xf as shown in FIG.
Is constantly monitored, and when the focus retractable range shown in FIG. 31 is entered and the inclination of the focus signal xf is a predetermined inclination (negative inclination in this case), the mode switching switch 22 Is switched to B to shift to the focus pull-in operation mode by the focus signal xf.

When the optical displacement meter 51 is used, if the focus inclination (change in focus signal with respect to the distance) at the zero-cross point where the focus pull-in is performed is the opposite inclination, the control system may oscillate. However, it is possible to provide an automatic focus control device that enables a reliable focus pull-in operation by adding the inclination of the focus signal xf to the determination as in the present embodiment.

By the way, in the case of the present embodiment, the focus signal xf as shown in FIG. 31 is constantly monitored in parallel with the execution of the position control mode by the linear encoder 13, and the focus pull-in range shown in FIG. 31 is entered. ,And,
When the tilt of the focus signal xf is a tilt in a predetermined direction (here, a negative tilt) and the tilt state continues for a predetermined time or more, the mode switching switch 22 is switched to B, and the focus signal xf By shifting to the focus pull-in operation mode based on xf, it is possible to suppress malfunction due to noise components included in the focus signal xf, and to perform stable focus pull-in.

When the determination condition is that the inclination in the predetermined direction continues for a predetermined time, the focus inclination is monitored for a predetermined time to detect the retractable state in the case where the speed of the focus retraction operation is fast. Then, the optimal focus pull-in point may have already been passed. In that case, by moving the target position in the positive direction, the moving stage 9 is driven in the reverse direction to move to the optimum focus pull-in point, as shown in FIG.
The switch 22 for mode switching may be switched to B to shift to the focus pull-in operation mode by the focus signal xf.

On the contrary, when the speed of the focus pull-in operation is slow, the optimum focus pull-in point may not be reached even if the tiltable state is detected by monitoring the tilt of the focus for a predetermined time. . In that case, if the target position is continuously changed in the negative direction to move to the optimum focus pull-in point, the mode switching switch 22 is switched to B, and the focus pull-in operation mode is switched by the focus signal xf. Good.

That is, there are cases where the focus pull-in point (in this case, it is considered as a zero cross point) has not been reached or when the optimum focus pull-in point has been passed by adding a temporal judgment. , It is possible to pull in the focus because it is within the focus pull-in range, but when the focus is pulled in, the position control system instantaneously moves to the zero cross point, and when the gain is high, overshoot occurs greatly and attenuates. It may take some time, but during the focus pull-in operation, make sure that the focus signal has a pull-in value and the focus signal xf has a predetermined tilt for a predetermined time or longer. If the current position at that time has not reached the focus pull-in point, focus pull-in is performed. Continue to look for, in the case where the focus pull-in point they've already passed, the moving stage 9
The problem can be solved by driving the lens in the opposite direction to move to the focus pull-in point, and then performing the focus pull-in.

Further, in the case of the present embodiment, in parallel with the execution of the position control mode by the linear encoder 13, FIG.
As shown in FIG. 3, the focus signal xf ′ that has passed through the low-pass filter 59 is constantly monitored to enter the focus retractable range shown in FIG. 31, and the focus signal xf ′ has a predetermined slope (here, If the inclination is negative, the mode switching switch 22 is switched to B so as to shift to the focus pull-in operation mode by the focus signal xf, so that a malfunction due to a noise component included in the focus signal xf may occur. Stable focus pull-in is possible by suppressing. Further, by changing the cutoff frequency of the low-pass filter 59, it is possible to adjust the signal characteristic required for the pull-in.

The fifteenth embodiment of the present invention will be described with reference to FIG. The present embodiment is provided with a feed speed changing means according to the fourth embodiment, and during focus pull-in operation, position control for moving to a position where focus pull-in is possible by a position detection signal from the linear encoder 13 of the moving stage 9. In the operation, the feed speed Vp1 of the actuator until the focus retractable range is detected,
By changing the feed speed Vp2 of the moving stage 9 until the focus pull-in point is detected, | Vp1 |> | Vp2 |
It is designed to be The function of the feed rate changing means is executed by the mode switching controller 24.

