This paper establishes an approach to external force estimation for telerobotic control in radioactive environments by the use of an identified manipulator model and pressure sensors, without employing a force/torque sensor. The advantages of -and need forforce feedback have been well-established in the field of telerobotics, where electrical and back-drivable manipulators have traditionally been used. This research proposes a methodology employing hydraulic robots for telerobotics tasks based on a model identification scheme. Comparative results of a force sensor and the proposed approach using a hydraulic telemanipulator are presented under different conditions. This approach not only presents a cost effective solution but also a methodology for force estimation in radioactive environments, where the dose rates limit the use of electronic devices such as sensing equipment.

This paper presents an investigation of a novel development of a multifunctional mobile platform for agriculture applications. This is achieved through a reinvention process of a mechatronic design by spinning off space robotic technologies in terrestrial applications in the AgriRover project. The AgriRover prototype is the first of its kind in exploiting and applying space robotic technologies in precision farming. To optimize energy consumption of the mobile platform, a new dynamic total cost of transport algorithm is proposed and validated. An autonomous navigation system has been developed to enable the AgriRover to operate safely in unstructured farming environments. An object recognition algorithm specific to agriculture-has been investigated and implemented. A novel soil sample collecting mechanism has been designed and prototyped for on-board and in-situ soil quality measurement. The design of the whole system has benefited from the use of a mechatronic design process known as the Tiv model through which a planetary exploration rover is reinvented into the AgriRover for agricultural applications. The Agri-Rover system has gone through three sets of field trials in the UK and some of these results are reported.

No abstract

No abstract

This paper compares Generalised Minimum Variance and Pole-placement techniques for the control of a lightly damped cantilever beam smart structure. Saturation of the control signal can lead to limit cycles in Pole-placement control. Saturation compensation can remove these limit cycles, allowing disturbances of the beam to be rejected, but introduces a low amplitude, higher frequency vibration effect. Control sensitivity functions used to investigate these limit cycles show that certain Pole-placement controllers are sensitive to frequencies in the 50Hz range. The sensitivity of a Generalised minimum variance (GMV) controller is shown to be less than that of the Pole-placement controller. This GMV controller is applied to the vibration control of the smart beam. The controller weightings of the cost function limit excessive control signals. Previous work allows a plant model to be generated that produces results that closely match experimental data. Control results shows that the GMV technique is highly effective in reducing both the decay time and amplitude of vibration for free and forced vibrations respectively.