The present invention discloses a quasi-zero-stiffness (QZS) based six-degree-of-freedom (6-DOF) absolute displacement and attitude measurement device. A lower end coil and an upper end coil are respectively charged with currents in the opposite directions; The electromagnetic field and the magnetic fields of an upper magnet and a lower magnet per se are mutually acted to produce an electromagnetic stiffness opposite to the stiffness of a spring. The stiffness of the whole leg is close to zero stiffness. When the to-be-measured platform generates space motion, the reference platform is in the stationary state. At this point, the deformation amounts of the six legs can be measured by laser displacement sensors. The six deformation amounts are respectively inputted into the displacement and attitude resolver, and by forward kinematic solution of the 6-DOF device, the displacement and the attitude of the to-be-measured platform can be obtained.

A method of detecting defects or deterioration in the sidewalls of can bodies during production of the can bodies within a can bodymaker. Each can body is formed by pushing a cup, mounted on a punch of a reciprocating ram, through one or more dies contained within a tool pack of the bodymaker. The method comprises: obtaining output signals from one or more eddy current sensors arranged around the ram axis outside of the tool pack and adjacent to an exit end of the tool pack; processing the output signals to detect passage of open ends of can body sidewalls past the sensor(s) and thereby determine measures of the heights or thicknesses of can body sidewalls; and analysing the determined measures to identify can body sidewall defects or deterioration.

Methods and apparatus for sensing target position by generating a signal by energizing a shaped coil with an AC signal. A sensor receives a signal reflected by a target in response to the signal from the shaped coil, wherein the shaped coil has a first width, and wherein the sensor includes a first sensing element aligned with the shaped coil at the first width, wherein a ratio of the first width and a distance from the sensor to the target is about three-to-one. The received signal can be processed to determine position information of the target. In some embodiments, a shaped coil can have a trapezoidal shape and sensors aligned with the coil to select a sensor based upon target to sensor distance.

A conveyor belt condition monitoring apparatus is U-shaped, with two parallel arms arranged to extend across a conveyor belt from the side. The arms include ultrasonic sensors arranged to measure the distance to respective surfaces of the conveyor belt. One arm includes an eddy-current sensor arranged to measure the distance to a metallic core of the belt. The apparatus is arranged to be moved across the belt to provide a profile of belt condition across the width of the belt.

Methods and apparatus for sensing target position by generating a signal by energizing a shaped coil with an AC signal. A sensor receives a signal reflected by a target in response to the signal from the shaped coil, wherein the shaped coil has a first width, and wherein the sensor includes a first sensing element aligned with the shaped coil at the first width, wherein a ratio of the first width and a distance from the sensor to the target is about three-to-one. The received signal can be processed to determine position information of the target. In some embodiments, a shaped coil can have a trapezoidal shape and sensors aligned with the coil to select a sensor based upon target to sensor distance.

A conveyor belt condition monitoring apparatus is U-shaped, with two parallel arms arranged to extend across a conveyor belt from the side. The arms include ultrasonic sensors arranged to measure the distance to respective surfaces of the conveyor belt. One arm includes an eddy-current sensor arranged to measure the distance to a metallic core of the belt. The apparatus is arranged to be moved across the belt to provide a profile of belt condition across the width of the belt.

The present invention discloses a quasi-zero-stiffness (QZS) based six-degree-of-freedom (6-DOF) absolute displacement and attitude measurement device. A lower end coil and an upper end coil are respectively charged with currents in the opposite directions; The electromagnetic field and the magnetic fields of an upper magnet and a lower magnet per se are mutually acted to produce an electromagnetic stiffness opposite to the stiffness of a spring. The stiffness of the whole leg is close to zero stiffness. When the to-be-measured platform generates space motion, the reference platform is in the stationary state. At this point, the deformation amounts of the six legs can be measured by laser displacement sensors. The six deformation amounts are respectively inputted into the displacement and attitude resolver, and by forward kinematic solution of the 6-DOF device, the displacement and the attitude of the to-be-measured platform can be obtained.

The present invention reveals a distance sensor comprising: a signal receiving unit, an electromagnetic wave transmitting unit, and a magnetic signal transmitting unit; wherein the signal transmitting unit is adapted to transmit to the signal receiving unit a sensed distance between the signal receiving unit and the magnetic signal transmitting unit, wherein the magnetic signal transmitting unit further comprises an electromagnetic wave receiving unit and an electromagnetic wave-to-electric power converter, and wherein the electromagnetic wave receiving unit receives electromagnetic waves transmitted from the electromagnetic wave transmitting unit to operate the magnetic signal transmitting unit.

A crop canopy height detection system for an agricultural machine includes a plurality of contact sensors and a processing unit. The contact sensors are spaced apart across the front of the machine and are each operable to detect physical contact with a crop being harvested by the machine and to generate a corresponding crop contact signal. The processing unit receives the crop contact signals from the contact sensors and determines a canopy height of the crop based on the crop contact signals.

A method of detecting defects or deterioration in the sidewalls of can bodies during production of the can bodies within a can bodymaker. Each can body is formed by pushing a cup, mounted on a punch of a reciprocating ram, through one or more dies contained within a tool pack of the bodymaker. The method comprises: obtaining output signals from one or more eddy current sensors arranged around the ram axis outside of the tool pack and adjacent to an exit end of the tool pack; processing the output signals to detect passage of open ends of can body sidewalls past the sensor(s) and thereby determine measures of the heights or thicknesses of can body sidewalls; and analysing the determined measures to identify can body sidewall defects or deterioration.