A NEW TECHNIQUE FOR DETERMINING THE LOCATION OF 3-D OBJECTS USING A TRANSPUTER-CONTROLLED INERTIAL SENSOR

A new technique for determining the location of 3-D objects using an i nertial sensor is presented in this paper. The location information is used to enable an industrial robot to pick up the objects. The sensor consists of a flexible column built-in at one end to the wrist of the robot and a small rigid platform fixed at the other end of the column . Each object to be located is held rigidly with respect to the platfo rm. The static deflections of the column and natural frequencies of vi bration of the dynamic system comprising the object, platform and colu mn are measured. The measured signals are processed using a mathematic al model of the system to determine the location of the object. The on -line computation of the mathematical model is very slow and the compu ted locations are inaccurate owing to the mathematical model not repre senting the actual sensor exactly. This paper describes the implementa tion of a new technique for determining object location. The technique employs the mathematical model off-line to compute the frequencies of vibration for different locations of a given object on the sensor pla tform. A limited number of measurements are taken to correct the compu ted frequency values. The corrected values are stored in a look-up tab le, which is used on-line. The new technique yields more accurate loca tion values and is faster than the previously adopted techniques of lo cation determination. Experimental results obtained using the new tech nique are presented.