DE19860901A1 - Device for determining situation and/or movement of surface of liquid situated in container in vehicle has A/D converter, processor, and memory to calculate rotation of liquid surface determined from recorded distance values - Google Patents

Abstract

A sensor (1) acquires data such as distance values, which describe a distance of a liquid surface from the sensor and several areas. An A/D converter (2), processor (3), and memory (4) are used to calculate a rotation value, which describes the rotation to the liquid surface determined from the recorded distance values. An Independent claim is included for a method for determining the situation and/or movement of a surface of a liquid situated in a container

Description

State of the art

The invention relates to an apparatus and a method to determine the position and / or movement of a Surface of a liquid in a container that is located in a vehicle in particular is. Corresponding devices and methods are from the State of the art in many modifications known.

From the publication "Soviet Inventions Illustrated, Section R: Electrical, Measuring, Testing ", page 20, Week B02, SU-593-148; 1979, is a device for investigation the rotational speed of a container is known. Here a metal plate protrudes into this container, the forms a condenser together with the container. By the rotation of the container deforms the surface a liquid contained in the container, whereby the capacitance of the capacitor changed. The capacity of the Capacitor is therefore a measure of that Speed of rotation of the container. At this The disadvantage of the device is that it is carried out with it Measurement over the entire surface of the in the container contained liquid forming an average over  the entire liquid surface corresponds. The Detection of several individual, i.e. H. more discreet Distance sizes, the distance between the sensor and different areas of the liquid surface describe is not possible with this device. This makes the acquisition of accurate or fine Surface structures of the liquid are not possible.

The object of the invention is an improved device or an improved method for determining the situation and / or the movement of a surface of a liquid, the in a container, which is particularly in a Vehicle is located, is included to create.

This object is achieved by the features of claim 1 and solved by that of claim 10.

Advantages of the invention

The device for determining the position and / or Movement of a surface of a liquid contained in a Container, which is in particular in a vehicle is included, has sensor means by means of which Distance quantities, the distance between the sensor means and several areas of the liquid surface describe, be recorded. The device also contains Evaluation means by means of which from the recorded Distance quantities at least one rotational movement quantity that the Describes the rotational movement of the liquid surface is determined.

By determining distance sizes that the distance between the sensor means and several areas of the Describing the liquid surface is essential more precise statement about the position and / or the movement of the Liquid surface possible. For example  individual structures recognized in the liquid surface that are characteristic of a rotational movement, and on the basis of which the rotational movement quantity is determined can.

In addition to determining the amount of rotary motion advantageously by means of the evaluation means from the distance sizes also recorded a location size, the location describes the surface of the liquid. Consequently is next to the information about a rotary movement of the Liquid surface also information about the location the liquid surface.

Depending on the location size, a first size which determines the current vehicle acceleration and / or vehicle inclination. Complementary or alternatively, depending on the amount of rotary motion second size is determined, which is the current Vehicle rotation describes. That is, out of position and / or the movement of the liquid surface can be of sizes can be determined, the vehicle movement or the Describe the vehicle position. The advantage here is that for the determination of these variables no additional sensors is required. For one thing, this leads to one Cost savings and secondly, this brings a profit Operational safety because less for a vehicle Sensors are required, which may fail.

The distance sizes are advantageously by Ultrasonic measurement and / or by microwave measurement, in particular radar measurement, and / or by optical measurement detected. With an ultrasound measurement or a Microwave measurement is advantageous when Sensor means to use a single transducer that is under emits at least three main directions. That is, as Sensor means a single sensor is used with the  the distance between it and the surface of the liquid is recorded three-dimensionally. By using a single converter reduces the effort Walkers. On the other hand, the adjustment of the Sensor means, since only one converter has to be adjusted. The Consequently, an ultrasonic sensor or a sensor Be a radar sensor. Instead of one converter, you can alternatively three transducers can be used, each in radiate essentially under one main direction. Is in this case, the expenditure on converters and the Adjustment effort is greater, however, in this case conventional, i.e. H. less elaborate and possibly cheaper converters can be used.

In the case of an optical measurement, a is used as the sensor means optical receiver, especially an optical one Reception area used. From the state of the Technology known CCD sensors are used.

Alternatively, you can use a video sensor, especially the use of a small video camera. On the optical receiver becomes part of the Liquid surface depicted.

Advantageously, the evaluation means in Dependence of the determined rotational movement quantity and / or Location size and the known dimensions of the container Quantity value for the liquid in the container determined. By doing this, the quantity value can be determined precisely. The for the determination of the The dimensions of the container required in terms of quantity thereby in a memory that is in the evaluation means is included, saved.

The evaluation means also contain the following other components: a microprocessor, with its help the rotational movement size and / or the position size is determined  becomes. An analog / digital converter, with which the of the Signals detected by sensor means are implemented, i. H. be digitized. The analog / digital converter is that Upstream microprocessor, so the Sensor signals are processed in the microprocessor. A Filter device, in particular a low-pass filter, with the at least the distance values detected by the sensor means be filtered.