As described above, the moving stage 9 is moved to the focus pull-in start position in the speed control mode. Next, the switch 22 for mode switching is switched to A and the switch 23 is switched to B, and the position control mode by the linear encoder 13 is executed. In this position control mode, the target position is changed in the negative direction at a feed speed of | Vp1 |, and the moving stage 9 is moved in a direction approaching the object 10. In parallel with the execution of the position control mode by the linear encoder 13, the focus signal x shown in FIG.
f is constantly monitored, and the focus pullable range shown in FIG. 34 is searched. When the focus pull-in range is entered, the feed speed changing means changes the change speed of the target position to | Vp2 | in the relationship of | Vp1 |> | Vp2 | to reduce the feed speed of the moving stage 9, and then to focus. Search for the point of attraction. When the focus pull-in point is reached (here, at the zero-cross point), the mode switching switch 22 is switched to B to shift to the focus pull-in operation mode by the focus signal xf.

As described above, according to the present embodiment, the feed speed Vp1 for searching the focus pull-in range where the focus pull-in is effective and the feed speed Vp2 for searching the focus pull-in point as the zero cross point are changed. By doing so, it is possible to change the deviation between the target position and the actual position that occur during movement. When the focus pull-in range is searched, the speed of Vp1 is set large and the position deviation is large to shorten the search time. When searching the focus pull-in point, the speed of Vp2 is set small and the position deviation is set small to reduce the focus pull-in search accuracy. And improve stopping accuracy. This makes it possible to shorten the focus pull-in time and perform a stable focus pull-in operation.

The sixteenth embodiment of the present invention will be described with reference to FIG. In the present embodiment, when the focus pull-in operation is performed using the optical displacement meter 51, when the focus signal xf reaches the pull-in position, the target value of the position control by the focus signal xf (focus target value). To the value of the focus signal at that time and switch to position control by the focus signal (focus is pulled in), and then change the target value to change the focus target value to the original target value of the position control by the focus signal xf. It is equipped with means. The function of the target value changing means is executed by the mode switching controller 24.

As in each of the above-described embodiments using the optical displacement meter 51, first, the moving stage 9 is moved to the focus pull-in start position in the speed control mode. Next, the switch 22 for mode switching is set to A, and the switch 2
3 is switched to B, and the position control mode by the linear encoder 13 is executed. In this position control mode, the target position is changed in the negative direction to move the moving stage 9 to the object 1
Move it toward 0. Linear encoder 1
35, the focus signal xf shown in FIG. 35 is constantly monitored in parallel with the execution of the position control mode, and when the focus retractable range shown in FIG. 35 is entered, the focus target position is changed to the current focus signal value. Switch to the mode switching switch 22B, and the focus signal x
The position is controlled by f. After that, the focus target position is changed to the original focus target position (here, the zero cross point) to complete the focus pull-in operation.

As described above, according to the present embodiment, by changing the focus target position, the positional deviation at the moment of pulling in the focus can be minimized, and the focus can be stably pulled in stably.

Although not particularly shown, the optical displacement gauge 5
The automatic focus control device according to each of the embodiments using No. 1 can also be used for the shape measuring device as in the case shown in FIG.

[0175]

According to the control device of the present invention, not only the position control system by the position control compensator but also the speed control system by the speed control compensator is mounted. High-speed movement is possible,
Even if the operating range is wide, it can be positioned at a predetermined position in a short time.

According to the invention described in claim 2, in the control device according to claim 1, the speed control mode, the position control mode and the follow-up control mode are switched in a predetermined order. High-speed movement is possible, and even if the operating range is wide, it can be positioned at a predetermined position in a short time, and it can be brought into contact with a predetermined load without colliding with the surface of the test object and destroying the probe or the test object. can do.

According to the third aspect of the present invention, in the control device according to the second aspect, the probe feed speed is changed by changing the feed speed of the actuator when searching for a position at which the probe output can be switched to the follow-up control mode. It is possible to achieve both high-speed state determination and high-precision predetermined switching position detection, and high-speed and high-precision switching to the tracking control mode by the probe output.

According to the invention described in claim 4, in the control device according to claim 2 or 3, when the output of the probe exceeds a predetermined range, the position of the position detector is changed from the tracking control mode based on the probe output. By switching to the position control mode based on the signal, it is possible to prevent the probe and the object to be inspected from being destroyed and the control of the probe from becoming unstable.

