Working method of double-measuring-head automatic alignment system based on laser displacement sensor
The application is as follows: 2017.02.17, application No. 201710085083.2, divisional application entitled "dual stylus automatic alignment system based on laser displacement sensor".
Technical Field
The invention relates to a double-measuring-head automatic alignment system based on a laser displacement sensor.
Background
The sensors are various in types and widely applied to various fields of social production and scientific research. The laser displacement sensor is rapidly developed in recent years, and the measuring efficiency and precision are greatly improved in the fields of part size measurement, three-dimensional profile measurement and product quality detection. In some measurement occasions, the method is applied to the double measuring head alignment measurement of the thickness or the diameter of a measured piece.
In general, in the measurement application of the double measuring heads, it is difficult to align the measuring heads on the same straight line, and particularly, a sensor with extremely high accuracy, such as a laser displacement sensor, has higher requirement on the accuracy of alignment, so that the accuracy in measurement can be ensured.
For a laser displacement sensor, in the alignment process, two measuring heads are generally manually adjusted to be aligned, so that a large positioning error exists, the laser displacement sensor is used as a high-precision sensor, and the positioning errors can bring a large influence on a measurement result. In most cases, a laser displacement sensor is fixed, for example, a pre-alignment device is disclosed in a patent of a laser displacement sensor-based and alignment device and system (CN 104635753A), the scheme fixes a laser double-probe, but the alignment problem of the laser double-probe is not considered, and as a system mentioned in a patent of a laser displacement sensor-controlled pre-alignment method, the system relates to the technical field of lithography, and the alignment of a layout center and a mask plate center in the lithography process is solved by using a high-precision platform of an imaging system and the laser displacement sensor, and the adoption of the imaging system means the increase of the manufacturing cost of the system.
And processing the data by adopting a curve fitting method in the control part. So-called curve fitting is from the data set
The general regularity is found out and a curve which can better reflect the general regularity is constructed
. The interpolation method is also a method to deal with such problems, but has significant disadvantages, firstly, because the data inevitably carries errors, this time it requires that the approximation function p (x) crosses all known points, which is equivalent to retaining all errors. In addition, because many experimental data are often obtained, if polynomial interpolation is still adopted, a polynomial with a higher degree is inevitably obtained, so that not only is the calculation complicated, but also the convergence and stability of p (x) are difficult to ensure, a lattice phenomenon occurs, and the approximation effect is poor.
The curve p (x) can be fitted as close as possible to all data points with all errors minimized, so the curve fitting method is a good choice.
Disclosure of Invention
The invention aims to provide a double-measuring-head automatic alignment system based on a laser displacement sensor, which is reliable in precision and convenient to adjust.
The technical solution of the invention is as follows:
a double-measuring-head automatic alignment system based on a laser displacement sensor is characterized in that: the system mainly comprises a mechanical system and a measurement and control system;
the mechanical system comprises a support, a side baffle is arranged at the upper part of the support, an upper mounting plate is arranged at the top of the support, an upper automatic sliding table is mounted on the lower surface of the upper mounting plate, an upper sensor is mounted on the upper automatic sliding table through an upper sensor clamp, a workpiece table arranged on the support is arranged below the upper automatic sliding table, a round hole with the diameter equal to that of a spherical reference object is reserved in the center of the workpiece table, the reference object is placed in the round hole, a lower automatic sliding table mounted on the support is arranged below the workpiece table, and a lower sensor is mounted on the lower automatic sliding table through a lower sensor clamp; the upper sensor and the lower sensor are respectively arranged on the upper side and the lower side of the reference object;
the measurement and control system adopts a motion control card to realize control, and the motion control card controls the upper automatic sliding table and the lower automatic sliding table to move along the X, Y direction through signals given by the upper computer.
The workpiece table is in a form that the workpiece table can be directly drawn out from the bracket.
The sensors move along with the automatic sliding table in the X-Y direction, a curve is fitted by collecting data of finite points, peak points are found, and automatic alignment of the upper sensor and the lower sensor is realized.
Two driving motors for driving the sliding tables to move in the directions x and y which are perpendicular to each other are respectively arranged on the upper automatic sliding table and the lower automatic sliding table.
