We describe three bipedal robots that are designed and controlled based on principles learned from the gaits of passive dynamic walking robots. This paper explains the common control structure and design procedure used to determine the mechanical and control parameters of each robot. We present this work in the context of three robots: Denise, the Delft pneumatic biped, R1, a highly backdrivable electric biped, and R2, a hydraulic biped. This work illustrates the application of passive dynamic principles to powered systems with significant control authority.

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Energetic autonomy of a hydraulic-based mobile field robot requires a power source capable of both electrical and hydraulic power generation. While the hydraulic power is used for locomotion, the electric power is used for the computer, sensors and other peripherals. An internal combustion engine was used as the prime mover due to the high energy density of gasoline. The primary specification for this hybrid Hydraulic-Electric Power Unit (HEPU) is that it must output constant pres-sure hydraulic power and constant voltage electric power. An on-board computer uses a pressure sensor and a speed sensor to regulate the pressure and voltage by modulating a hydraulic solenoid valve and an engine throttle. The speed regulation also results in a system noise with predictable frequency band which allows for optimal muffler design. A novel characteristic of this power source is its cooling system in which hydraulic fluid is used to cool the engine cylinders.

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In this paper we present a method to control a one-legged lower extre-mities orthosis by analyzing the current trajectory performed with the healthy leg and feeding a proper- if necessary phase-shifted — trajectory to the disabled leg encased in the orthosis. For this, a fast and simple modified version of the cross correlation is used. The algorithm works on multiple reference curves by minimizing the error between the reference and the current data by adaptively walking forward through the reference of the healthy leg and reporting back the reference values for the disabled leg. The proposed method will be part of a control system for an exoskeleton robot that should aid the wearer in everyday-life situations like walking, standing up and sitting down. The performance of the presented method was investigated on the leg movement in sagittal plane without contact to unknown obstacles.

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In this paper we present a method to calculate the intended motion of joints in the human body by analysing EMG signals. Those signals are emitted by the muscles attached to the adjoining bones during their activation. With the resulting intended motion a leg orthosis will later be controled in real-time to support disabled people while walking or climbing stairs and help patients suffering from the effects of a stroke in their rehabilitation efforts. To allow a variety of different motions, a human body model with physical properties is developed and synchronized with data recorded from the pose sensors. Computing the intended motion is performed by converting calibrated EMG signals to muscle forces which animate the model. The algorithm was evaluated with experiments showing the calculated intended motion while climbing one step of a stair. The algorithm and the experimental results are both shown.

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This paper describes some micro turbine aspects from the standpoint of potential users. First, some of the pros and the cons of small gas turbines compared to other competing technologies are given. The discussed aspects are mainly focussed on technical advantages and disadvan-tages as it is hard to predict how fast and to what extent the different technologies (including that of mini gas turbines) will mature. Even though the final applications will obviously strongly depend upon the economical benefits that the technology would offer, an economical comparison is not made here. Therefore the comparison made throughout this contribution remains relatively general. Once the pros and the cons are discussed, some potential applications are described. The possible applications are divided into two different categories: power generation for portable devices and vehicle propulsion. For each class of applications some examples are given. Finally, then, some conclusions are drawn.

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