Abstract: A method of controlling a vehicle hydraulic drive system of the type including a plurality of fluid pressure actuated wheel motors (13,15) connected in a parallel circuit with a source (17) of pressure. A flow restrictor valve (65) is disposed in a downstream conduit (27) of each of the wheel motors (13,15). The method involves determining the theoretical fluid flow for each motor, the actual fluid flow through each motor, and generating an error signal (107) which is then used to bias the restrictor valve (65) toward a flow restriction position. The disclosed method can be used to achieve steering at greater than kinematic, by scrubbing the inside front wheel, or can be used to prevent wheel slip of propulsion wheels, or can be used to prevent scrubbing of a wheel during hydrostatic braking, or can even be used to achieve vehicle steering.

Abstract: A configurable I/O arrangement for a controller has a number of internal and external input/output terminals, each of which are field selected as either an input or an output terminal. Logic functions of the controller are configured for a number of output terminals using up to 32 internal logical states and the states of 32 external physical I/O points. The update timing for each logic circuit is selectable to be synchronized in several different ways: synchronous with an internal event within the controller, synchronous with an event external to the controller, and asynchronous. The I/O arrangement includes a combination of a synchronous latchable input state array, user configurable means for logically combining the output signals of the reading circuits, and means for actuating external devices as a function of the logical combinations of the output signals of the reading circuits.

Abstract: An inflatable external fuel tank is disclosed for carrying fuel under an aircraft wing, the tank having a predetermined displacement when full and being collapsible to a lesser displacement when empty. The tank skin is comprised of a flexible thermoplastic material. A keel structure is located inside the tank and defines the diameter and longitudinal length of the tank.

Abstract: Containment vessels including external aircraft fuel tanks having an internal plastic liner compatible with the substance to be stored in the vessel or tank. The plastic liner is manufactured from a cold formable thermoplastic polyurethane elastomer material that can be formed to the desired material configuration of the vessel. In a fuel tank the annular structural elements of the tank can be smoothly enveloped to provide a seamless, fluid tight liner having superior physical and chemical properties.A method of cold forming the plastic liner from a tubular element to achieve a seamless liner for a containment vessel is disclosed.