摘要:
The invention relates to an apparatus for measuring a distance. A self-mixing interference (SMI) unit (2) generates an SMI signal, wherein the SMI unit comprises a laser (3) emitting a first laser beam (4) for being directed to an object (5) and wherein the SMI signal depends on an interference of the first laser beam and a second laser beam (6) reflected by the object. A peak width determination unit (8) determines a peak width of the SMI signal, and a distance determination unit (9) determines a distance between the object and the SMI unit depending on the determined peak width of the SMI signal. Since the distance is determined depending on the peak width of the SMI signal, without requiring a laser driving current modulation, advanced electronics for modulating the driving current of the laser are not needed. This reduces the technical efforts needed for determining the distance.
摘要:
The present invention refers to a method of operating a self-mixing interference sensor and a corresponding self-mixing interference sensor device. In the method the laser (1) of the device is controlled to periodically emit a laser pulse followed by an emission period of laser radiation having a lower amplitude. The pulse width of the laser pulse is selected such that the pulse after reflection at the object (3) re-enters the laser (1) during the emission period of laser radiation with lower amplitude. The corresponding SMI signal has an increased signal to noise ratio.
摘要:
A sensor module (1) for measuring the distance to a target and/or the velocity of the target (50), the sensor module (1) comprising at least one laser source (100), at least one detector (200) being adapted to detect modulated laser light and at least one control element the control element (400) being adapted to vary the focus point of the laser light and/or the intensity of the laser light and/or the direction of the laser light. The control of the laser light emitted by the laser source (100) either by active optical devices as variable focus lenses or controllable attenuators or passive optical elements in combination with arrays of laser sources (100) and detectors (200) enable flexible and robust sensor modules.
摘要:
The invention relates to an apparatus (1) for determining a flow property of a fluid (2). The apparatus comprises a distance and velocity determination unit (3) for determining distances of elements of the fluid to the distance and velocity determination unit (3) and for determining velocities of the elements at the same time based on a self-mixing interference signal. The apparatus (1) comprises further a flow determination unit (4) for determining the flow property of the fluid (2) based on at least one of the determined distances and velocities. This allows determining the flow property, even if the fluid (2) is optically thick.
摘要:
An optical sensor (600) for detecting the movement of an object relative to the position of the optical sensor (600), using self-mixing interference, is described. The optical sensor (600) comprises a laser (100), a detector (200) and a filter device (500). The filter device (500) suppresses measurement signals generated by means of the detector (200) when movements of the object at a velocity below a defined threshold value cause the measurement signals. The optical sensor (600) may be used in a switch in order to enable selective switching depending on the velocity of the movement of the object.
摘要:
An apparatus, method and computer program for measuring a distance using a self-mixing interference (SMI) unit that generates an SMI signal. The SMI unit comprises a laser emitting a first laser beam directed to an object and wherein the SMI signal depends on an interference of the first laser beam and a second laser beam reflected by the object. A peak width determination unit determines a peak width of the SMI signal, and a distance determination unit determines a distance between the object and the SMI unit depending on the determined peak width of the SMI signal. Since the distance is determined depending on the peak width of the SMI signal, without requiring a laser driving current modulation, advanced electronics for modulating the driving current of the laser are not needed. This reduces the technical efforts needed for determining the distance.
摘要:
The method is based on a determination of the orientation of the sensor to the surface moving with respect to the sensor and then acquiring data where the lateral velocity is small and the forward velocity is large. Then, the orientation of the sensor with respect to the direction of the forward velocity is determined and the velocity data subsequently measured are corrected using the measured orientation of the sensor with respect to the reference surface and the forward velocity direction.
摘要:
The method is based on a determination of the orientation of the sensor to the surface moving with respect to the sensor and then acquiring data where the lateral velocity is small and the forward velocity is large. Then, the orientation of the sensor with respect to the direction of the forward velocity is determined and the velocity data subsequently measured are corrected using the measured orientation of the sensor with respect to the reference surface and the forward velocity direction.
摘要:
The invention relates to a velocity determination apparatus (1) for determining a velocity of an object (2). A Doppler frequency measuring unit is adapted to measure Doppler frequencies in at least three different frequency directions, wherein a Doppler frequency calculation unit is adapted to calculate a Doppler frequency for a calculation frequency direction being similar to one of the at least three different frequency directions depending on the Doppler frequencies measured for at least two further frequency directions of the at least three different frequency directions. The velocity can then be determined depending on the calculated Doppler frequency and the measured Doppler frequencies. Since in the calculation frequency direction the measured Doppler frequency is not needed for determining the velocity, a reliable velocity can be determined also in the calculation frequency direction, even if the measurement of the Doppler frequency in this calculation frequency direction is disturbed.
摘要:
A sensor module (1) for measuring the distance to a target and/or the velocity of the target (50), the sensor module (1) comprising at least one laser source (100), at least one detector (200) being adapted to detect modulated laser light and at least one control element the control element (400) being adapted to vary the focus point of the laser light and/or the intensity of the laser light and/or the direction of the laser light. The control of the laser light emitted by the laser source (100) either by active optical devices as variable focus lenses or controllable attenuators or passive optical elements in combination with arrays of laser sources (100) and detectors (200) enable flexible and robust sensor modules.