A Free-Liquid-Piston Engine Compressor for Compact Robot Power

2003 IEEE International Conference on Robotics and Automation (Cat. No.03CH37422)

This paper describes the design of a liquid-propellantpowered hot-gas actuator appropriate for human-scale power-autonomous robots. A prototype of the actuation system is described, and closed-loop tracking data is shown that demonstrates good motion control. Experiments to characterize the energetic performance of the actuation system indicate that the proposed system with a diluted propellant offers an energetic figure of merit five times greater than a battery-powered DC motor actuated system. Projections based on these experiments indicate that the same system powered by undiluted propellant would offer an energetic figure of merit an order of magnitude greater than battery-powered DC motor actuated systems.

The pneumatically operated vehicle is used to save the non-renewable sources of energy and stop the environmental pollution, which is harmful for human beings. Now a days battery operated vehicles used in all manufacturing industries has disadvantages like high weight, takes more time to charge the battery, critical connection of switches and relays. It requires more maintenance. These problems are solves in pneumatically operated vehicle which has low weight, easy circuits, takes less time for refuelling and requires less maintenance. The Compressed Air Powered Vehicle works on the principle of the compressed Air Technology (CAT). This energy can be utilized for useful purposes. When this compressed air expands, the energy is released to do work. By using the above Concept we are designed a prototype model of pneumatically operated vehicle. In this system a double acting pneumatic cylinder is operated as a slider crank mechanism which converts the linear reciprocation of the cylind...

IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004, 2004

This paper introduces a new control method for pneumatic actuators, called "Proportional Position and Stiffness (PPS)" controller. The PPS method provides both position and stiffness control for a robot joint driven by a pneumatic cylinder with four ON-OFF valves. In addition, the proposed control system consumes much less compressed air than comparable strategies. These features make the PPS method highly suitable to applications on mobile robots.

Dynamic Systems and Control, 2002

This paper describes the design of a liquid-propellant-powered hot-gas actuator appropriate for human-scale power-autonomous robots. The motivation for this work is the development of a lightweight actuation system with system energy and power densities significantly greater than a DC motor and battery combination. The proposed design of a liquid-fueled actuator is presented, followed by a thermodynamic model of the system. A single-degree of freedom manipulator prototype is presented, and closed-loop tracking control of the liquid-fueled actuator is demonstrated. The measured energy density of the system is presented, and this experimental result is followed by a discussion that correlates the theoretical energy density predicted by the model with the measured energy density of the prototype. The analysis presented in the discussion section indicates that heat flow in the uninsulated experimental prototype constitutes a significant loss of energy, and that if properly insulated, th...

Soft robotics, 2014

Many pneumatic energy sources are available for use in autonomous and wearable soft robotics, but it is often not obvious which options are most desirable or even how to compare them. To address this, we compare pneumatic energy sources and review their relative merits. We evaluate commercially available battery-based microcompressors (singly, in parallel, and in series) and cylinders of high-pressure fluid (air and carbon dioxide). We identify energy density (joules/gram) and flow capacity (liters/gram) normalized by the mass of the entire fuel system (versus net fuel mass) as key metrics for soft robotic power systems. We also review research projects using combustion (methane and butane) and monopropellant decomposition (hydrogen peroxide), citing theoretical and experimental values. Comparison factors including heat, effective energy density, and working pressure/flow rate are covered. We conclude by comparing the key metrics behind each technology. Battery-powered microcompressors provide relatively high capacity, but maximum pressure and flow rates are low. Cylinders of compressed fluid provide high pressures and flow rates, but their limited capacity leads to short operating times. While methane and butane possess the highest net fuel energy densities, they typically react at speeds and pressures too high for many soft robots and require extensive system-level development. Hydrogen peroxide decomposition requires not only few additional parts (no pump or ignition system) but also considerable system-level development. We anticipate that this study will provide a framework for configuring fuel systems in soft robotics.

