Sensor with monolithic ultrasonic array

A method for determining environmental factors at a bottom side of a sensor via its reference measurement path, the sensor comprising:

• a housing, on a bottom side of which is arranged a flat elongated ultrasonic transducer array arranged on a bottom side of the housing, the ultrasonic transducer comprising multiple measurement ultrasonic transducers that are oriented with their sound-radiating transducer surfaces parallel to the ultrasonic transducer array;
• an electronic analysis device that provides measured values for the position of the guide surface as a function of measurement signals of the measurement ultrasonic transducers;
• a reference ultrasonic transducer being attached to each of two outer ends of the ultrasonic transducer array and oriented with their sound-radiating transducer surfaces parallel to the ultrasonic transducer array;
• at least two reflector surfaces attached at a distance from the bottom side and in alignment with the reference ultrasonic transducers, the reflector surfaces being inclined at an angle of 45° to the applicable reference ultrasonic transducer and face one another, and thereby a reference measurement path with a known length between the two reference ultrasonic transducers is formed;
• a single, flat, elongated acoustic matching layer, connecting the reference ultrasonic transducers and the measurement ultrasonic transducers of the ultrasonic transducer array;
• multiple flat, rectangular measurement piezo plates, spaced apart from one another, applied to the back of the single, flat, elongated acoustic matching layer;
• and
• a circular reference piezo plate applied to each of the two outer ends of the single, flat, elongated acoustic matching layer, wherein the method comprises:
• deflecting by the two reflector surfaces a short acoustic pulse with a first ultrasonic frequency emitted by one of the reference ultrasonic transducers,
• receiving by the other reference ultrasonic transducer the short acoustic pulse that travels over the reference measurement path;
• measuring via the analysis device a first time between the emission of the acoustic pulse and its reception;
• repeating the same measurement in an opposite direction, such that the analysis device measures a second time;
• and
• computing the arithmetic mean from the first and second measured times, and the mean value serving as a measure for the current values of the environmental factors at the bottom side of the sensor.

A method for determining a position of a sensor relative to a guide surface, the method comprising:

• emitting transmit pulses with a second ultrasonic frequency by measurement ultrasonic transducers;
• and
• receiving reflections of the transmit pulses at a guide surface as an echo;
• measuring transit times of the echoes;
• and
• producing positional information from the measured transit times in the analysis device through trigonometric calculations and outputting such as measured values;
• wherein current values of environmental factors in the reference measurement path are calculated using a method for determining environmental factors at a bottom side of the sensor via its reference measurement path to compensate for environmental influences in the calculation of the positional information, the method comprising:
• deflecting by the two reflector surfaces a short acoustic pulse with a first ultrasonic frequency emitted by one of the reference ultrasonic transducers,
• receiving by the other reference ultrasonic transducer the short acoustic pulse that travels over the reference measurement path;
• measuring via the analysis device a first time between the emission of the acoustic pulse and its reception;
• repeating the same measurement in an opposite direction, such that the analysis device measures a second time;
• and
• computing the arithmetic mean from the first and second measured times, and the mean value serving as a measure for the current values of the environmental factors at the bottom side of the sensor,
• wherein the sensor comprises:
• a housing, on a bottom side of which is arranged a flat elongated ultrasonic transducer array arranged on a bottom side of the housing, the ultrasonic transducer comprising multiple measurement ultrasonic transducers that are oriented with their sound-radiating transducer surfaces parallel to the ultrasonic transducer array;
• an electronic analysis device that provides measured values for the position of the guide surface as a function of measurement signals of the measurement ultrasonic transducers;
• a reference ultrasonic transducer being attached to each of two outer ends of the ultrasonic transducer array and oriented with their sound-radiating transducer surfaces parallel to the ultrasonic transducer array;
• at least two reflector surfaces attached at a distance from the bottom side and in alignment with the reference ultrasonic transducers, the reflector surfaces being inclined at an angle of 45° to the applicable reference ultrasonic transducer and face one another, and thereby a reference measurement path with a known length between the two reference ultrasonic transducers is formed;
• a single, flat, elongated acoustic matching layer, connecting the reference ultrasonic transducers and the measurement ultrasonic transducers of the ultrasonic transducer array;
• multiple flat, rectangular measurement piezo plates, spaced apart from one another, applied to the back of the single, flat, elongated acoustic matching layer;
• and
• a circular reference piezo plate applied to each of the two outer ends of the single, flat, elongated acoustic matching layer.

A sensor for detecting a position relative to a guide surface, the sensor comprising:

• a housing;
• a single, flat, elongated acoustic matching layer arranged flush against a bottom of the housing;
• a first circular reference piezo plate disposed at a first end of the matching layer and a second circular reference piezo plate disposed at a second end of the matching layer;
• a plurality of flat rectangular measurement piezo plates arranged on the matching layer between the first circular reference piezo plate and the second circular reference piezo plate;
• an electronic analysis device that provides measured values for a position of the guide surface as a function of measurement signals of the plurality of rectangular measurement piezo plates;
• and
• at least two reflector surfaces attached at a distance from the bottom of the housing and in alignment with the first circular reference piezo plate and the second circular reference piezo plate, the reflector surfaces being inclined at an angle of 45° to the first circular reference piezo plate and the second circular reference piezo plate and facing one another.