In addition to the distance values recorded, the determined rotational movement quantity and / or the determined Layer size can be filtered over time. This will make the due to brief vehicle movement and / or Vehicle acceleration onto the liquid surface exerted influences, d. H. the fluctuations of the Liquid surface, especially sloshing movements, eliminated.

As an alternative to the filtering described above the following procedure: are in the vehicle additional sensor means are provided with which sizes, such as the wheel speeds, the steering angle, the Vehicle accelerations in the vehicle's longitudinal direction or in Vehicle transverse direction or the yaw rate can be detected. In the evaluation means is dependent on these quantities at least one vehicle movement quantity that the Vehicle movement describes, determined. Dependent on this vehicle movement quantity and the determined Rotational movement size and / or position size is one of Vehicle movements adjusted quantity value for the in Any liquid present in the container is determined. This Procedure is useful if the vehicle is already with the corresponding sensors.

A major advantage of the device according to the invention is that the concept of the invention  the detection of distance sizes, the distance between the sensor means and several areas of Describe liquid surface, vehicle movement data without additional vehicle motion sensors, such as for example acceleration and / or Rotational motion sensors, have it calculated. Hence are such additional vehicle motion sensors are unnecessary. This makes for example vehicle control systems cheaper. Furthermore, the sensor reliability improved since only one sensor instead of several sensors is necessary. In this case, however, can be viewed an adjusted quantity value for the existing in the container Liquid the above and for filtering alternative approach is not used.

With the help of the device according to the invention or The inventive method can, as by the shown above, a Vehicle acceleration and / or vehicle inclination or one Determine vehicle rotation. You can also use the device according to the invention a quantity value for the Determine the liquid present in the container.

drawing

Fig. 1 is a schematic diagram for explaining the method according to the invention and the basic function of the apparatus which performs the method, and

FIG. 2 also shows schematically and in block diagram form an embodiment of an apparatus that carries out the method.

Embodiment

Referring to FIG. 1 of a liquid container 11 sensor means 1 exemplified as a cube are mounted on the floor. With the help of these sensor means, distance variables are described which describe the distance between the sensor means and several areas of the liquid surface. In other words, the sensor means are mounted in the tank so that the sensor means 1, the current distances a liquid surface A in the tank based on the location O of the sensor means 1 can detect in three dimensions.

The distance variables are detected by ultrasound measurement and / or by microwave measurement, in particular radar measurement, and / or by optical measurement. Thus, for example, an ultrasonic sensor, a radar sensor or a video sensor can be used as sensor means 11 .

The container is one, for example Tank, an oil pan, a transmission oil tank, one Brake fluid reservoir, etc. of a motor vehicle.

Of course, the cubic shape of the container in Fig. 1 is only an example. In the same way, a liquid surface can be detected in a cylindrical, spherical, etc. container. The dimensions W, H, L correspond to the width, the height and the length of the container 11 and are stored in a memory, as will be explained below with reference to FIG. 2.

In the case of an ultrasonic measurement or a microwave measurement, a single transducer or sensor is used as the sensor means 11 , which emits under at least three main directions. That is, the sensor means 11 is designed so that it simultaneously detects the liquid surface A by three "lobes" illustrated by the arrows a, b and c. Alternatively, a sensor means can also be used, which emits under a main direction and with which the liquid surface A is scanned by temporally successive pulses in the three spatial coordinates x, y and z lying along the container edges B, H, L. This procedure is not shown in Fig. 1. In both alternatives, a single sensor is used as the sensor means, with which the distance between it and the liquid surface is detected three-dimensionally.

In the case of ultrasound measurement or microwave measurement, a further alternative is to use at least three transducers, each of which radiates essentially under one main direction. The surface of the liquid can thus also be detected using geometric relationships. A corresponding representation of three or more transducers in FIG. 1 has been omitted.

In the case of an optical measurement, a is used as the sensor means optical receiver, especially an optical one Receiving surface or a video sensor, used on the one Part of the liquid surface is mapped.

As an alternative to the attachment of the sensor means 11 shown in FIG. 1 to the bottom of the container 11 , the sensor means can also be attached to the ceiling of the container, for example. Furthermore, attachment to a side wall of the container is also conceivable if the sensor means have an appropriate radiation characteristic.

According to the invention, the detected distance variables at least one rotational movement quantity, which is the rotational movement describes the surface of the liquid. For this are, for example, in successive time steps the distance variables mentioned above are determined and in one so-called circular or ring memory filed. The for the successive time steps determined  Distance sizes represent "snapshots" of the Fluid surface for these time steps. Because the Liquid surface usually has a structure shows the temporal movement of a section this structure from that for the successive Time steps recorded "snapshots" can be determined. For this purpose, it can be determined, for example, how far a local maximum in the liquid surface during two successive time steps. The so determined rotational movement size contains information about the direction of rotation and / or the speed at which the liquid surface turns and / or about the shape of the Liquid surface.

