The Research On The Grating-shape Capacitive Coder And Its Application

Capacitive sensor is always used as measure device with high precision, but its measure scale is very small. The grating-shape capacitive coder widens its measure scale; meanwhile it also has many advantages for instance simple structure, low power and high ratio between quality and cost etc. However because of original faults, the grating-shape capacitive coder is restricted in the display ruler; in the other places, there is almost no product related.In the paper firstly I introduce the mechanical structure, measure theory and inner chip of the grating-shape capacitive coder. Aiming at the fault of the low work reliability, we improve the mechanical structure and the electronic circuit to enhance its work reliability. Nowadays multi-point communication is a development field; in the coder's design, we consider the master-slave communication function to make the grating-shape capacitive coder fit for the advanced manufacture better.The concrete description of the grating-shape capacitive coder's precision is little in the reference materials. I analyze the factors maybe influencing the coder's precision; then use the photoelectric coder linking with the grating-shape capacitive coder in the same axis to test the error between the photoelectric coder and the grating-shape capacitive coder. According to different rotatable velocity, location, communication velocity, I draw the error curves to give a concrete description of grating-shape capacitive coder dynamic and static precision.Now the grating-shape capacitive products need the battery support. When there is no periphery power supply for a long time, the battery's capacity becomes smaller and smaller; it will bring out many indefinite factors to the grating-shape capacitive coder; while it is serious enough, the coder is even out of work. So I do the experiment to confirm the coder's data unique without the periphery power supply according to the measure theory; then with the new design idea, I design the mechanical structure to realize the grating-shape capacitive coder without battery.Finally I describe the practical application with the grating-shape capacitive...