The invention relates to a method for measuring a velocity of an object surface (O) relative to a sensor (1) with at least one light-sensitive element (2) according to the spatial frequency filtering method, wherein the light-sensitive element (2) is read at time intervals, and wherein the spatial frequency filter is designed as at least one masking grating having a variable grating constant. The method according to the invention is characterized in that the relative velocity is first measured using a first grating constant k1 having a large period length and/or over a short observation time period t1 (rough measurement) and then the measurement of the relative velocity is repeated for a more exact determination using a second grating constant k2 having a small period length and/or over a long observation time period t2 (fine measurement). The invention further relates to a sensor for velocity measurement.
G01P 3/36 - Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light
G01P 3/68 - Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
2.
METHOD FOR OPTICALLY MEASURING SPEEDS AND SENSOR FOR OPTICALLY MEASURING SPEEDS
The invention relates to a method for measuring a speed of an object surface (O) relative to a sensor (1), wherein the sensor (1) has a plurality of light-sensitive elements (2) which are arranged at a distance from one another and are read at intervals of time. The invention is characterized in that the measurement is carried out according to the spatial frequency filtering method (SFV) and according to the image processing method (BW), the frequency signal (f) determined in the spatial frequency filtering method (SFV) is checked with respect to the frequency value determined and/or with respect to at least one quality feature, and, in the event of the frequency signal (f) being below a frequency value which can be defined and/or the frequency signal (f) not reaching a quality feature value which can be defined, the value determined in the image processing method (BW) is selected in order to determine the relative speed. The invention also relates to a sensor (1) for measuring a speed of an object surface (O) relative to the sensor (1).
G01P 3/36 - Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light
G01P 3/68 - Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
G01P 3/80 - Devices characterised by the determination of the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means
G01S 17/58 - Velocity or trajectory determination systemsSense-of-movement determination systems
The invention relates to a method for length and/or velocity measurement, in particular for positioning tasks, in which an optical sensor carries out a length and/or velocity measurement on a measurement object in a contactless manner, wherein the optical sensor carries out the length and/or velocity measurement via an image processing method, via a spatial frequency filter method and/or by way of a laser Doppler method and reference markings are recognized by the optical sensor, and to a corresponding apparatus. The object of providing a simple method and a simple apparatus for length and/or velocity measurement which offers a higher degree of measurement reliability with the result that it can also be used in safety-relevant areas of application is achieved by evaluation means carrying out reference marking recognition operations and by a plausibility test being carried out, in which a signal is generated as a function of the result of the plausibility test.
G01P 3/68 - Devices characterised by the determination of the time taken to traverse a fixed distance using optical means, i.e. using infrared, visible, or ultraviolet light
G01P 3/36 - Devices characterised by the use of optical means, e.g. using infrared, visible, or ultraviolet light
G01P 3/80 - Devices characterised by the determination of the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means
G01P 21/02 - Testing or calibrating of apparatus or devices covered by the other groups of this subclass of speedometers
G01D 5/347 - Mechanical means for transferring the output of a sensing memberMeans for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for convertingTransducers not specially adapted for a specific variable using optical means, i.e. using infrared, visible or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells using displacement encoding scales
G01S 17/50 - Systems of measurement based on relative movement of target
G01C 22/00 - Measuring distance traversed on the ground by vehicles, persons, animals or other moving solid bodies, e.g. using odometers or using pedometers
09 - Scientific and electric apparatus and instruments
42 - Scientific, technological and industrial services, research and design
Goods & Services
Signalling and checking (supervision) apparatus and instruments; electric, opto-electronic, contact or non-contact protective equipment for safeguarding edges, surfaces and spaces, in particular safety edges and safety mats; electric pressure switches; electronic, electric transmitters, in particular opto-electronic angle encoders, opto-electronic shaft encoders, electronic position sensors, electronic tilt sensors; electronic, electric controls, electric transformers and electric connector cables for the aforesaid goods. Engineering services; updating and rental of computer programs; computer programming; technical project studies.
