Methods for adjusting ultrasound measurements

Abstract

The present invention relates to a method (100) for adjusting ultrasonic measurement values, comprising the steps: determining (S1) a reference curve based on an orientation (204) of an ultrasonic sensor element (202) which is configured to output at least one ultrasonic measurement value and based on a ground reference, forming (S2) a measurement curve based on the at least one ultrasonic measurement value, forming (S3) a deviation value based on a ratio between the measurement curve and the reference curve for a predetermined period, determining (S4) a threshold function based on the deviation value and the reference curve.

Description

State of the art

[0001] The present invention relates to a method for adapting ultrasonic measurement values, an ultrasonic sensor unit, a computer program, a computer-readable medium, and a vehicle.

[0002] There are currently a variety of different solutions for processing ultrasonic measurement values ​​in the automotive sector. Due to the increasing number of ultrasonic sensors in the automotive sector and the increased demands on evaluation quality, the need for innovative and robust methods for evaluating ultrasonic measurement values ​​is continuously growing.

[0003] The constant weight reduction in the vehicle sector to reduce fuel consumption as well as increasing competition are creating cost pressure, so that cheaper and more efficient components for vehicles are increasing in demand. Disclosure of the invention

[0004] The inventive method for adapting ultrasonic measurement values ​​with the features of claim 1 has the advantage over the known method that the detection sensitivity of ultrasonic sensors can be improved through the adapted threshold calculation. Prior knowledge of the received signal profile can be used to calculate a threshold, thus achieving better adaptation to the underlying surface. This further improves the detection accuracy of ultrasonic sensor elements or ultrasonic sensor units.

[0005] This is achieved according to the invention in that the method for adjusting ultrasonic measurement values ​​comprises the steps: - Determining a reference curve based on an orientation of an ultrasonic sensor element which is configured to output at least one ultrasonic measurement value and based on a ground reference, - Forming a measured value curve based on the at least one ultrasonic measured value, - Forming a deviation value based on a relationship between the measured value curve and based on the reference curve for a predetermined period of time, - Determine a threshold function based on the deviation value and based on the reference curve.

[0006] In other words, a threshold value for ultrasonic measurement values ​​is adaptively determined dynamically or time-dependently in order to thus better evaluate the ultrasonic measurement values. In particular, this can be determined depending on the orientation of the ultrasonic sensor element or an installation direction, as well as a ground reference. For example, a vehicle can have a plurality of ultrasonic sensor elements, wherein a respective orientation exists for each of the different ultrasonic sensor elements, but a predefined background or ground reference is used to form the reference curve. Further preferably, a measurement curve is created or generated and / or formed based on a time profile and the ultrasonic measurement values.Further preferably, the deviation value is calculated based on the integral of the reference curve and the integral of the measured value curve, with the integrals being formed, in particular, over the duration of the predetermined period. Thus, a deviation value, or delta, or similar, can be determined. For example, the integral of the received signal can be divided by the integral of the reference curve at any time within the predetermined period, in order, in particular, to be able to calculate the deviation value relative to the reference curve. Furthermore, a threshold function is determined, which is based, in particular, on the deviation value and the reference curve.

[0007] The subclaims show preferred developments of the invention.

[0008] Further preferably, the method comprises the step: - Determining an output value based on the determined threshold function and based on the at least one ultrasonic measurement value.

[0009] An advantage of this embodiment is that the method can be used to improve the output value of the ultrasonic measurement value, so that a more accurate detection or a higher quality ultrasonic measurement value signal can be output.

[0010] More preferably, the method further comprises the steps: - adjusting the deviation value to form a filtered deviation value, wherein the filtered deviation value is free of values ​​in a predetermined range, - Determine the threshold function based on the filtered deviation value and based on the reference curve.

[0011] An advantage of this embodiment is that by adjusting the deviation value, the stochastic nature of the received signal can be compensated for by filtering or smoothing the deviation value. This further improves the threshold calculation.

[0012] More preferably, the method further comprises the steps: - Receiving and / or selecting a parameter set to set a sensitivity, - Determine the threshold function based on the filtered deviation value, the reference curve and based on the parameter set.

[0013] An advantage of this embodiment is that the sensitivity can be used to react to a particular environmental or application scenario in order to further improve the calculation of the threshold function.

[0014] Preferably, the method further comprises the steps: - Determining a change in the filtered deviation value in the predetermined period, - Comparing the change in the filtered deviation value with the reference curve to determine an echo in the ultrasonic value, - Adjusting the filtered deviation value to eliminate the echo in the filtered deviation value.

