CROSS REFERENCE TO RELATED APPLICATIONS

The present application is the U.S. national stage application of international application PCT/EP2018/072858 filed Aug. 24, 2018, which international application was published on Mar. 14, 2019 as International Publication WO 2019/048257 A1. The international application claims priority to German Patent Application 10 2017 215 686.4 filed Sep. 6, 2017.

FIELD OF THE INVENTION

The present invention relates to a motion sensor device, a method for operating same, and a lighting system having the motion sensor device.

BACKGROUND OF THE INVENTION

PIR sensors (pyroelectric/passive infrared sensors) serve for detecting temperature changes based on pyroelectricity, a property of some piezoelectric crystals of converting a temperature change into electrical polarization or charge separation.

Pyroelectric crystals react to temperature changes, which given a suitable absorption coating of the crystal can result from an incident radiation of a desired wavelength, in particular infrared radiation.

PIR sensors for motion detectors usually have a plurality (two or four) of adjacent sensor elements which are connected in opposite polarity to one another. Exposure of adjacent sensor elements consequently causes positive or negative voltage pulses. If exposed simultaneously, they cancel each other out; given sequential exposure, voltage edges are formed that can be detected well.

A detection region of motion detectors can be spatially expanded into a plurality of detection zones via a lens arrangement with a plurality of lenses, upstream of the PIR sensor. Each lens of the lens arrangement deflects the thermal radiation from one detection zone onto at least one of the plurality of sensor elements.

The formation of voltage edges that can be detected well is supported in that detection zones are spatially separated in relation to each other in such a way that an object which is warmer than the background is optimally only ever detected in one detection zone, or by the sensor element associated therewith, when the object passes through the detection region.

The plurality of adjacent sensor elements of known PIR sensors enable a detection that a movement is present in the detection region, but not in which direction this movement takes place.

SUMMARY OF THE INVENTION

There is therefore a need for motion sensor devices, methods for operating the same, and lighting systems having the motion sensor devices, which enable a detection of the direction of a detected motion.

This object is achieved according to the invention by a motion sensor device described herein.

A motion sensor device in accordance with a first aspect comprises: a PIR sensor having a plurality of sensor elements arranged adjacent to each other, the active sensor surfaces of which form a detection region of the PIR sensor; and an optical unit which is configured to image a detection region of the motion sensor device, said detection region comprising detection zones, on the detection area of the PIR sensor. The detection zones in the detection region of the motion sensor device have a spatially periodic arrangement with direction-dependent periodicity.

Such motion sensor devices advantageously enable recognition of a direction of a detected movement, which is based on an evaluation of the direction-dependent periodicity of the spatially periodic arrangement of the detection zones in the detection region of the motion sensor device. Furthermore, conventional PIR sensors can be used in such motion sensor devices.

In the sense of this application, “adjacent” is understood to mean a laterally opposite arrangement with a spatial separation, as is provided in particular between sensor elements of conventional PIR sensors.

An “active sensor surface” in the sense of this application is understood to mean that such a surface is permeable to radiation which contributes to a measurement signal of the PIR sensor.

In the sense of this application, an “optical unit” is understood to mean a lens arrangement having a plurality of lenses, or a mirror arrangement having a plurality of mirrors, facing toward the detection region of the motion sensor device. Such an optical unit can be produced from thermoplastic, for example.

A “spatially periodic arrangement” in the sense of this application is understood to mean a repeated, in particular duplicate or multiple, arrangement in at least one spatial direction.

“Direction-dependent periodicity” in the sense of this application is understood to mean a spatially periodic arrangement in two different spatial directions with repetition at differently frequent intervals with respect to the different spatial directions.

According to one exemplary embodiment, the motion sensor device further comprises a signal processing unit configured to determine the direction-dependent periodicity of the detection zones in the detection region of the motion sensor device.

Such a signal processing unit advantageously makes it possible to recognize a direction of a detected movement and/or a stop location of objects moving in the detection region of the motion sensor device.

A signal processing unit in the sense of this application is understood to mean a unit which is configured to receive, analyze, and convert input signals into output signals having an information content of interest. In particular, the signal processing unit is configured to receive, analyze, and convert measurement signals of the PIR sensor into output signals which indicate one or more movements, movement directions, and/or one or more stop locations of objects moving in the detection region of the motion sensor device.