The working process is as follows:
the first step is as follows: placing a reference object in a workpiece table, and mounting the workpiece table on a bracket;
the second step is that: installing a laser displacement sensor on an automatic sliding table, wherein an upper sensor and a lower sensor are respectively fixed on the upper automatic sliding table and the lower automatic sliding table and are distributed on the upper side and the lower side of a reference object;
the third step: starting a power supply, and enabling the upper sensor and the lower sensor to be at initial measurement positions; setting parameters of a laser double-measuring head and an X, Y-direction movement mechanism; starting a program, driving a sensor to move along the X direction by a system through a motor driving sliding table, collecting and receiving data of a finite point measured by the sensor, resetting the sensor, performing least square polynomial curve fitting by using the data through a Labview platform to fit a curve, driving the motor to drive the sensor to the vertex in the X direction, and taking the position of the sensor at the moment as an initial position in the Y direction; the control motor drives the sliding table to drive the sensor to move in the Y direction, data of the sensor are collected and received, the sensor is reset, a Y-direction curve is fitted through the Labview platform, the driving motor drives the sensor to the top point of the Y-direction curve, and at the moment, the upper sensor and the lower sensor are both aligned to the center of a sphere, namely, the upper sensor and the lower sensor are aligned.
The invention has the beneficial effects that: (1) the automatic alignment provided by the invention solves the problem of low accuracy caused by a general alignment process; (2) the invention can also be disassembled and assembled after alignment, thus solving the one-off problem of alignment.
Drawings
The invention is further illustrated by the following figures and examples.
Fig. 1 is an overall schematic of the present invention.
Fig. 2 is a schematic view of an automatic slide table in the mechanical system of the present invention.
Fig. 3 is a flow chart of the automatic alignment of the present invention.
Reference number designations in the drawings: 1. the automatic sensor assembling device comprises a side baffle, a mounting plate 2, an upper automatic sliding table 3, an upper sensor clamp 4, an upper sensor 5, a reference object 6, a workpiece table 7, a lower sensor clamp 8, a lower sensor 9, a lower automatic sliding table 10, a support 11 and a motion control card 12.
Detailed Description
A double-measuring-head automatic alignment system based on a laser displacement sensor is characterized in that: the system mainly comprises a mechanical system and a measurement and control system;
the mechanical system comprises a support, a side baffle is arranged at the upper part of the support, an upper mounting plate is arranged at the top of the support, an upper automatic sliding table is mounted on the lower surface of the upper mounting plate, an upper sensor is mounted on the upper automatic sliding table through an upper sensor clamp, a workpiece table arranged on the support is arranged below the upper automatic sliding table, a round hole with the diameter equal to that of a spherical reference object is reserved in the center of the workpiece table, the reference object is placed in the round hole, a lower automatic sliding table mounted on the support is arranged below the workpiece table, and a lower sensor is mounted on the lower automatic sliding table through a lower sensor clamp; the upper sensor and the lower sensor are respectively arranged on the upper side and the lower side of the reference object;
the measurement and control system adopts a motion control card to realize control, and the motion control card controls the upper automatic sliding table and the lower automatic sliding table to move along the X, Y direction through signals given by the upper computer.
The workpiece table is in a form that the workpiece table can be directly drawn out from the bracket.
The sensors move along with the automatic sliding table in the X-Y direction, a curve is fitted by collecting data of finite points, peak points are found, and automatic alignment of the upper sensor and the lower sensor is realized.
Two driving motors for driving the sliding tables to move in the directions x and y which are perpendicular to each other are respectively arranged on the upper automatic sliding table and the lower automatic sliding table.
The working process is as follows:
the first step is as follows: placing a reference object in a workpiece table, and mounting the workpiece table on a bracket;
the second step is that: installing a laser displacement sensor on an automatic sliding table, wherein an upper sensor and a lower sensor are respectively fixed on the upper automatic sliding table and the lower automatic sliding table and are distributed on the upper side and the lower side of a reference object;
the third step: starting a power supply, and enabling the upper sensor and the lower sensor to be at initial measurement positions; setting parameters of a laser double-measuring head and an X, Y-direction movement mechanism; starting a program, driving a sensor to move along the X direction by a system through a motor driving sliding table, collecting and receiving data of a finite point measured by the sensor, resetting the sensor, performing least square polynomial curve fitting by using the data through a Labview platform to fit a curve, driving the motor to drive the sensor to the vertex in the X direction, and taking the position of the sensor at the moment as an initial position in the Y direction; the control motor drives the sliding table to drive the sensor to move in the Y direction, data of the sensor are collected and received, the sensor is reset, a Y-direction curve is fitted through the Labview platform, the driving motor drives the sensor to the top point of the Y-direction curve, and at the moment, the upper sensor and the lower sensor are both aligned to the center of a sphere, namely, the upper sensor and the lower sensor are aligned.