International Journal of Engineering Research and

Present scenario of the world describes, the crisis of fuel and pollution problem, along with it, conventional sources are about to deplete in near years. So, the search on alternative fuels is on progress and in demand too. Today there are several solutions to meet demand for better economy in fuel and one of them is the concept of pneumatic-hybrids. The project focuses on a hybrid-vehicle driven by air as alternate source to fuel and a battery driven too, to reduce the dependency on conventional sources. In this, compressed air is stored in storage tank/ compressor& pneumatic motor is used for conversion of pressure to mechanical energy. This pneumatic-hybrid vehicle is not only eco-friendly, pollution free but also very economical. An Experimental Analysis to develop a Hybrid Pneumatic Vehicle that works on compressed air. The vehicle is powered by a compressed-air engine and can be later switched to batteries. The vehicle uses a non-renewable and pollution free fuel. A Pneumatic Vehicle is a pneumatic actuator that creates useful work by expanding compressed air. When this compressed air expands, the energy is released to do work. So this energy in compressed air can also be utilized to displace a piston.

The paper presents the possibility of use of the pneumatic piston engine with two-stroke cycle of the work as an alternative drive source or additional power for the battery regeneration in the electric vehicles. The energy for the engine work is taken from the energy of the air stored at high pressure (about 30 MPa) in the bottle. The pressure in the bottle is reduced to smaller value and the air is injected to the cylinder at short time when piston is in TDC position by the pneumatic injector. The engine has not the transfer ports and its torque depends on the air pressure, injection timing and engine speed. The two-stroke cycle work enables better efficiency and specific air consumption than that with a four-stroke cycle of the work. The pneumatic engine of small dimensions, however with high power fulfil the regulations of the environmental protection with zero emission. The paper presents the mathematical model of the engine based on thermodynamic processes (mass and energy bal...

International Journal of New Technology and Research, 2019

In the present scenario of world, the engineers having the challenges to find the different ways drive efficient by using the alternative energy sources which are the eco-friendly to environment. The compressed air is used as a source for various operations in the industry and also having the ennivormental friendly. So, the engineers are focused on the compressed air as non-polluting fuel for the vehicles which is termed as pneumatic cars. This paper describes the brief introduction to latest development of pneumatic cars, the efficiency and properties of the compressed air with respect to enthalpy, internal energy, density of the compressed air. The working of the pneumatic car, with the use of the pneumatic actuators that creates useful work by expanding the compressed air, electronic component with simple mechanism. Hence, the pneumatic cars are affordable, safe and future of the automobile industry.

Energies, 2021

During pneumatic control system design, the critical value for choosing the appropriate pneumatic actuator is the weight of the workpiece. In the case of flexible production systems, which are the core part of the Industry 4.0 (I4.0) concept, the weight of the workpieces is often variable, since the crucial feature of this kind of production is its ability to deal with variable parts. Therefore, in order to deal with the variable weight of parts, a pneumatic actuator is chosen according to the heaviest part. However, according to another I4.0 principle, energy efficient operation of machines, the previous criteria for choosing a pneumatic actuator is energy efficient only when handling the heaviest part. In all other cases, operation of the pneumatic actuator is suboptimal in terms of energy efficiency. Aiming to solve this problem, this paper considers the possibility of using a new pressure regulator instead of traditional manually adjusted pressure regulators. This regulator prov...

Journal of dynamic systems, …, 2006

This paper proposes a control approach that provides significant energy savings for the control of pneumatic servo systems. The control methodology is formulated by decoupling the standard four-way spool valve used for pneumatic servo control into two three-way valves, then using the resulting two control degrees of freedom to simultaneously satisfy a performance constraint based on the sliding mode sliding condition, and an energy-saving dynamic constraint that minimizes cylinder pressures. The control formulation is presented, followed by experimental results that indicate significant energy savings with essentially no compromise in tracking performance relative to a standard sliding mode approach. Relative to a standard four-way spool valve controlled pneumatic servo actuator under sliding mode control, the experimental results indicate energy savings of 27 to 45%, depending on the desired tracking frequency.