According to the fifth aspect of the invention, in the control device of the fourth aspect, the predetermined range for switching to the position control mode based on the signal of the position detection section is variable according to the operating conditions of the device. By setting, it is possible to ensure safe operation according to the operating conditions of the device.

According to the invention described in claim 6, in the control device according to claim 1, the control mode is the speed control mode,
Since the position control mode and the follow-up control mode are switched in a predetermined order, it is possible to move the actuator equipped with the contact type probe at high speed, and perform positioning to a predetermined position in a short time even if the operating range is wide, The contact state with a predetermined load can be achieved without colliding with the inspection surface and destroying the contact-type probe or the test object.

According to the invention described in claim 7, in the control device according to claim 6, it is determined that the contact with the surface to be inspected is made by detecting the inclination of the output of the contact type probe. The contact state with a predetermined load can be achieved.

According to the eighth aspect of the present invention, in the control device according to the first aspect, the optical displacement meter is changed by sequentially switching the speed control mode, the position control mode and the follow-up control mode as control modes. Even when the operating range of the mounted actuator is wide, the focus pull-in operation time can be shortened.

According to the invention of claim 9, the same effect as that of the invention of claim 8 can be obtained, but in particular, by setting the direction of the focus retraction operation away from the object to be inspected, the focus retraction is performed. It is possible in a short time, and it is possible to prevent the optical displacement meter or the object to be inspected or the probe to which the optical displacement meter is applied from being collided with the surface to be inspected.

According to the invention of claim 10, claim 8 is provided.
Alternatively, in the control device according to the ninth aspect, a feed distance (focus search distance) of the actuator during focus pull-in operation
By limiting the distance to a predetermined distance, it is possible to prevent a collision with the object to be inspected, and it is possible to detect that the focus cannot be retracted at an early stage, and it is possible to enhance safety.

According to the eleventh aspect of the invention, in the control device of the eighth, ninth or tenth aspect, there is a difference in the method or configuration of the optical displacement gauge, a difference in the method of calculating the focus signal from the light receiving element output, etc. There may be some zero cross points in the focus signal due to the focus signal, and it is possible to pull the focus to the wrong zero cross point during the focus pull-in operation.However, by adding the total amount of light received by the light receiving element to the focus pull-in determination, The focus pull-in operation can be performed stably.

According to the twelfth aspect of the invention, in the control device according to the eighth, ninth, tenth or eleventh aspect, the focus inclination (change of the focus signal with respect to the distance) at the zero-cross point where the focus pull-in is performed is opposite. If it is tilted, the control system may oscillate, but by adding the tilt direction of the focus signal to the determination, the focus pull-in operation can be reliably performed.

According to the invention of claim 13, claim 1
In the control device according to the second aspect, since the inclination of the focus signal can be observed in time series by adding a temporal determination, it is possible to suppress malfunction due to a noise component included in the focus signal.

According to the fourteenth aspect of the present invention, in the control device of the eighth, ninth, tenth, eleventh, twelfth or thirteenth aspect, the focus deviation is minimized by changing the focus target position. As a result, it is possible to stably pull in the focus.

According to the control method of the invention as set forth in claim 15, since the speed control mode, the position control mode, and the follow-up control mode are switched in a predetermined order, the actuator equipped with the probe can be moved at high speed. Even if the operating range is wide, positioning can be performed at a predetermined position in a short time, and the probe and the test object can be brought into contact with each other with a predetermined load without colliding with the surface of the test object and destroying the probe and the test object.

According to the sixteenth aspect of the control method of the present invention, the control modes are switched in a predetermined order of the speed control mode, the position control mode, and the follow-up control mode. It is possible to move and position it at a predetermined position in a short time even if the operating range is wide, and it is in a contact state with a predetermined load without colliding with the surface to be inspected and destroying the contact probe or the object to be inspected You can

According to the control method of the seventeenth aspect of the present invention, the operating range of the actuator equipped with the optical displacement gauge is controlled by sequentially switching the control mode in the order of the speed control mode, the position control mode and the follow-up control mode. Even in a wide range, the focus pull-in operation time can be shortened.

