柴田 昌明

The paper descries a novel method to extract line segments and circular arcs from the image taken by CCD camera for object recognition. Model based matching is one of the widely used techniques of the object recognition in computer vision, and the position and orientation of the objects are decided with referring the extracted line segments and circular arcs. For the precise and stable decisions of the position and orientation, the accurate extractions of characters are required. These characters are. fast and accurately extracted in the proposed method, while its validity is confirmed in some experiments.

This paper describes a nobel method of force/torque sensorless control for a single link flexible arm. The flexible arm includes multiple oscillation modes and its dynamical behavior is generally described as multiple mass spring system. In such a system, it is necessary to suppress the vibrations induced by the multiple oscillation modes. To address the above issue, first, this paper shows that the system stability increases by a feedback of reaction torque. In the proposed approach, the reaction torque is identified by using disturbance observer. Furthermore it is possible to estimate the position where the flexible link arm contacts with target environment. These features make it easy to realize the force/torque sensorless control. Second, the analytical comparison between the sensor-based approach and sensorless approach is described. These analyses show that sensorless approach is effective for a realization of stable force control in the flexible link arm system. The validity of the proposed method is confirmed in several experimental results.

Motion control is now recognized as a key technology in mechatronics. The robustness of motion control will be represented as a function of stiffness and a basis for practical realization, Target of motion is parameterized by control stiffness which could be variable according to the task reference, However, the system robustness of motion always requires very high stiffness in the controller. The paper shows that control of acceleration realizes specified motion simultaneously with keeping the robustness very high, The acceleration is a bridge to connect such robustness and variable stiffness, For practical applications, a technique to estimate disturbance is introduced to make motion controller to be an acceleration controller. Motion control of flexible structure and identification of mechanical parameters are also described.

This paper proposes a unified control strategy of position and force. Our technique is based on impedance control with fuzzy logic and realizes the smooth shift from position control to force control and vice versa. At first, a robust impedance controller based on disturbance observer is shown, and the method to unify the position and the force control through one controller is described. Next, the algorithm to estimate the dynamic characteristics of the environment is shown, and a force tracking control using the estimated parameters is proposed. Finally, the unified control algorithm of position and force based on fuzzy logic is established. The validity of our method is confirmed by several experimental results.