Spatial and temporal coarse to fine structuring method of distributed tactile sensors based on changing velocity of the sensation

In order to achieve robots working around humans, whole-body tactile sensation is one of important keys. One problem for achieving such whole-body tactile sensation is data processing for enormous amount of data from distributed sensor elements. Some kinds of sensor data structuring method is necessary for efficient processing of such tactile information. From a view point of whole system architecture of a robot, all of tactile sensor data is not always necessary in the higher level computation. Sensor data for the parts on which given stimuli are changing frequently should be acquired in detail and dense data should be sent to the higher level computation parts. On the other hand, sensor data for the parts on which given stimuli are almost same should be summarized temporally and spatially and sparse data should be sent to the higher level. So far, not many researches are focusing on the structuring method of tactile sensor data. Only a few groups start trials to acquire structured data for whole body tactile information. Basically correlating relationship among tactile sensors are acquired offline in their methods. It is difficult to construct those structured tactile data online for realtime operation of robot´s behavior. Therefore, a new method to conduct online structuring method for tactile sensor data based on the changing velocities of sensor elements is proposed in this paper. Proposed method consists of two stages. At first, tactile sensor data is temporally structured at the level of local processor where A/D conversion is done. There, update frequencies for each sensor elements are automatically changed based on the changing velocities of each sensors. Next, temporally structured tactile sensor data is structured spatially: sensor elements are clustered based on the positional information and update frequencies. Furthermore, experiments using prototype distributed sensor boards are done for verifying proposed method.