Inductive sensor

About: Inductive sensor is a research topic. Over the lifetime, 2282 publications have been published within this topic receiving 21984 citations.

Recursive Frequency Allocation Scheme in Wireless Power Transfer and Magnetic Induction Communication Systems

Abstract: Magnetic induction applications mostly rely on resonance for inducing maximum magnetic fields to system loads and hence for each resonant frequency dedicated circuits are required. Unfortunately, the frequency responses of such inductive systems manifest several peaks (frequency splitting) when their coupling coefficients are equal to or larger than critical coupling. Such frequency responses with several peaks are detrimental when the objective is to transfer maximum energy. Frequency splitting between inductive coils have been seen to date as detrimental to wireless power transfer and inductive communication systems. In this paper it is demonstrated that frequency splitting is a welcome phenomenon with advantage in the design of inductive filter banks and multi-frequency inductive systems. The centre frequencies of the filter banks result from split bands of inductive systems. This phenomenon is applied in conjunction with an innovative recursive algorithm to design inductive filter banks. The filters straddle both sides of the resonant frequency position and can be resolved individually.

Measurement of knock and its analysis on turbocharged 600cc formula SAE boost pressure control and sensor signal conditioning

Abstract: Turbocharging of a FSAE 600cc engine required analysis of knock at high engine speeds. Knock testing on this engine was performed at 8000 and 10000 rpm. The engine was boosted to 150 kPa which was controlled with a Proportional Integral Derivative (PID) controller that actuated an external wastegate. In-cylinder pressure measurements were acquired at 200 kHz. Apart from in-cylinder pressure the other recorded channels were: crank sensor, cam sensor, spark timing and knock sensor. Data Streaming in LabVIEW® was used to acquire the data for the required lengths of time. The streamed data was then post processed also in LabVIEW. The in-cylinder pressure measurement was signal conditioned with the typical charge-amplifier used with piezo sensors. However the other measurements all required some form of in-house signal conditioning which are discussed in this paper. The crank sensor signal was coming from a mechanically modified crank sensor sprocket that did not have any missing teeth. This signal replaced the typical crank-shaft encoder typically used in conjunction with in-cylinder pressure measurements. The cam sensor was an in-house design using an inductive sensor triggered by a magnet inserted in a bolt attached onto the cam drive sprocket. This signal had to be amplified due to the low signal level during cranking. The crank sensor signal together with the cam sensor signal were used as the basis for a software generated crank angle that was required to calculate the instantaneous volume of the engine cylinder. The spark timing signal was a logical AND from all four low voltage (12V) spark plug output commands from the Engine Control Unit (ECU). This signal was required to analyze the effect of spark advance on knock. Finally the knock sensor signal was conditioned to provide a low output impedance to avoid ‘ghosting’ in the National Instruments data acquisition.

Identity recognition device and identity recognition method

Abstract: The invention provides an identity recognition device and an identity recognition method. The identity recognition device comprises a substrate with a groove part. A contact type recognition unit is arranged in the groove part of the base body and can recognize the identity of the user after the designated part of the user makes contact with the contact type recognition unit. An inductive sensor is arranged on the base body and is used for sensing whether a specified part extends into the groove part or not. A driving unit is arranged on the base body and is connected with the inductive sensor. A cleaning unit is arranged on the base body and is connected with the driving unit; and when the inductive sensor senses the designated part, the driving unit drives the cleaning unit to clean thefingers. An identity recognition device can temporarily clean fingers of a user and remove sweat or dust and the like on the surfaces of the fingers, so that the surfaces of the fingers are kept clean, and the recognition accuracy of a system is improved.

Inductive incremental displacement sensor for determining displacement of object relative to another object, particularly for feed through, has two sensor units with one inductive sensor and another inductive sensors

Abstract: The inductive incremental displacement sensor has two sensor units (40,50) with an inductive sensor (41,51) and another inductive sensors (42,52). The two sensor units supply a switching signal that belongs to a conductive area (32) of the partition groove, if the difference or the ratio of the detection signals of the inductive sensors is smaller than the determined threshold. The detection signals of the inductive sensors are generated by the conducting areas. Independent claims are also included for the following: (1) a method for determining the displacement of an object relative to another object (2) an inductive sensor unit for space independent determination of a lateral position of an object, particularly a conducting area or a periodically graduated track of an incremental encoder.

A Design of Miniature Strong Anti-jamming Proximity Sensor

Abstract: This paper contains a design of miniature proximity sensor used in the my electric prosthetic hand to perceive the approaching distance of grabbing objects. An infrared sensor is used as a probe in this sensor which adopts the principle that the infrared reflects the light intensity. The compact structure of the sensor can make it suitable for a fingertip of a prosthetic hand. There is a modulation-demodulation part added up to its signal processing circuitry to obtain the stable output signal filtered and amplified by the modulation-demodulation, the voltage of the signal will change according to the proximity distance. The result of the experiment shows that the sensor has strong anti-jamming ability, and it is very competent for the my electric prosthetic hand.