Linear displacement sensor（直线位移传感器）

Linear displacement sensor（直线位移传感器） Linear displacement sensor(直线位移传感器) The principle and application requirements of linear displacement sensor are introduced briefly Time: 2011-12-22 source: Author: Keywords: linear displacement sensor, use requirements, principles, preface With the development of electronic technology, the requirement of precision control in the process of industrial application has been improved continuously, and the linear displacement sensor (photoelectric sensor) has been developed rapidly. As the linear displacement sensor not only easier to optimize production process, and ensure good quality of production, but also reduce production costs and failure rate. More and more users are more interested in choosing to use analog position control products (pressure sensors). From the potentiometer type sensor to the magnetostrictive principle, and now to the new inductance detection principle, the linear displacement sensor has been continuously developed. By collecting and arranging data, Xiao Bian makes specific introduction to the related knowledge of the linear displacement sensor (the working principle of the pressure sensor). Definition of linear displacement sensor A linear displacement sensor is a device for converting mechanical displacement into a linear or arbitrary function of resistance or voltage output through a potentiometer element. Ordinary linear potentiometer and circular potentiometer can be used as linear displacement and angular displacement sensors respectively. However, in order to achieve the purpose of measuring displacement, a potentiometer must be required to have a definite relationship between the change of displacement and the change of resistance. The movable brush of the linear displacement sensor is connected with the object to be measured, and the displacement of the object causes the change of the resistance of the moving end of the potentiometer. The principle of linear displacement sensor The linear displacement sensor is based on the working principle of the inductance coil. The function of the linear displacement sensor is to convert the linear mechanical displacement into electrical signals. In order to achieve this effect, usually slide set variable resistor in the fixed part of the sensor, to measure the different resistance through the displacement of the slider on the rail. The linear displacement sensor rail connects the steady DC voltage with a small current flowing through the micro ampere. The voltage between the slider and the start is proportional to the length of the slider moving. The use of linear displacement sensors as voltage divider can minimize the accuracy of the total resistance value of the slide rail, because the change of resistance caused by the temperature changes will not affect the measurement results. The measuring principle of the new linear displacement sensor is based on the RLC coupling circuit, and it is an innovative technology of inductance principle. Unlike the detection principle of potentiometer or magnetostrictive sensors, this method of measurement has considerable advantages. The linear displacement sensor incorporates a signal emitter and receiver coil system that is printed precisely on the circuit board in the form of a printed coil. The transmitting signal coil is activated by a high frequency AC magnetic field and is induced with the position block (resonator) to generate a RLC induction circuit. Therefore, the resonator and the receiving coil are inductively coupled. In the position where the cloth receives the signal coil, the change in the voltage is caused by the induction of the resonator and the coil. These voltages are the measuring signals of the sensors. To make the measurement more flexible and fast, the sensor contains a rough and precise measuring coil system. The former is responsible for rough positioning of the resonator, while the latter is responsible for accurate positioning. The two pronged method ensures its accurate measurement. The detection principle of the utility model not only ensures the accuracy of the sensor, but also can make the sensor work in a non-contact manner, within the allowable range, even if the position block offset or jitter, will not produce any deviation of the sensor output. Application fields of linear displacement sensors Application fields of general linear displacement sensors 1, KTC, KTM, LS rod structure is a general structure, with optional pull ball universal head or fish eye universal head, can reduce the installation of non neutral and adverse effects; 2, KPC and KPM are fixed at both ends, with a twist motion type, suitable for swinging, the sensor body can not be fixed in the measurement system, the sensor will move with the measurement of movement; 3, KTF, KFM slider type to adapt to the minimum installation length size of the application, combined with long arm, can eliminate the installation of non alignment of the adverse effects; The 4 and KTR type is a miniature self recovery compound rod structure, which needs no traction installation; The 5 and KPF type flange surface fixing structure can detect the internal displacement of the cavity more Classification of general