According to the control method of the invention described in claim 18, the same effect as that of the invention described in claim 17 can be obtained.
In particular, by making the direction of focus retraction operation away from the object to be inspected, focus retraction can be performed in a short time, and an optical displacement meter or object or optical displacement meter is applied by colliding with the surface to be inspected. It is possible to prevent the destroyed probe from being destroyed.

According to the shape measuring apparatus of the nineteenth aspect of the present invention, by mounting the control apparatus according to any one of the first to fourteenth aspects on the shape measuring apparatus, a wide dynamic range and a high load under a low load can be obtained. A shape measuring device capable of measuring an accurate shape can be provided.

According to the robot of the invention described in claim 20, by mounting the control device according to any one of claims 1 to 8 on the robot, the dynamic range is wide and damage to the surface to be inspected can be prevented. Compliance control can be performed with a predetermined load under a low load.

[Brief description of drawings]

FIG. 1 is a cross-sectional structure diagram of a stylus probe showing a first embodiment of the present invention.

FIG. 2 is a block configuration diagram mainly showing a control system.

FIG. 3 is a schematic diagram showing a contact operation of a stylus probe.

FIG. 4 is a schematic flowchart showing an example of operation control.

FIG. 5 is a characteristic diagram of a probe output showing a second embodiment of the present invention.

FIG. 6 is a schematic flowchart showing an example of the operation control.

FIG. 7 is a characteristic diagram of a probe output showing a third embodiment of the present invention.

FIG. 8 is a schematic flowchart showing an example of operation control.

FIG. 9 is a characteristic diagram of a probe output showing a modified example.

FIG. 10 is a characteristic diagram of a probe output showing a fourth embodiment of the present invention.

FIG. 11 is a schematic flowchart showing an example of operation control.

FIG. 12 is a probe output characteristic diagram showing the fifth embodiment of the present invention.

FIG. 13 is a characteristic diagram of a probe output showing a sixth embodiment of the present invention.

FIG. 14 is a characteristic diagram of a probe output showing a seventh embodiment of the present invention.

FIG. 15 is a schematic flowchart showing an example of operation control.

FIG. 16 is a schematic front view showing an application target example of an operation mode.

FIG. 17 is a schematic configuration diagram showing a shape measuring device according to an eighth embodiment of the present invention.

FIG. 18 is a schematic configuration diagram showing a robot according to a ninth embodiment of the present invention.

FIG. 19 is a block configuration diagram mainly showing a control system of an automatic focus control device according to a tenth embodiment of the present invention.

FIG. 20 is a principle configurational diagram showing an optical displacement meter.

FIG. 21 is a principle configuration diagram showing a detection principle of a focus error signal.

FIG. 22 is a characteristic diagram showing a focus error signal.

FIG. 23 is a schematic diagram showing a focus pull-in operation of the optical displacement meter.

FIG. 24 is a characteristic diagram showing how the focus signal changes with the focus pull-in operation.

FIG. 25 is a schematic flowchart showing an example of operation control.

FIG. 26 is a schematic diagram showing a focus pull-in operation of the optical displacement meter of the eleventh embodiment of the present invention.

FIG. 27 is a characteristic diagram showing how the focus signal changes with the focus pull-in operation.

FIG. 28 is a schematic diagram showing a focus pull-in operation of the optical displacement meter of the twelfth embodiment of the present invention.

FIG. 29 is a characteristic diagram showing the relationship between the focus signal and the total amount of received light according to the thirteenth embodiment of the present invention.

FIG. 30 is an explanatory diagram of waveform processing showing a modification thereof.

FIG. 31 is a characteristic diagram showing a focus signal according to a fourteenth embodiment of the present invention.

FIG. 32 is a schematic diagram showing a focus pull-in operation of the optical displacement meter of the modified example.

FIG. 33 is an explanatory diagram of waveform processing showing a modification thereof.

FIG. 34 is a schematic diagram showing a focus pull-in operation of the optical displacement meter of the fifteenth embodiment of the present invention.

FIG. 35 is a schematic view showing the focus pull-in operation of the optical displacement meter of the sixteenth embodiment of the invention.

