Inductive sensor

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

Improvement in sensitivity of an inductive oil palm fruit sensor.

Abstract: Among palm oil millers, the ripeness of oil palm Fresh Fruit Bunch (FFB) is determined through visual inspection. To increase the productivity of the millers, many researchers have proposed with a new detection method to replace the conventional one. The sensitivity of such a sensor plays a crucial role in determining the effectiveness of the method. In our preliminary study a novel oil palm fruit sensor to detect the maturity of oil palm fruit bunches is proposed. The design of the proposed air coil sensor based on an inductive sensor is further investigated to improve its sensitivity. This paper investigates the results pertaining to the effects of the air coil structure of an oil palm fruit sensor, taking consideration of the used copper wire diameter ranging from 0.10 mm to 0.18 mm with 60 turns. The flat-type shape of air coil was used on twenty samples of fruitlets from two categories, namely ripe and unripe. Samples are tested with frequencies ranging from 20 Hz to 120 MHz. The sensitivity of the sensor between air to fruitlet samples increases as the coil diameter increases. As for the sensitivity differences between ripe and unripe samples, the 5 mm air coil length with the 0.12 mm coil diameter provides the highest percentage difference between samples and it is amongst the highest deviation value between samples. The result from this study is important to improve the sensitivity of the inductive oil palm fruit sensor mainly with regards to the design of the air coil structure. The efficiency of the sensor to determine the maturity of the oil palm FFB and the ripening process of the fruitlet could further be enhanced.

A New Method of Inductive Sensor Impedance Measurement Applied to the Identification of Vehicle Parameters

Abstract: Inductive loop sensors are widely used f or detection of presence, measurement of parameters as well as classification of vehicles. Vehicle classification may be performed based on their magnetic profiles. The magnetic profile is a signal which is proportional to the resultant of an impedance cha nge of the sensor, caused by the measured object (the changes are minor - of the order of 1%). Generator and bridge circuits are most commonly used as conditioning circuits for such sen sors. As a result we can obtain one output signal proportional to total changes of sensor parameters (R and L). In this pa per, a modified bridge circuit that allows independent measurement of the components (R and L) of the sensor’s impedance, has been proposed. With that provided, it is possible to receive broader informa tio n on the object, which allows higher classification resolution. This paper provides the concept of a ci rcuit, model testing results, processing algorithms used and the test results of a real circuit.

Touch display screen electronic price tag based on human body induction and operating method thereof

Abstract: The invention belongs to the technical field of price tags, and provides a touch display screen electronic price tag based on human body induction. The touch display screen electronic price tag based on human body induction comprises a shell, a host, a touch display screen, a voice device, a power source and a loudspeaker, wherein a human body inductive sensor, the host, the touch display screen, the voice device, the loudspeaker and the power source are arranged in the shell, the host is connected with the human body inductive sensor, and is used for receiving information indicating that a person gets close to the human body inductive sensor or is far away from the human body inductive sensor, and transmitting the inductive information, the touch display screen is connected with the host, is used for receiving the information indicating that the person gets close to the human body inductive sensor or is far away from the human body inductive sensor, is automatically lightened and displays related information of products when the person gets close to the human body inductive sensor, and can automatically sleep when the person is far away from the human body inductive sensor, the voice device and the power source are connected with the host, and the loudspeaker is connected with the voice device. The touch display screen electronic price tag based on human body induction has the advantages that the automatic lightening or sleep function and the automatic voice broadcast function are achieved when a human body gets close to the human body inductive sensor and is far away from the human body inductive sensor, product diversification introductions are achieved through the touch display screen, manpower is saved, the cost is reduced, and product information can be conveniently updated or changed.

Non-ferrite structures for inductive power transfer

Abstract: An inductive power transfer apparatus suitable for producing a magnetic field for inductive power transfer is disclosed. The apparatus has three or more coils arranged such that when energised with a power source, magnetic fields produced by each coil augment each other on a first surface and substantially weaken each other on a second surface. The first and second surfaces have an obverse relationship to each other. Also disclosed is a roadway inductive power transfer module suitable for producing a magnetic field for inductive power transfer to a vehicle using the roadway, and an Inductive power transfer apparatus suitable for receiving a magnetic field for inductive power transfer.

Timer-Based Demodulator for AM Sensor Signals Applied to an Inductive Displacement Sensor

Abstract: This paper proposes a novel method for demodulating low-frequency amplitude-modulated (AM) signals provided by sensors. The method relies on a digital timer that carries out the demodulation and digitization simultaneously, without requiring a rectifier, a mixer, a low-pass filter, or an analog-to-digital converter. This timer-based demodulator extracts the amplitude of the AM signal by measuring the period of a reference signal that is altered by the AM signal itself. The period measurement undergoes a deviation that carries information about the amplitude of the AM signal. The feasibility and also the limitations, such as the nonlinearity and aliasing effects, of this novel demodulator are proved theoretically and experimentally. The concept is also applied to measure an inductive displacement sensor in a range of ±30 mm. A nonlinearity error of 0.5% full-scale span and a resolution of 9 bits are achieved for an overall measuring time of 100 ms.