Classification and characteristics of the detectio

2022-08-14
  • Detail

Classification and characteristics of measuring machine detection system

detection system is a system composed of measuring head and its accessories. The measuring head is a device that sends signals when the measuring machine detects. It can output switching signals and proportional signals proportional to the deflection angle of the probe. It is a key component of coordinate measuring machine. The accuracy of the measuring head largely determines the measurement repeatability and accuracy of the measuring machine; Different parts need to be measured with probes with different functions

1. Classification of probe

1.1 Trigger probe and scanning probe:

trigger probe: also known as switch probe, the main task of the probe is to detect parts and send a locking signal to lock the three-dimensional coordinate values of the measured surface coordinate points in real time

the trigger probe generally sends a jumping square wave electrical signal, and uses the leading edge jump of the electrical signal as the latch signal. Because the leading edge signal is very steep, which is generally at the microsecond level, the real-time nature of the latch coordinate value is guaranteed

scanning probe: also known as proportional probe or analog probe, this kind of probe can not only be used as a trigger probe, but also can output a signal proportional to the deflection of the probe (analog voltage or digital signal), and the computer can read the probe deflection and the three-dimensional coordinate signal of the measuring machine at the same time (when it is used as a trigger probe, the three-dimensional coordinate value of the coordinate point on the detection surface is locked), To ensure that the three-dimensional coordinates of the detected point can be obtained in real time. Since there is no mechanical reciprocating motion of the measuring machine when taking points, the sampling rate will be greatly improved in the future. When the scanning probe is used for discrete point measurement, because the three-dimensional motion of the probe can determine the normal direction of the surface where the point is located, it is more suitable for surface measurement

1.2. The length difference between the two largest diagonals o1o1 and o2o2 of the contact probe and the non-contact probe is not more than 0.3mm:

contact probe: a detection system that needs to make physical contact with the surface to be measured

non contact probe: a detection system that does not need physical contact with the surface to be measured; For example, optical detection system and laser scanning detection system

2. Main components and characteristics of contact detection system

it is not always easy to choose a suitable detection system for the measurement task. It needs to start from determining the type, measurement efficiency and measurement range of the measured workpiece, which can detect the markers of major diseases such as cancer through the fluorescence changes caused by the contact of functional nano materials with cancer cells. The following is a summary of various detection systems and their main application fields, in order to select the most suitable detection system and sensor for your measurement needs

2.1. Indexing measuring base

manual rotating measuring base of integrated measuring head

features: basic, economical and practical integrated measuring head and measuring base system, which can manually locate the orientation of the built-in measuring head, so as to complete the measurement of all features of the workpiece in space

application: detection of three-dimensional box parts

manual indexing measuring base of integrated measuring head

features: the integrated measuring head and measuring base system with two degrees of freedom allows the built-in measuring head to be manually positioned in space with the set repeatable indexing, which improves the flexibility of manual and mobile measuring machines

application: detection of three-dimensional box parts

automatic indexable measuring seat

features: the measuring seat with two degrees of freedom can automatically position the measuring head with good repeatability in the space, and can automatically replace the measuring sensor. After rotation, there is no need to recalibrate the measuring head, so the most suitable angle measurement can be selected for the surface of the workpiece

application: inspection of multi surface box parts

2.2 Probe

point to point trigger probe

feature: the trigger electronic probe with a wide range of 20mm between the upper and lower pressing plates can complete rapid and repetitive measurement tasks by using the lifting and moving beam. It has long service life, accuracy, ease of use, relatively low cost and small measurement space limitations

application: suitable for the measurement of three-dimensional box parts

indexable replacement scanning probe

features: high precision and fast scanning probe, through obtaining a large number of data points, complete the reliable measurement of box parts and contour surfaces. It can be installed on the indexing measuring base and can be interchanged with other measuring heads

application: it is used for the measurement of geometric elements, complex shapes and contours, and provides a complete description of geometric features such as size, position and shape

fixed scanning probe

features: the scanning measuring seat with extremely high precision can send continuous data information to the measuring machine. It is installed on the z-axis of the measuring machine, and can be configured with a long extension rod to complete the measurement of deeper characteristic elements

application: with high detection accuracy, it is widely used to detect shape errors, complex geometric shapes and contour shapes, including size, position and shape

non contact optical probe

features: use to judge the feature type (gray value of contour) generated by shadow and Reflection on photoelectric devices, manually align or automatically send a latch signal, and latch the two-dimensional coordinates perpendicular to the optical axis

application: complete the amplification measurement of small dimensional features, especially when there are small measurement features on large workpieces

non contact laser scanning probe

features: the non-contact laser scanning probe uses the triangulation method. The two-dimensional coordinates perpendicular to the direction of the probe are given by the coordinate system of the measuring machine, and the dimension of the optical axis is given by the position of the detection axis of the measuring machine based on the triangle principle. It can obtain a large number of data point clouds on the workpiece surface in a short time

application: it can not only complete digital measurement and realize the application of reverse engineering, but also complete CAD comparison measurement and analysis of complex geometric shapes and elements

2.3. Attachment

replacement rack

feature: quickly and repeatedly replace the probe/extension rod/probe combination on the measuring base of the measuring machine

application: fully automated detection of different workpieces under the same measurement system

extension rod and probe

features: suitable for most accessories required for testing

application: ensure that the probe can measure all characteristic elements of the workpiece without restriction, and has the ability to measure deep position features. (end)

Copyright © 2011 JIN SHI