Abstract: A method of monitoring or assessing the motion of the limbs of a body when performing repetitive cyclic activity uses inertial measurement units secured to each of the limbs to be monitored. The operation of all of the IMUs is synchronized by way of a pulse from a computer. On performing the repetitive cyclic activity such as walking, running, trotting or galloping, the outputs of the IMUs are assembled and analyzed in realtime, to determine the relative phase of the limb movements, from which an assessment of the gait may be made.

Abstract: A method of monitoring or assessing the motion of the limbs of a body when performing repetitive cyclic activity uses inertial measurement units secured to each of the limbs to be monitored. The operation of all of the IMUs is synchronised by way of a pulse from a computer. On performing the repetitive cyclic activity such as walking, running, trotting or galloping, the outputs of the IMUs are assembled and analysed in realtime, to determine the relative phase of the limb movements, from which an assessment of the gait may be made.

Abstract: A solid state angular rate sensor is fabricated by preparation of a disc-shaped base structure (10) having first and second outer layers of a piezo-electric ceramic material, built up from a number of layers of a ceramic sheet or film that is capable of being tape-cast. The layers are then sintered and an inner layer of metallic material is provided between the outer layers, to complete a piezo-electric base structure having an inner electrode (15) between the sintered outer layers. Arrays of electrode structures are provided on the outer layers of the base structure (10), the electrodes radiating from the central region 14 of the base structure (10) and being equi-spaced around the outer edge of the disc (19).

Abstract: A micro-electro-mechanical systems (MEMS) accelerometer comprises a wafer micro-fabricated to provide a frame (10) defining an opening within which is disposed a sensing mass (14). A pair of aligned pivot beams (15) connect the mass to the frame (10) so that the axis of pivoting is displaced from the centre of gravity of the mass. At least one sensing beam (16) connects the mass (14) to the frame, the sensing beam (16) being distorted by pivoting movement of the mass (14). Distortion of the sensing beam on pivoting movement of the mass is determined, from which the acceleration of the accelerometer may be determined.

Abstract: A solid state angular rate sensor is fabricated by preparation of a disc-shaped base structure (10) having first and second outer layers of a piezo-electric ceramic material, built up from a number of layers of a ceramic sheet or film that is capable of being tape-cast. The layers are then sintered and an inner layer of metallic material is provided between the outer layers, to complete a piezo-electric base structure having an inner electrode (15) between the sintered outer layers. Arrays of electrode structures are provided on the outer layers of the base structure (10), the electrodes radiating from the central region 14 of the base structure (10) and being equi-spaced around the outer edge of the disc (19).

Abstract: A method of and apparatus for scale factor compensation for piezo-electric rate sensors maintains the magnitude of vibration at a primary pick-off point substantially constant to enable one of the variables of a vibrating structure--the piezo-electric charge coefficient .beta. to be determined, and thereby enables variation of the scale factor of the sensor from a calibrated value to be determined. This enables correction of the sensor output by a computational scale factor control unit to ensure that the output therefrom allows for a more accurate sensor. Thus, sensors are provided for applications requiring a higher degree of accuracy than they were previously able to provide for.

Abstract: A vibrating planar ring or hoop-like structure is disclosed. The structure is suspended in space by a suitable support mount for detecting turning rate, linear acceleration and angular acceleration. Turning rate is sensed by detecting vibrations coupled by Coriolis forces, whereas linear acceleration and angular acceleration are sensed by lateral, vertical and rocking movement of the entire ring or hoop-like structure within its mount.

Abstract: This invention relates to a single axis solid state attitude sensor in which, the spatial orientation of a resonant rode on a resonant body is maintained in alignment with the inertial angle K8 of the resonant body.