A capacitance measurement system precharges first terminals (21-0 . . . 21-k . . . 21-n) of a plurality of capacitors (25-0 . . . 25-k . . . 25), respectively, of a CDAC (capacitor digital-to-analog converter) (23) included in a SAR (successive approximation register) converter (17) to a first voltage (V.sub.DD) and pre-charges a first terminal (3-j) of a capacitor (C.sub.SENj) to a second voltage (GND). The first terminals are coupled to the first terminal of the capacitor to redistribute charges therebetween so as to generate a first voltage on the first terminals and the first terminal of the capacitor, the first voltage being representative of a capacitance of the first capacitor (C.sub.SENj). A SAR converter converts the first voltage to a digital representation (DATA) of the capacitor. The capacitance can be a touch screen capacitance.

A capacitance measurement system precharges first terminals (21-0 . . . 21-k . . . 21-n) of a plurality of capacitors (25-0 . . . 25-k . . . 25), respectively, of a CDAC (capacitor digital-to-analog converter) (23) included in a SAR (successive approximation register) converter (17) to a first voltage (V.sub.DD) and pre-charges a first terminal (3-j) of a capacitor (C.sub.SENj) to a second voltage (GND). The first terminals are coupled to the first terminal of the capacitor to redistribute charges therebetween so as to generate a first voltage on the first terminals and the first terminal of the capacitor, the first voltage being representative of a capacitance of the first capacitor (C.sub.SENj). A SAR converter converts the first voltage to a digital representation (DATA) of the capacitor. The capacitance can be a touch screen capacitance.

A multiturn rotary encoder includes: a single-turn unit, including a code carrier that is able to be scanned by a single-turn scanner in order to generate single-turn position signals, and a single-turn evaluation unit for processing the single-turn position signals to form at least one single-turn code word that indicates the absolute position of an input shaft within one revolution; a first multiturn unit dependent on a power supply, including at least a first multiturn code carrier that is able to be scanned by a first multiturn scanner in order to generate first multiturn position signals, and a first multiturn evaluation unit for processing the first multiturn position signals to form a first multiturn code word that indicates the number of revolutions executed by the input shaft; and a second multiturn unit independent of a power supply, including at least a second multiturn code carrier that is able to be scanned by a second multiturn scanner in order to generate second multiturn position signals, and a second multiturn evaluation unit for processing the second multiturn position signals to form a second multiturn code word which likewise indicates the number of revolutions executed by the input shaft. The value of the first multiturn code word of the first multiturn unit in an initialization phase after the power supply of the multiturn rotary encoder has been switched on is able to be referenced with the value of the second multiturn code word.

A multiturn rotary encoder includes: a single-turn unit, including a code carrier that is able to be scanned by a single-turn scanner in order to generate single-turn position signals, and a single-turn evaluation unit for processing the single-turn position signals to form at least one single-turn code word that indicates the absolute position of an input shaft within one revolution; a first multiturn unit dependent on a power supply, including at least a first multiturn code carrier that is able to be scanned by a first multiturn scanner in order to generate first multiturn position signals, and a first multiturn evaluation unit for processing the first multiturn position signals to form a first multiturn code word that indicates the number of revolutions executed by the input shaft; and a second multiturn unit independent of a power supply, including at least a second multiturn code carrier that is able to be scanned by a second multiturn scanner in order to generate second multiturn position signals, and a second multiturn evaluation unit for processing the second multiturn position signals to form a second multiturn code word which likewise indicates the number of revolutions executed by the input shaft. The value of the first multiturn code word of the first multiturn unit in an initialization phase after the power supply of the multiturn rotary encoder has been switched on is able to be referenced with the value of the second multiturn code word.

This invention concerns remote sensor networks, and particularly energy management for wireless sensor networks. In a first aspect the invention is a wireless sensor node specified to operate for a given lifetime, including an onboard computer system and a set of one or more associated sensors. The computer system operates to periodically sample data from each sensor of the set of associated sensors, and to store a multi-state model representing one or more phenomena described by the collected data. And, the computer system operates to calculate a value associated with movement of the phenomena between the states of the multi-state model, and to adjust the rate of sampling of one or more of the set of associated sensors depending on the calculated value. In other aspects the invention is a network of sensor nodes and a method of operation.

This invention concerns remote sensor networks, and particularly energy management for wireless sensor networks. In a first aspect the invention is a wireless sensor node specified to operate for a given lifetime, including an onboard computer system and a set of one or more associated sensors. The computer system operates to periodically sample data from each sensor of the set of associated sensors, and to store a multi-state model representing one or more phenomena described by the collected data. And, the computer system operates to calculate a value associated with movement of the phenomena between the states of the multi-state model, and to adjust the rate of sampling of one or more of the set of associated sensors depending on the calculated value. In other aspects the invention is a network of sensor nodes and a method of operation.

A system for positioning post sleeves is provided including a plurality of post sleeve positioning devices and a spacing mechanism. Each post sleeve positioning device is configured to receive a respective post sleeve and to enable selective adjustment of a position and orientation of the respective post sleeve. The spacing mechanism is coupleable between the pair of post sleeve positioning devices to determine or control the position and orientation of the post sleeve received by one of the pair of post sleeves positioning devices relative to the post sleeve received by the other one of the pair of post sleeve positioning devices. Related systems and methods are also provided.

A system for positioning post sleeves is provided including a plurality of post sleeve positioning devices and a spacing mechanism. Each post sleeve positioning device is configured to receive a respective post sleeve and to enable selective adjustment of a position and orientation of the respective post sleeve. The spacing mechanism is coupleable between the pair of post sleeve positioning devices to determine or control the position and orientation of the post sleeve received by one of the pair of post sleeves positioning devices relative to the post sleeve received by the other one of the pair of post sleeve positioning devices. Related systems and methods are also provided.

A calibration target comprises a target pattern plane having a planar surface and a plurality of markers disposed on the planar surface. An optical axis of the imaging system is at a first angle with respect to the planar surface of the target pattern plane when the calibration target is being used to calibrate the imaging system. The plurality of markers is pre-warped in size and aspect ratio using a set of trigonometric functions that use the first angle and a distance from the imaging system to the marker, so that each of the plurality of markers appears a substantially same size as all others of the plurality of markers when viewed by the imaging system at the first angle. The plurality of markers includes a plurality of localizer features that have known relative positions on the target pattern plane and are used to determine an orientation for each marker.

A calibration target comprises a target pattern plane having a planar surface and a plurality of markers disposed on the planar surface. An optical axis of the imaging system is at a first angle with respect to the planar surface of the target pattern plane when the calibration target is being used to calibrate the imaging system. The plurality of markers is pre-warped in size and aspect ratio using a set of trigonometric functions that use the first angle and a distance from the imaging system to the marker, so that each of the plurality of markers appears a substantially same size as all others of the plurality of markers when viewed by the imaging system at the first angle. The plurality of markers includes a plurality of localizer features that have known relative positions on the target pattern plane and are used to determine an orientation for each marker.