linear displacement sensors (1) pull rod linear displacement sensor; Universal pull rod conductive plastic film series, effective travel 75mm ~ 1250mm, both ends have 4mm buffer stroke, accuracy 0.05% ~ 0.04%FS. The surface of the shell is anodized to prevent corrosion. The built-in conductive plastic measuring unit has no temperature drift and long service life. It has automatic electrical grounding function. The sealing grade is IP67, and the DIN430650 standard plug and socket can be applied to most general occasions. The tie rod head has the 0.5mm automatic centering function, Allow extreme speed of movement of 10m/s (2) sliding linear displacement sensor General slide block conductive plastic film series, effective travel 75mm ~ 3000mm, both ends have 4mm buffer stroke, accuracy 0.05% ~ 0.02%FS. The surface of the shell is anodized to prevent corrosion. The built-in conductive plastic measuring unit has no temperature drift and long service life. It has automatic electrical grounding function. Sealed to IP54 (when installed down to IP57), DIN430650 standard plugs and sockets, can be applied in most common situations, especially the length restrictions of the more difficult situations; rod with a 10mm ball head with automatic correction function, speed limit allowed for 10m/s. Requirements for the use of linear displacement sensors 1, the supply voltage to be stable Industrial power requirements require a stability of + 0.1%, such as a reference voltage 10V, allowing fluctuations of + 0.01V, otherwise, the displayed trap fluctuations. If the fluctuation range of the display does not exceed the fluctuation range of the fluctuation voltage, the displacement sensor electronic ruler is normal. 2. prevent static interference Electrostatic interference and FM interference are very easy to cause the electronic ruler to display digital beats. The strong line of the equipment is separated from the signal line of the electronic ruler. The electronic ruler should use the mandatory grounding bracket, and the electronic scale shell (measurable end cap between the screw and the bracket resistance should be less than 1 ohm resistance) good grounding, signal line shielding wire, and one end in electrical box should be shielding grounding line. When static electricity is disturbed, the voltage measurement of the general multimeter is very normal, but it shows the digital jitter. Verify that it is not static interference, and use a power cord to connect the cover screw of the electronic ruler with a certain metal on the machine. As long as a short connection, the static interference is eliminated immediately. But the high frequency interference is difficult to eliminate by the above method, moreover, the robot hand, the frequency changer appears frequently the high frequency disturbance, may use stops the mechanical hand or the frequency conversion Saver method verification. 3, you can not pick the wrong three lines of electronic ruler "1" and "3" line is the power line, "2" is the output line, in addition to the power line ("1", "3" line) can be changed, the "2" line can only be output line. Once the line is connected to the wrong, there will be a large linear error, the emergence of control is very difficult, poor control accuracy, easy to display jitter and so on. 4 、 the power supply should have enough capacity If the power supply capacity is too small, it is easy to happen as follows: die movement will lead to the display of electronic ruler to show jitter, or the movement of adhesive will lead to the display of the analog electronic ruler fluctuations. Especially, the electromagnetic valve driving power supply is easy to occur when the electronic ruler and the power supply are together, and the voltage fluctuation of the multimeter can be used to measure the voltage fluctuation in a severe condition. If the static interference, high frequency interference and neutral condition can not be solved, the power of the power supply is also suspected to be too small. 5, installation is better for neutral Angle allows + 12 degrees error, parallelism allows + 0.5mm, if the angle error and parallelism error is too large, will lead to digital display jitter. In this case, we must adjust the angle and line of action. 6. Avoid short circuits Linear displacement sensor of electronic scale in the process of work, regularly at a certain point display data beat or not display data, it will check the cable insulation is damaged and metal shell and machine regular contact caused by short circuit to ground. 7, avoid aging For a long time using electronic scale and seal aging, there may be a lot of impurities, and the oil and water mixture, affect the contact resistance of brush, LED display digital beat, can be regarded as the early damage of the linear displacement sensor of the electronic scale itself. summary The application and development of linear displacement sensor make sensor family move to a new stage, and also have more competitive power in electronic components. This paper briefly introduces the definition, principle and application fields of the linear displacement sensor. And the classification and application requirements of the linear displacement sensor are introduced in detail.