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This paper proposes a method to verify the performance of a redundant 4 degree of freedoms (DOF) hydraulic manipulator when Virtual Spring-damper (VSD) algorithm is applied. It is combined with a control based on the VSD algorithm proposed by Ari-moto et al. To verify the applicability of VSD algorithm to the hydraulic robot manipulator of redundancy 4-DOF, we conducted an experiment to tracking repetitive circle motions of 0.2 m radius to the Y-Z plane in 3.5 seconds. To check the control performance to all directions, the experiment was conducted to the repetitive circle motions which are sloped to 30 ° to the X axis. The effectiveness of the proposed control scheme is demonstrated in experimentation with the 4-DOF manipulator.

This paper deals with estimating the attitude of a walking quadruped robot in the presence of engine noise. Contrary to wheeled robots, legged robots are inherently supposed to work in uneven environment. Therefore estimating the attitude of walking legged robot becomes the utmost important factor in designing such machines in order to control them. We have used IMU as the prime sensor for stabilized attitude estimation. In fact accelerometer is used for roll/pitch observations in stationary/quasi-stationary state. But this data is not suitable unless pre-processing. This involves the pre-filtering and error factor determination for raw IMU data. Engine vibration effects are removed by low-pass filter and error-factor are calculated by least square fit to raw IMU data. Finally results of applying these simple techniques show the stability of attitude estimation on quadruped walking robot in real experiment.

P-SURO is a prototype autonomous underwater vehicle (AUV), which is under development as a test-bed for developing underwater technologies such as underwater vision, underwater navigation, and guidance. This vehicle is a hovering type with four thrusters mounted to steer its 6DOF underwater motion, a color camera is mounted at the vehicle's nose for underwater vision, and an AHRS combined with one depth sensor and three range sonars construct an inertial navigation system. In this paper, we report the details of constructions of the vehicle system, and its three core modules - vision module, navigation module, and control module.

Reference trajectory formation is a starting point and used as a target value of control. It is a set of points regarded as the target in every interrupt routine of control procedure and, therefore, called motion profile for a moving system under the tracking. Instead of usual trajectories which are the continuous functions of time, a practical discrete trajectory formation method which has a polynomial nature but more application to the real robot systems is compared to the continuous time version which is the analytical solution presented by different authors in the same year 2004 at different places. The effectiveness of this practical method, ASPOT, is verified through the experiments using a linear motor system. Especially, the most important benefit with respect to the CPU time is shown through the implementation of the algorithms on a DSP. ASPOT takes just 5~6 % of the time for common polynomial case does as well as it producing all derivative states simultaneously