Abstract:
A method for checking a surroundings sensor device including the following: transmitting a reference sound signal by a reference sound source; detecting the reference sound signal by a receiving device of the surroundings sensor device; and calibrating the surroundings sensor device by a computer unit of the surroundings sensor device based on the detected reference sound signal for checking the surroundings sensor device.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a method for checking a surroundings sensor device, a reference sound source, and a corresponding surroundings sensor device. 
       BACKGROUND INFORMATION 
       [0002]    German patent document DE 40 235 38 A1 refers to a collision warning device, in particular for avoiding collisions with stationary obstacles in the vicinity of a motor vehicle, having a device for contactless distance measurement, at least two ultrasonic sensors being situated at a predefined spacing for the collision warning device. 
         [0003]    In the device described there, an evaluation is provided for the transit times between the transmission of each ultrasonic signal and the reception of a reflected ultrasonic signal, the ultrasonic signal of the same and the other ultrasonic sensor being respectively used. 
         [0004]    The publication entitled “Fast Bearing Measurement with a Single Ultrasonic Transducer” by T. Yata, L. Kleeman, and S. Yuta, appearing in the International Journal of Robotics Research, Volume 17, Number 11 on pages 1202-1213 published in 1998, describes a method and a device for ultrasonic scanning. In the method discussed there, a single ultrasonic transducer, which is operated in an ultrasonic pulse-echo detection mode, is used to extract information. 
         [0005]    Patent document FR 281 797 3 A1 discusses a method for detecting the position of objects for assistance during parking of a motor vehicle, the method being carried out using a network of ultrasonic sensors on the motor vehicle. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention creates a method for checking a surroundings sensor device as described herein, a reference sound source for transmitting a reference sound signal having the features described herein, and a surroundings sensor device as described herein. 
         [0007]    The idea of the present invention is that a system monitoring and calibration may be carried out for the surroundings sensor device by using a reference sound source or a reference backscatter body. 
         [0008]    In comparison to a self-diagnosis, which supplies electrical signals, the entire system may be included in the system monitoring and calibration. Using the sonic measurement, all receiving transducers may be checked and calibrated, including the amplifier and analog-digital converter channels of the transmission and/or receiving device. 
         [0009]    Advantageous specific embodiments and refinements arise from the further descriptions herein and also from the description with reference to the figures. 
         [0010]    According to one specific embodiment of the present invention, the calibration of the surroundings sensor device includes a calibration of the receiving device of the surroundings sensor device. This enables a simple and safe check of the receiving device. 
         [0011]    According to one specific embodiment of the present invention, the calibration of the surroundings sensor device includes a calibration of the computer unit of the surroundings sensor device. This enables a simple and safe check of the computer unit. 
         [0012]    According to one specific embodiment of the present invention, the calibration of the surroundings sensor device includes a detection of the position of the reference sound source. Thus, the function of the surroundings sensor device may be checked directly. 
         [0013]    According to one specific embodiment of the present invention, a backscatter body is used as the reference sound source and a sound signal is transmitted from a transmission device of the surroundings sensor device to the reference sound source. The use of a reference backscatter body has the advantage over a reference sound source that it is an inexpensive and simple passive body, and also that the sound transmitter of the surroundings sensor device is included in the check. 
         [0014]    According to one specific embodiment of the present invention, a harmonic sound signal, a burst signal, a sweep signal, or a pulse signal is used as the reference sound signal. 
         [0015]    According to one specific embodiment of the present invention, a plurality of reference sound signals with different characteristics and/or in chronological sequence is used. 
         [0016]    The embodiments and refinements described may be arbitrarily combined with each other. 
         [0017]    Additional possible embodiments, refinements, and implementations of the present invention also include combinations not explicitly listed of features of the present invention described previously or subsequently with regard to the exemplary embodiments. 
         [0018]    The accompanying drawings should convey a further understanding of the specific embodiments of the present invention. They illustrate specific embodiments and serve for the explanation of principles and concepts of the present invention in conjunction with the description. 
         [0019]    Other specific embodiments and many of the advantages listed arise with regard to the drawings. The elements of the drawings represented are not necessarily shown to scale with each other. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  shows a schematic representation of a surroundings sensor device according to one specific embodiment of the present invention. 
           [0021]      FIG. 2  shows a schematic representation of a flow chart of a method for checking a surroundings sensor device according to yet another specific embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    In the figures of the drawing, the same reference numerals designate identical or functionally identical elements, components, or method steps, insofar as nothing is indicated to the contrary. 
         [0023]      FIG. 1  shows a schematic representation of a surroundings sensor device according to one specific embodiment of the present invention. 
         [0024]    Surroundings sensor device  100  includes a memory device  10 , a receiving device  20 , a transmission device  30 , and a computer unit  40 . 