[Explanation of symbols]

1 Stylus probe, probe 7 spring 9 Actuator 10 object 13 Position detector 14 Drive circuit 18 Speed control compensator 20 Position control compensator 51 Optical displacement meter 52 probe 57 Light receiving element

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 28, 2001 (2001.11.
28)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 17

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction content]

According to a seventeenth aspect of the present invention, in a control method, an optical displacement gauge is built in, a focus signal is output as a probe output based on an output of a light receiving element of the optical displacement gauge, and a non-contact facing a surface to be inspected. An actuator equipped with a probe, a position detector that detects the displacement of the actuator and generates a position signal, a position control compensator that performs position control based on the output of the probe or the position signal, and from the position signal Using the speed control compensator that performs speed control based on the calculated speed signal, and a drive circuit that drives the actuator based on the operation amount from the position control compensator or the speed control compensator, the speed control compensation the actuator by the speed control using the vessel from an initial position to a predetermined position in the vicinity remote from the test surface than the focus pull position The speed control mode execution step of moving the contact type probe and the mode is switched at the time when the contact type probe approaches the predetermined position, and the target position is controlled by the position control compensator based on the position signal by the position detection unit. A position control mode execution step of driving the actuator in a direction approaching the inspection surface to perform a search operation;
The mode is switched when the actuator reaches a position where focus can be pulled in, and the focus signal is set to a predetermined value by position control using the position control compensator based on the focus signal from the optical displacement meter. a follow-up control mode executing step to perform the focus pull-in operation of the actuator is driven, Ru comprising a.

Continued front page    F term (reference) 2F069 AA06 AA66 GG01 GG02 GG04                       HH02 HH09 HH14 LL02 NN26                 3C007 KS17 KS36 KW06 LS01 LT07                       LV23                 5H303 AA10 AA20 BB01 BB03 BB06                       BB08 BB11 CC02 CC03 CC04                       CC10 DD01 DD22 DD25 EE03                       FF04 FF06 FF10 GG11 JJ02                       KK01 KK31 KK37 MM05

Claims (20)