[0015] An advantage of this embodiment is that if the change in the filtered deviation values ​​contains jumps, abnormalities, or artifacts, these can be classified as echoes of the ultrasound value and subsequently excluded or eliminated from the filtered deviation value. Thus, the threshold calculation is freed from any echoes in the ultrasound value or ultrasound data set.

[0016] More preferably, the method comprises the steps: - Determining a signal-to-interference ratio in the measured value curve, - Adjusting the threshold function when the signal to the interference ratio exceeds a predetermined limit.

[0017] An advantage of this embodiment is that high sensor noise caused by external acoustic sources or electromagnetic interference can be subtracted from the measured value curve, thus further improving the model prediction using the threshold value. For example, a signal-to-interference ratio can be determined at the beginning and / or a signal-to-noise ratio can be adopted from a previous measurement.

[0018] More preferably, the method further comprises the steps: - Detecting and / or selecting an environmental parameter of the ultrasonic sensor element, - Adjust the reference curve based on the environmental parameter.

[0019] An advantage of this embodiment is that the calculation of the threshold function can take into account any environmental parameters, such as air temperature and humidity, or similar factors that may influence the airborne sound absorption of the ultrasonic signal. This further increases the stability of the threshold calculation.

[0020] More preferably, the method further comprises the step: - Initiating the deviation value based on an initiation value, wherein the initiation value is a measured value outside the predetermined period and / or the initiation value is a historical value of a previous measurement.

[0021] An advantage of this embodiment is that the calculation of the threshold function is shortened, since the integration time of the correction factor is shortened by initiating the deviation value using an initiation value. Thus, a previous measurement or a predetermined value can be used to guide the deviation value onto the correct path.

[0022] More preferably, the predetermined period of time has a first limit value and a second limit value, the method further comprising the step of: - Adjusting the predetermined period for a time range between the first limit value and the second limit value.

[0023] An advantage of this embodiment is that the predetermined period in which the received signal or the measured value curve and the reference curve are integrated can be continuously adjusted. For example, an evaluation window is defined as a predetermined period of time that has a value to the left and a value to the right of a currently observed point in time, which can, for example, be up to + / -6 ms. Thus, the integral of the measured value curve and the reference curve can be formed over this period in order to determine the deviation value.

[0024] More preferably, the predetermined period of time has a reference and a third limit value, the method further comprising a step: - Forming the predetermined period between the reference and the third limit value.

[0025] An advantage of this embodiment is that the predetermined time period can be significantly increased, since the predetermined time period is a continuously growing window. Thus, the measured value curve and the reference curve can be integrated between a starting point and a current time range plus a delta, such as one millisecond, in order to calculate the deviation value.

[0026] A further aspect of the invention relates to an ultrasonic sensor unit which is configured to detect at least one ultrasonic measurement value and is configured to carry out steps of the method as described above and below.

[0027] A further aspect of the invention relates to a computer program which is designed to carry out steps of the method as described above and below.

[0028] Another aspect of the invention relates to a computer-readable medium storing the computer program as described above and below.

[0029] A further aspect of the invention relates to a vehicle which has the ultrasonic sensor unit as described above and below and / or is configured to carry out steps of the method as described above and below. Short description of the drawings

[0030] Embodiments of the invention are described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 and Fig. 2 a flowchart illustrating steps of the method according to an embodiment, Fig. 3 an ultrasonic sensor unit, Fig. 4 a vehicle, Fig. 5 a diagram illustrating the method according to an embodiment. Embodiments of the invention

[0031] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0032] Fig. Figure 1 shows a flowchart illustrating steps of the method 100 according to one embodiment. The method 100 for adjusting ultrasonic measurement values ​​preferably comprises the following steps: - Determining S1 a reference curve based on an orientation 204 of an ultrasonic sensor element 202, which is configured to output at least one ultrasonic measurement value and based on a ground reference, - Forming S2 a measured value curve based on the at least one ultrasonic measured value, - Forming S3 a deviation value based on a relationship between the measured value curve and the reference curve for a predetermined period of time, - Determining S4 a threshold function based on the deviation value and based on the reference curve,

[0033] Fig. 2 shows a flowchart illustrating steps of the method 100 according to one embodiment. The method 100 in Fig. 2 has the same steps S1 to S4 as already described with regard to the Fig. 1. Further preferably, the method 100 comprises the step of determining S6 an output value. Preferably, the method 100 comprises the step of adjusting S7 the deviation value and determining S8 the threshold function. Furthermore, the method 100 preferably comprises the steps of receiving and / or selecting S9 a parameter set and determining S10 the threshold function.

[0034] Further preferably, the method 100 comprises the steps of determining S11 a change, comparing S12 the change, and adjusting S13 the filtered deviation value. The method 100 preferably includes the steps of determining S14 a signal and adjusting S15 the threshold function. Furthermore, the method 100 preferably includes the steps of detecting and / or selecting S16 and adjusting S17. The method 100 preferably includes the step of initiating S18 the deviation value.

