Research On Ultrasonic Three Dimensional Coordinate Measuring System Based On Zigbee

The three-dimensional coordinate measurement has important applications sin modern instrument industry and machinery industry. The existed measuring systems have high cost, poor extensibility or some other problems. To counter these problems, this paper studies a large-size three-dimensional coordinate measuring system which using ultrasonic sensors. To achieve the ultrasonic three-dimensional coordinate measuring systems, this paper made the following studies.Firstly, design the hardware of the system, it contents: a ranging circuit module comprises an ultrasonic transmitter circuit, an ultrasonic receiver circuit, temperature compensation circuit, and power circuit; Zig Bee data transmission module comprising a radio frequency based CC2530 microcontroller nodes and routers design of the terminal node; Build a test platform for testing.Then design the system software. Based on artificial fish swarm algorithm and particle swarm optimization algorithm, this paper has established a three-dimensional coordinate inversion model and simulate the model in MATLAB to verify its feasibility.Simulation results show that in the ultrasonic sensor detection range(0.25-3.5) m, two theoretical simulation model error is less than 0.1mm, after adding the two groups of 6mm random error, the model inversion error were all increased,fish arithmetic error is less than 12 mm, particle swarm optimization is within 10 mm,in three-dimensional coordinates of the problems described in this article inversion model based on PSO is superior to the three-dimensional coordinates of the inversion model fish algorithm.Finally, error compensations is carried out in different ways for the factors which affect the range accuracy and coordinate estimation accuracy, including temperature, the ranging distance, transceiver relative angle and delay time of the hardware. Experimental results show that the estimation coordinate accuracy after error compensation can be controlled within 10 mm.The three-dimensional coordinate measuring system based on ultrasonic sensor developed in this paper is easy to debug and operate, cost lower, can be applied tothe measurement of the profile and volume of the large-size castings and forgings with good prospect.