[Claims] 1. An actuator equipped with a probe facing a surface to be inspected, a position detector for detecting a displacement of the actuator and generating a position signal, and position control based on the output of the probe or the position signal. A position control compensator, a speed control compensator that performs speed control based on a speed signal calculated from the position signal, and drives the actuator based on the operation amount from the position control compensator or the speed control compensator. A drive device and a control device. 2. A speed control mode executing means for driving the actuator so that the probe approaches the vicinity of the surface to be inspected by speed control using the speed control compensator, and the probe with respect to the surface to be inspected. The position is switched to a mode when approaching a predetermined position, position control mode executing means for driving the actuator by position control using the position control compensator based on the position signal by the position detector, and the output of the probe is A search operation is performed in which the actuator is driven in the position control mode so as to be in the vicinity of a predetermined value, and the mode is switched when the output of the probe reaches the vicinity of the predetermined value, and the position control compensation based on the output of the probe is performed. The actuator is driven so that the output of the probe becomes a predetermined value by position control using a device. Control apparatus according to claim 1; and a follow-up control mode executing means. 3. An operation of searching for a position where the probe output reaches a predetermined value by the position control mode execution means, includes a first searching operation and a second searching operation, and the actuator feed of the first searching operation. The control device according to claim 2, further comprising a feed speed changing unit that changes the actuator feed speed so that the actuator feed speed in the second search operation becomes slower than the speed. 4. A determination means for determining whether or not the output of the probe exceeds a predetermined range when the actuator is driven by the follow-up control mode execution means, and executes the position control mode when the output exceeds the predetermined range. The control device according to claim 2 or 3, wherein the control is switched to control by means. 5. The control device according to claim 4, wherein the predetermined range is variably set according to operating conditions. 6. The contact probe is a spring-supported contact type probe, and the actuator is driven to a position near the surface to be inspected immediately before the contact type probe comes into contact by speed control using the speed control compensator. The speed control mode executing means, the mode is switched at the time when the contact probe approaches the position near the surface to be detected, and the position control is performed by the position control compensator based on the position signal by the position detection unit. Position control mode executing means for driving the actuator in the direction in which the contact type probe contacts the surface to be inspected and performing a search operation, and switching the mode when the output of the contact type probe reaches a predetermined value, Position control using the position control compensator based on the output of the contact probe so that the output of the contact probe becomes a predetermined value. The control device according to claim 1, further comprising a follow-up control mode executing means for driving the actuator. 7. An output change monitoring means for monitoring a change in the output of the contact type probe when the actuator is driven during a search operation by the position control mode execution means, the output change monitoring means for changing the output of the contact type probe. 7. The control device according to claim 6, wherein a change in the output is detected as an inclination in a predetermined direction, and when the output of the contact type probe reaches the vicinity of a predetermined value, the control is switched to the control by the follow-up control mode executing means. 8. The probe has a built-in optical displacement sensor,
A non-contact probe that outputs a focus signal based on the output of the light receiving element of the optical displacement meter as a probe output, and the surface to be inspected from the initial position to the focus pull-in position by speed control using the speed control compensator. Speed control mode executing means for driving the actuator to a predetermined position in the vicinity of the position, and the mode is switched when the contact-type probe approaches the predetermined position, and the position based on the position signal by the position detection unit is detected. Position control mode executing means for driving the actuator in a direction approaching the surface to be inspected by position control using a control compensator and performing a search operation, and switching the mode when the actuator reaches a position where focus can be pulled in. Using the position control compensator based on the focus signal from the optical displacement meter The focus signal is the control device according to claim 1, further comprising a, a follow-up control mode executing means for causing the focus pull-in operation by driving the actuator to a predetermined value by the position control. 9. The probe has a built-in optical displacement sensor,
A non-contact probe that outputs a focus signal based on the output of the light receiving element of the optical displacement meter as a probe output, and the surface to be inspected from the initial position to the focus pull-in position by speed control using the speed control compensator. Speed control mode executing means for driving the actuator to a predetermined position near the position, and mode switching when the contact probe approaches the predetermined position, and the position control compensation based on the position signal by the position detection unit. Position control mode executing means for performing a search operation by driving the actuator in a direction away from the surface to be inspected by position control using a device, and switching the mode when the actuator reaches a position where focus can be pulled in, Using the position control compensator based on the focus signal by the optical displacement meter Control device according to claim 1, further comprising a tracking control mode executing means for causing the focus pull-in operation the focus signal by location control by driving the actuator to a predetermined value. 10. The control device according to claim 8, wherein a feed distance of the actuator toward a position in which the focus can be retracted when the actuator is driven in the search operation by the position control mode executing means is a predetermined distance. 11. The light receiving element is a light receiving element having a divided structure for detecting a focus signal, and the focus signal has a value capable of pulling the focus when the actuator is driven in the search operation by the position control mode executing means. 11. The control device according to claim 8, 9 or 10, wherein the focus pull-in operation is performed by the follow-up control mode executing means when the total amount of light received by the light receiving element is equal to or greater than a predetermined value. 12. An output change monitoring means for monitoring a change in a focus signal when the actuator is driven in a search operation by the position control mode executing means, wherein the focus signal has a value capable of pulling in focus and the output change 12. The control device according to claim 8, 9, 10 or 11, wherein the follow-up control mode executing means causes the focus pull-in operation when the monitoring means detects a change in the focus signal as an inclination in a predetermined direction. 