[0035] Further preferably, the method 100 comprises the step of adapting S19. Preferably, the method 100 comprises the step of forming S20.

[0036] Fig. 3 shows a sensor unit 200 according to one embodiment. The ultrasonic sensor unit 200 is configured to detect at least one ultrasonic measurement value. Further preferably, the ultrasonic sensor unit 200 comprises an ultrasonic sensor element 202 configured to output an ultrasonic measurement value. Further preferably, the ultrasonic sensor element 202 is arranged in a predefined orientation 204, which is known to the ultrasonic sensor unit 200. Further preferably, the sensor unit 200 is configured to perform steps of the method 100 as above and below.

[0037] Fig. 4 shows a vehicle 400 according to one embodiment. The vehicle 400 is configured to perform steps of the method 100, as described above and below. More preferably, the vehicle 400 comprises an ultrasonic sensor unit 200, as described above and below. Furthermore, the vehicle 400 preferably comprises a computer-readable storage medium 300 that stores the computer program, as described above and below.

[0038] Fig.5 shows a diagram 500 according to an embodiment for illustrating the method 100. The diagram 500 has a first axis 502, which represents measured values. More preferably, the diagram 500 has a second axis 504, which represents the time course. More preferably, a data curve or reference curve 506 is depicted in the diagram 500. Furthermore, a measured value curve 508 is preferably depicted in the diagram 500. Based on the relationship between the reference curve 506 and the measured value curve 508, a threshold function 510 can be determined.

Claims

[1] A method (100) for adjusting ultrasonic measurement values, comprising the steps of: - determining (S1) a reference curve based on an orientation (204) of an ultrasonic sensor element (202) which is configured to output at least one ultrasonic measurement value, and based on a ground reference, - forming (S2) a measured value curve based on the at least one ultrasonic measured value, - forming (S3) a deviation value based on a relationship between the measurement curve and the reference curve for a predetermined period of time, - Determining (S4) a threshold function based on the deviation value and the reference curve. [2] The method (100) of claim 1, further comprising the steps of: - Determining (S6) an output value based on the determined threshold function and based on the at least one ultrasonic measurement value. [3] Method (100) according to one of the preceding claims, further comprising the steps: - adjusting (S7) the deviation value to form a filtered deviation value, wherein the filtered deviation value is free of values in a predetermined range, - Determining (S8) the threshold function based on the filtered deviation value and based on the reference curve. [4] The method (100) of claim 3, further comprising the steps of: - Receiving and / or selecting (S9) a parameter set for setting a sensitivity, - Determining (S10) the threshold function based on the filtered deviation value, the reference curve and based on the parameter set. [5] Method (100) according to one of claims 3 to 4, further comprising the steps: - determining (S11) a change in the filtered deviation value in the predetermined period, - comparing (S12) the change in the filtered deviation value with the reference curve to determine an echo in the ultrasonic value, - Adjusting (S13) the filtered deviation value to eliminate the echo in the filtered deviation value. [6] Method (100) according to one of the preceding claims, further comprising the steps: - Determining (S14) a signal-to-interference ratio in the measured value curve, - Adjusting (S15) the threshold function when the signal-to-interference ratio exceeds a predetermined limit. [7] Method (100) according to one of the preceding claims, further comprising the steps: - detecting and / or selecting (S16) an environmental parameter of the ultrasonic sensor element (202), - Adjust (S17) the reference curve based on the environmental parameter. [8] Method (100) according to one of the preceding claims, further comprising the step: - initiating (S18) the deviation value based on an initiation value, wherein the initiation value is a measured value outside the predetermined period and / or the initiation value is a historical value of a previous measurement. [9] The method (100) according to any one of the preceding claims, wherein the predetermined period of time has a first threshold value and a second threshold value, further comprising the step: - adjusting (S19) the predetermined period of time for a time range between the first limit value and the second limit value. [10] The method (100) of any one of claims 1 to 8, wherein the predetermined period of time comprises a reference and a third limit value, further comprising the step: - forming (S20) the predetermined period between the reference and the third limit value. [11] Ultrasonic sensor unit (200) which is configured to detect at least one ultrasonic measurement value and is configured to carry out steps of the method according to one of claims 1 to 10. [12] Computer program adapted to carry out steps of the method according to any one of claims 1 to 10. [13] A computer-readable storage medium on which the computer program according to claim 12 is stored. [14] Vehicle (400) comprising an ultrasonic sensor unit (200) according to claim 1 and / or being configured to carry out the method according to one of claims 1 to 10.

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