Device and method for generating and evaluating ultrasound signals, particularly for determining the distance of a vehicle from an obstacle
In the device and method for generating and evaluating ultrasound signals, particularly for determining the distance of a vehicle from an obstacle, an ultrasound received signal is received by at least one ultrasound receiver subscriber of a data bus, after a burst transmission signal comprising a plurality of ultrasound pulses and having a burst length has been transmitted by at least one ultrasound transmitter subscriber of the data bus. The ultrasound received signal is subdivided into time sections which are substantially equal to half the burst length. The peak value for each time section of the ultrasound received signal is transmitted via the data bus to a central control and evaluation unit. On the basis of the peak values of the received signal for each time section, taking into account threshold value tracking, it is determined in the control and evaluation unit whether the ultrasound received signal has time sections in which the ultrasound received signal is greater than the tracked threshold value or equal to the tracked threshold value.
1. A device for generating and evaluating ultrasound signals for determining the distance of a vehicle to an obstacle, comprising
a data bus for transmission of useful data and control data be-tween at least one ultrasound transmitter subscriber, at least one ultrasound receiver subscriber and a central control and evaluation unit for controlling the at least one ultrasound transmitter subscriber and the at least one ultrasound receiver subscriber and for evaluation of the received signal of the ultrasound receiver subscriber, performed while tracking a threshold value, under the aspect of whether this received signal at least for a time period is larger than or equal to the tracked threshold value, particularly for obtaining the distance to an obstacle if such an obstacle exist within a distance area of a presettable size,
wherein the ultrasound transmitter subscriber comprises an ultrasonic transmitter for emitting a burst transmission signal which has a burst length and comprises a plurality of ultrasonic pulses, and
wherein the ultrasound receiver subscriber comprises an ultrasonic receiver for receiving, as an ultrasonic received signal, a burst transmission signal reflected at an obstacle, and comprising a signal processing unit for processing the received signal received by the ultrasonic receiver, with the received signal being divided, from the start of an emission of the ultrasound burst transmission signal, into individual time sections of a length substantially equal to half of the burst length,
characterized in:
that the signal processing unit is operative to determine, for each time section, a peak value of the received signal,
that the at least one ultrasound receiver subscriber is operative to transmit the peak values of the time sections of the received signal via the data bus to the central control and evaluation unit, and
that, on the basis of the peak values received from the at least one ultrasound receiver subscriber via the data bus, the control and evaluation unit is operative to detect whether the received signal in at least one of the time sections is larger than or equal to the tracked threshold value.
2. The device according to claim 1 , wherein the signal processing unit of the at least one ultrasound receiver subscriber is operative to detect, for each time section, the average value of the received signal and wherein the at least one ultrasound receiver subscriber is operative to transmit, via the data bus, the average values for each time section to the control and evaluation unit.
3. The device according to claim 1 , wherein the data bus has connected to it a plurality of ultrasound transmitter subscribers and a plurality of ultrasound receiver subscribers.
4. The device according to claim 1 , wherein the at least one ultrasound transmitter subscriber and the at least one ultrasound receiver subscriber or respectively a pair of ultrasound transmitter subscriber and ultrasound receiver subscriber are designed as a common subscriber of the data bus, the ultrasound transmitter and the ultrasound receiver being combined into one unit in the form of an ultrasound transducer.
5. The device according to claim 1 , wherein the data bus has a plurality of ultrasound transmitter subscribers an a plurality of ultrasound receiver subscribers connected to it, the number of the ultrasound transmitter subscribers being larger than the number of ultrasound receiver subscribers.
6. The device according to claim 1 , wherein, on the basis of the peak values and optionally average values for each time section of the received signal of the at least one ultrasound receiver subscriber as received via the data bus, the control and evaluation unit is operative to detect a potential echo and, on the basis of the length of time between the start of the emission of the ultrasound burst transmission signal and the occurrence of the echo, to determine the distance to a potential obstacle.
7. A method for generating and evaluating ultrasound signals, particularly for determining the distance of a vehicle to an obstacle, wherein, in said method
an ultrasound received signal is received by at least one ultrasound receiver subscriber of a data bus after a burst transmission signal having a burst length and comprising a plurality of ultrasonic pulses has been emitted by at least one ultrasound transmitter subscriber of the data bus,
wherein the ultrasound received signal is divided into time sections substantially equal to half of the burst length,
wherein for each time section of the ultrasound received signal, the peak value is transmitted via the data bus to a central control and evaluation unit, and
wherein on the basis of the peak values of the ultrasound received signal for each time section, it is determined in the control and evaluation unit under consideration of a threshold value tracking whether the ultrasound received signal comprises time sections in which the ultrasound received signal is larger than or equal to the tracked threshold value.
8. The method according to claim 7 , wherein the signal processing unit of the at least one ultrasound receiver subscriber is operative to detect, for each time section, the average value of the received signal, and wherein the at least one ultrasound receiver subscriber is operative to transmit, via the data bus, the average values for each time section to the control and evaluation unit.
9. The method according to claim 7 , wherein the data bus has connected to it a plurality of ultrasound transmitter subscribers and a plurality of ultrasound receiver subscribers.
10. The method according to claim 7 , wherein the at least one ultrasound transmitter subscriber and the at least one ultrasound receiver subscriber or respectively a pair of ultrasound transmitter subscriber and ultrasound receiver subscriber are designed as a common subscriber of the data bus, the ultrasound transmitter and the ultrasound receiver being combined into one unit in the form of an ultrasound transducer.
11. The method according to claim 7 , wherein the data bus has a plurality of ultrasound transmitter subscribers and a plurality of ultrasound receiver subscribers connected to it, the number of the ultrasound transmitter subscribers being larger than the number of ultrasound receiver subscribers.
12. The method according to claim 7 , wherein, on the basis of the peak values for each time section of the received signal of the at least one ultrasound receiver subscriber as received via the data bus, the control and evaluation unit is operative to detect a potential echo and, on the basis of the length of time between the start of the emission of the ultrasound burst transmission signal and the occurrence of the echo, to determine the distance to a potential obstacle.