Functionalization of Tactile Sensation for Robot Based on Haptograph and Modal Decomposition

In the real world, robots should be able to recognize the environment in order to be of help to humans. Video cameras and laser rangers cannot record tactile information of road surfaces. This paper proposes a method that involves the use of haptograph and modal decomposition for the haptic recognition of road environments. The haptograph presents a graphic view of the tactile information obtained by a disturbance observer. It is possible to classify road conditions intuitively. The robot has two direct-drive motors that are controlled by a velocity control system using a second-order quarry matrix Q2. Fig. 1 shows a block diagram of the velocity control system. The realworld joint space is transformed to virtual-world modal space by Q2. On the other hand, the transformation from the virtual-world modal space to the real-world joint space is realized using a inverse quarry matrix Q−1 2 . By these transformations, the velocity control system of the mobile robot using the quarry matrix independently realizes the translational mode velocity and rotational mode velocity. The disturbance observer is used to estimate the right and left disturbance torques τ̂dis R , τ̂ dis L from environment without force sensors. These torque values are transformed into modal space by using Q2: [ Fdis T dis ]