According to one exemplary embodiment, the signal processing unit is further configured to form differential signals from output signals of the sensor elements between pairs of sensor elements of the PIR sensor that are arranged adjacent to one another, and/or to determine frequency components in the differential signals or the output signals.

Advantageously, such a signal processing unit enables a detection of frequency components, for example by means of spectral analysis, in those differential or output signals which conventional PIR sensors supply.

According to one exemplary embodiment, the detection zones have a spatially periodic arrangement with direction-dependent periodicity in accordance with first and second directions which are orthogonal to one another in the detection region of the motion sensor device.

Such a spatially periodic arrangement with direction-dependent periodicity in accordance with first and second directions which are orthogonal to one another advantageously spans a Cartesian coordinate system in a walking or moving surface that is detected by the detection region of the motion sensor device. All directions of movement in a plane of the walking or moving surface can be described on the basis of this coordinate system.

According to one exemplary embodiment, the optical unit is configured to image groups of the detection zones via a respective imaging in the detection area of the PIR sensor.

Advantageously, a group-by-group imaging of the detection zones into the detection area of the PIR sensor limits a number of the lenses which the optical unit must comprise, since one lens is required per image or group.

According to one exemplary embodiment, a number of the detection zones of a respective one of the groups of detection zones corresponds to a number of the sensor elements of the PIR sensor.

According to one exemplary embodiment, an arrangement of the detection zones corresponds to the respective group of the detection zones of the arrangement of the sensor elements of the PIR sensor arranged that are adjacent to one another.

Advantageously, respective imaging of such groups of detection zones is easily converted into corresponding lenses for the optical unit.

According to one exemplary embodiment, the optical unit is configured to superimpose a plurality of the groups of the detection zones in the detection area of the PIR sensor.

Such an optical unit with a plurality of lenses, wherein each one of the plurality of lenses produces an imaging of one of the plurality of groups of the detection zones, advantageously enables a detection of a number of detection zones which is an integer multiple of the number of the sensor elements of the PIR sensor.

According to one exemplary embodiment, the optical unit is configured to scale the respective group of the detection zones for imaging in the detection area of the PIR sensor in a first dimension, which first dimension extends in the first direction in the detection region of the motion sensor device.

According to one exemplary embodiment, the optical unit is configured to scale the respective group of the detection zones for imaging in the detection area of the PIR sensor in a second dimension orthogonal to the first dimension, which second dimension extends in the second direction in the detection region of the motion sensor device.

Such an optical unit advantageously enables a variation of a spatial periodicity—or, in other words, of a spatial frequency—of the spatially periodic arrangement of the detection zones in the detection region of the motion sensor device in the first direction, and/or in the second direction orthogonal thereto, in the walking or moving surface detected by the detection region of the motion sensor device.

A “spatial frequency” in the sense of this application is understood to mean a number of periods per unit of length in one spatial direction.

According to one exemplary embodiment, the optical unit is configured to completely image all of the detection zones of the detection region of the PIR sensor into the detection area of said PIR sensor.

Such an optical unit advantageously maximizes a sensitivity of the motion sensor device with respect to objects and movements to be detected, since a detectable radiation emitted in the detection zones is imaged to the greatest possible degree onto the sensor elements of the PIR sensor.

According to one exemplary embodiment, the PIR sensor comprises two or four of the sensor elements arranged adjacent to each other.

Conventional PIR sensors with a corresponding number and arrangement of sensor elements can therefore advantageously be used in the motion sensor device.

A lighting system in accordance with a second aspect comprises a motion sensor device in accordance with exemplary embodiments.

Such a lighting system advantageously enables a detection of movements, movement directions, and/or stop locations of objects which move in detection regions of motion sensor devices, for lighting applications, and moreover for an Internet of Things (IoT) which indiscernibly assists a person in his or her activities, for example.

A method in accordance with a third aspect for operating a motion sensor device comprising a PIR sensor having a plurality of sensor elements arranged adjacent to one another, whose active sensor surfaces form a detection area of the PIR sensor, comprises: imaging of a detection region, which comprises detection zones, onto the detection area of said PIR sensor, wherein the detection zones in the detection region of the motion sensor device have a spatially periodic arrangement with direction-dependent periodicity; and a determination of the direction-dependent periodicity of the detection zones in the detection region of the motion sensor device.

According to one exemplary embodiment, the method with the motion sensor device is performed in accordance with exemplary embodiments.

Consequently, the features mentioned in connection with the motion sensor device can be used analogously in the method. Furthermore, analogous effects and advantages result for the method.

