Research On Position Detection Novel Method Based On Parasitic Time-grating For Inductive Motor

Now commonly used servo motors with high precision and performance arebased on the accurate and reliable of the value of rotor position and speed. Atpresent, in mostly regulation servo systems, the mostly method is to install the opticalencoders or electromagnetic resolvers on the rotor shaft. But the external locationsensors have many drawbacks in service, so look for ways to design a location sensorwithout destructing their structure and having high accuracy position which becomethe best solution for the study of rotor position detecting of servo motor.Time grating is new principle, high precision and high resolution sensor and hasbeen widely accepted in precision measure field, and its structure has ‘twin’ relationswith induction motor, so time grating can be transplanted into the original structure ofinduction servo motors to get its position and velocity information. This newinduction servo motor not only can provide power but also enable to realize theprecision position detection. The parasitic time-grating sensor-motor offer manyadvantages over other external location sensors in the performance, costs, structureand so forth.The key point of the paper is summery and evaluation of field study status, onwhich discussion how time grating can be transplanted into the original structure ofinduction servo motors to get its position and velocity information. These main jobscompleted are included:1. This article focuses on the core of the relationship between Time grating andinduction motor in their structures and work theory for realizing the "seamless joint"of them.2. Carrier wave injecting the excitation signal of time grating in induction motorby a stereoscopic triangular iron core combined transformer. There will have twoelectromagnetic fields in air gap, and the interaction of electromagnetic fields withrotor winding creates weak electric signals which contained the location informationof the rotor.3. Sending the inductive signals to the time grating controller by a contactlesselectromagnetic coupling transformer or a wireless analog transmitter, and thengetting the signal which contained the location information of the rotor by signalprocessing. 4. To measure the location information of the rotor through using the comparisonphase method, so it can realizes the servo motor control.