13. The control device according to claim 12, wherein when the state in which the change of the focus signal is the inclination in the predetermined direction is continuously detected for a predetermined time or more, the follow-up control mode execution means performs the focus pull-in operation. . 14. An output change monitoring means for monitoring a change in a focus signal when the actuator is driven in a search operation by the position control mode executing means, and a follow-up by the focus signal when the focus signal reaches a value capable of pulling the focus. The target value of the control is changed to the value of the focus signal at that time, the follow-up control mode execution means switches to the follow-up control by the focus signal to perform the focus pull-in, and then the target value of the follow-up control by the original focus signal is changed. The control device according to claim 8, 9, 10, 11, 12, or 13, further comprising target value changing means. 15. An actuator equipped with a probe facing a surface to be inspected, a position detector for detecting a displacement of the actuator and generating a position signal, and position control based on the output of the probe or the position signal. A position control compensator, a speed control compensator for performing speed control based on a speed signal calculated from the position signal, and driving the actuator based on the operation amount from the position control compensator or the speed control compensator. Using a drive circuit, a speed control mode execution step of driving the actuator so that the probe approaches the vicinity of the surface to be inspected by speed control using the speed control compensator, and the probe with respect to the surface to be inspected. The position control compensator based on the position signal from the position detection unit when the mode is switched to a predetermined position. A position control mode executing step of driving the actuator by the position control used to perform a search operation, and switching the mode when the output of the probe reaches the vicinity of a predetermined value, and the position control compensator based on the output of the probe. A tracking control mode executing step of driving the actuator so that the output of the probe becomes a predetermined value by position control using. 16. An actuator equipped with a contact probe that is supported by a spring and faces a surface to be detected, a position detector that detects a displacement of the actuator and generates a position signal, an output of the probe or the position signal. A position control compensator for performing position control based on the position signal, a speed control compensator for performing speed control based on a speed signal calculated from the position signal, and an operation amount from the position control compensator or the speed control compensator. And a drive circuit for driving the actuator based on a speed control mode executing step for driving the actuator to a position in the vicinity of the surface to be measured immediately before the contact probe is contacted by the speed control using the speed control compensator. And, when the contact-type probe approaches the position near the surface to be detected, the mode is switched, A position control mode executing step of driving the actuator in a direction in which the contact probe contacts the surface to be inspected by position control using the position control compensator based on a position signal; When the output reaches the vicinity of a predetermined value, the mode is switched, and the actuator is controlled so that the output of the contact probe becomes a predetermined value by the position control using the position control compensator based on the output of the contact probe. And a follow-up control mode executing step of driving the control method. 17. An actuator having a built-in optical displacement gauge, which outputs a focus signal as a probe output based on an output of a light receiving element of the optical displacement gauge, and which is equipped with a non-contact type probe facing a surface to be inspected, A position detection unit that detects a displacement of the actuator and generates a position signal, a position control compensator that performs position control based on the output of the probe or the position signal, and a speed control based on the speed signal calculated from the position signal. And a drive circuit that drives the actuator based on the operation amount from the position control compensator or the speed control compensator, and the initial position is controlled by the speed control using the speed control compensator. From the focus pull-in position to a predetermined position near the surface to be inspected, the speed control mode executing step The mode is switched when the contact probe approaches the predetermined position, and the actuator is moved in a direction away from the surface to be detected by position control using the position control compensator based on the position signal by the position detection unit. And a position control mode executing step of driving the actuator to perform a search operation, and switching the mode when the actuator reaches a position where focus can be pulled in, and using the position control compensator based on a focus signal from the optical displacement meter. A final position tracking control mode execution step of driving the actuator so that the focus signal becomes a predetermined value by position control to perform a focus pull-in operation. 18. An actuator having a built-in optical displacement gauge, which outputs a focus signal as a probe output based on an output of a light receiving element of the optical displacement gauge and which mounts a non-contact type probe facing a surface to be inspected, A position detection unit that detects a displacement of the actuator and generates a position signal, a position control compensator that performs position control based on the output of the probe or the position signal, and a speed control based on the speed signal calculated from the position signal. And a drive circuit that drives the actuator based on the operation amount from the position control compensator or the speed control compensator, and the initial position is controlled by the speed control using the speed control compensator. From the focus pull-in position to a predetermined position near the surface to be inspected, the speed control mode executing step The mode is switched when the contact probe approaches the predetermined position, and the actuator is moved in a direction away from the surface to be detected by position control using the position control compensator based on the position signal by the position detection unit. And a position control mode executing step of driving the actuator to perform a search operation, and switching the mode when the actuator reaches a position where focus can be pulled in, and using the position control compensator based on a focus signal from the optical displacement meter. A tracking control mode executing step of driving the actuator so that the focus signal has a predetermined value by position control to perform a focus pull-in operation. 19. An object to be inspected, comprising the control device according to claim 1, wherein the probe is scanned along the shape of the surface to be inspected while controlling the output of the probe to a predetermined value. A shape measuring device that measures the surface shape. 20. A robot equipped with the control device according to claim 1, wherein the probe follows the shape of the surface to be inspected while controlling the output of the probe to a predetermined value.