         [0025]    Receiving device  20  is configured to detect reference sound signal RSS transmitted by reference sound source RQ. Transmission device  30  is configured, for example, to convert electrical signals from computer unit  40  into sound and to transmit them. 
         [0026]    Memory device  10  is configured to provide operating data to surroundings sensor device  100 . The operating data may thereby include data regarding the most recently carried out calibration or check of surroundings sensor device  100 . In addition, the operating data stored in memory device  10  may also include data regarding a position of reference sound source RQ to be determined during calibration of surroundings sensor device  100 . 
         [0027]    Computer unit  40  is configured to calibrate surroundings sensor device  100  using the detected reference sound signal RSS, and thereby check it. 
         [0028]    Receiving device  20 , memory device  10 , and computer unit  40  are, for example, implemented as network-connected computer units. 
         [0029]    Computer unit  40  and memory device  10  are, for example, configured as one processor unit or as another electronic data processing unit. 
         [0030]    Display device  50  of surroundings sensor device  100  is, for example, coupled to computer unit  40  and is provided for displaying the function of surroundings sensor device  100 . 
         [0031]    Display device  50  may be configured as a liquid crystal display or as a liquid crystal monitor, the function of which is based on the fact that liquid crystals influence the polarization direction of light when a certain level of electrical voltage is applied. 
         [0032]    Receiving device  20  is, for example, configured as a microphone or as a piezoelectric sound transducer, or as another sound transducer, which converts airborne sound as sound pressure oscillations into corresponding electrical voltage variations as a microphone signal. 
         [0033]    Transmission device  30  is, for example, configured as an electrodynamic loudspeaker with a central drive or as a piezoelectric sound transducer or as an electrostatic loudspeaker or as a ferroelectric loudspeaker or as an electromagnetic loudspeaker or as another loudspeaker. 
         [0034]    Computer unit  40  is configured for example as a microcontroller, also known as a μcontroller, which, in addition to a processor, also combines units for peripheral functions on one chip. 
         [0035]    Surroundings sensor device  100  may determine the distance of a reflection point P 1  to object O using a transit time of the sound pulse measured by computer unit  40 . 
         [0036]    Optionally, the localization of reflection point P 1  of object O may be carried out by surroundings sensor device  100  via a method based on a frequency shift or on a trilateration, the direction and the complete spatial coordinates of reflection point P 1  being determined with the aid of multiple spatially separated receiving devices  20  and/or multiple spatially separated transmission devices  30 . 
         [0037]    The maximum transit time of a sound pulse in the surroundings is referred to as the burst transit time of surroundings sensor device  100  and determines the maximum range for object detection by surroundings sensor device  100 . 
         [0038]    Reference sound source RQ or the backscatter body may be easily integrated into the base or charging station of a robot having surroundings sensor device  100 . The backscatter body may have a solid material, such as metal or plastic, and be configured with a defined geometry, such as a spherical or cylindrical shape or as a triple reflector. Ultrasonic-based surroundings sensor device  100  thereby uses the integrated transmission device  30  to spotlight the backscatter body. 
         [0039]    If reference sound source RQ or the backscatter body is positioned too close to the surroundings sensor device for a system monitoring and calibration, the robot equipped with surroundings sensor device  100  may travel a defined path in order to distance itself from the base or charging station. 
         [0040]    Surroundings sensor device  100  and reference sound source RQ are suitable for ultrasonic-based applications, which process directional information and use array systems, such as a surroundings sensing for robots, also for autonomously functioning lawn mowers, vacuums, transport robots, or other moving robots. 
         [0041]      FIG. 2  shows a schematic representation of a flow chart of a method for checking a surroundings sensor device according to yet another specific embodiment of the present invention. 
         [0042]    As a first method step, transmission S 1  of a reference sound signal RSS is carried out by reference sound source RQ. 
         [0043]    Reference sound signal RSS may be configured as a limited number of oscillations at a fixed frequency with a certain duration. Reference sound signal RSS may likewise be configured as a harmonic sound signal, a burst signal, a sweep, signal, or a pulse signal. A periodic signal may be used here as a sweep signal, which changes its frequency from an initial value to an end value within a defined time period. 
         [0044]    As a second method step, detection S 2  of reference sound signal RSS is carried out by a receiving device  20  of surroundings sensor device  100 . 
         [0045]    As a third method step, calibration S 3  of surroundings sensor device  100  is carried out by computer unit  40  of surroundings sensor device  100  using the detected reference sound signal RSS for checking surroundings sensor device  100 . 
         [0046]    The individual method steps of the method for checking a surroundings sensor device may be repeated arbitrarily, for example iteratively or recursively. 
         [0047]    Although the present invention has been described above based on exemplary embodiments, it is not limited thereto, but instead is modifiable in multiple ways. In particular, the present invention may be altered or modified in manifold ways without deviating from the core of the present invention.