Holonomic omnidirectional mobile robots are useful because of their high level of mobility in narrow or crowded areas, and omnidirectional robots equipped with normal tires are desired for their ability to surmount difference in level as well as their vibration suppression and ride comfort. A casterdrive mechanism using normal tires has been developed to realize a holonomic omnidiredctional robot, but some problems has remain. Here we describe effective systems to control the caster-drive wheels of an omnidirectional mobile robot. We propose a Differential-Drive Steering System (DDSS) using differential gearing to improve the operation ratio of motors. The DDSS generates driving and steering torque effectively from two motors. Simulation and experimental results show that the proposed system is effective for holonomic omnidirectional mobile robots.

In today’s situation with high needs for care, a transfer work, among various assisting works, produces particularly large physical burden. The burden could result in not only diseases including waist pain but also resignation of care workers. A nursing lift used to reduce the burden lifts up a care receiver by using a wire or mechanical structure, causing sway. The sway not only makes the care receiver uncomfortable but also causes a risk of unintentional collision. To prevent such a situation, carers need to assist care receivers by holding them while simultaneously operating equipment and paying attention to the care receivers, which is not preferable from a viewpoint of work safety. In this study, we experimentally analyzed and discussed sway of a person when he/she is lifted up. On the basis of an analysis result, we propose an automatic control method of dynamical speed change for safe lifting works, which is applicable to ordinary nursing lifts.

In this paper, we present design and analysis of a novel nursing lift and wheelchair which can run towards omnidirectional on the ground. The proposed assistive robot provides a power assist function for transfer aid system with hoisting, and also an omnidirectional motion function using DDSS (Differential Drive Steering System). By transforming the length of Boom, Shaft, and Leg Parts, novel power assist robot can easily transfer the person from wheelchair to bed, and vice versa, and furthermore can carry the person as a wheelchair. To show the usefulness of the proposed robot, several experiments with a series of nursing operation have been done in the present research.

This paper presents an advanced operational support system for an intelligent crane. In the present paper, a joystick-type control which can realize the suppression of load sway and obstacle avoidance is proposed. An environment recognition system, where the surrounding environment is recognized by a laser scanning sensor on real-time, was built into the system. The joystick has a haptic control system that responds to the risk of the operation. It transmits a reaction force to the operator based on data about the distance between the crane and obstacles in the environment map generated by the environment recognition system. Furthermore, the load sway is suppressed by a notch filter. The effectiveness of the proposed crane system was shown through experiments.

The authors have been developing a mobile robot to assist doctors in hospitals in managing medical tools and patient electronic medical records. The robot tracks behind a mobile medical worker while maintaining a constant distance from the worker. However, it was difficult to detect objects in the sensor’s invisible region, called occlusion. In this study, we propose a sensor fusion method to estimate the position of a robot tracking target indirectly by an inertial measurement unit (IMU) in addition to the direct measurement by an laser range finder (LRF) and develop a human tracking system to avoid occlusion by a mobile robot. Based on this, we perform detailed experimental verification of tracking a specified person to verify the validity of the proposed method.