Furthermore, a position size is determined from the detected distance sizes, which describes the position of the liquid surface, determined. The location size can be using geometric relationships from the determined Distance sizes can be determined.

Depending on the location size, a first size is determined telt, the current vehicle acceleration and / or Describes vehicle inclination. In this determination, the Location size, which be the location of the liquid surface writes, transformed into the first size. In this trans formation, the relationships between the location of the Liquid surface and the inclination or acceleration of the vehicle. For example, the location of the container, the geometry of the vehicle and the container ters and the inertia of the vehicle are taken into account.

Alternatively or in addition to the first size, Ab dependency on the amount of rotary motion that describes the current vehicle rotation. The conversion of the rotary motion quantity into the second quantity is done in the same way as for the first size.  

Furthermore, according to the invention, depending on the determined Rotational movement size and / or position size and the known Dimensions of the container a quantity value for the im Liquid present in the container is determined.

The influence of vehicle movements and / or vehicle accelerations can

• a) by means of temporal filtering, with the recorded Distance sizes and / or the determined location size and / or the determined rotational movement quantity is filtered will, and / or
• b) by determining at least one Vehicle movement quantity, which is the vehicle movement describes, and those from other signals, such as for example the wheel speeds, the Steering angle, vehicle accelerations or the Yaw rate is determined

be eliminated.

The method steps described above can, for example, as will be explained below with reference to FIG. 2, be carried out in succession or essentially simultaneously with a processing device equipped with a program-controlled microprocessor.

In the form of a schematic block diagram shown the device of the invention attached to the bottom of the container 11 sensor means 1 are connected via an analog / digital converter 2, with said processing means. 3 The processing device 3 is in turn connected to a memory 4 which stores at least the dimensions W, H, L of the container 11 . In addition, this memory takes over the function of the ring memory described above. The processing device 3 can receive signals 6 , 7 from further sensors in or on the vehicle, e.g. B. wheel speed signals, steering angle signals, acceleration signals, yaw rate signals, etc.

The analog / digital converter 2 , the memory 4 and the processing device 3 are collectively referred to as the evaluation means.

The filter device mentioned above is contained in the processing device 3 .

The processing device 3 outputs the result signals determined or calculated by it to an output port 5 . A display device for displaying the result signals and / or processing devices of other systems, in particular systems for regulating at least one variable describing the vehicle movement, can be connected there. For such control systems, the first or the second quantity can be used as actual values.

In the case of the determined or calculated result signals or quantities are the rotational movement size and / or the position size and / or the first size and / or the second size and / or the Quantity value for the liquid in the container and / or around the adjusted quantity value.

To FIG. 2, it should be mentioned that two liquid surfaces are shown in it. A denotes a liquid surface that is present, for example, for an inclined or accelerated vehicle. A ', on the other hand, denotes a liquid surface that is available for a vehicle that is rotating.

The invention enables an improved Fill quantity display, and that through a complex, for suitable sensor concept and additionally the calculation of vehicle movement data the three-dimensional distance values of the sensor. Thereby special other vehicle motion sensors for avoid acceleration, rotation, etc.

Furthermore, the reliability of the sensors is improved, there is only one sensor instead of several Sensors is necessary.

In addition, it should be noted that the invention Device and the method according to the invention not only for vehicles but for all kinds of Means of transportation is applicable.

Claims (16)

1. Device for determining the position and / or the movement of a surface of a liquid contained in a container ( 11 ), which is located in particular in a vehicle,
the sensor means ( 1 ) contains, by means of which distance variables, which describe the distance between the sensor means and several loading areas of the liquid surface, who the detected, and
which contains evaluation means ( 2 , 3 , 4 ) by means of which at least one rotational movement quantity, which describes the rotational movement of the liquid surface, is determined from the detected distance quantities. 2. Device according to claim 1, characterized in that that by means of the evaluation means from the detected distance sizes also a location size, which is the location of the liquid surface describes, is determined. 3. Device according to claim 1 or 2, characterized net, that depending on the size of the location a first size is the current vehicle acceleration and / or vehicle inclination describes, and / or that depending on the amount of rotation, a second Size is determined which is the current Vehicle rotation describes.   4. The device according to claim 1, characterized in that the distance sizes by ultrasonic measurement and / or by microwave measurement, in particular radar measurement, and / or can be detected by optical measurement. 5. The device according to claim 4, characterized in
that in the case of an ultrasonic measurement or a microwave measurement, a single transducer is used as the sensor means, which radiates under at least three main directions, or that at least three transducers are used, each of which radiates essentially under one main direction, or
that in the case of an optical measurement, an optical receiver, in particular an optical receiving surface or a video sensor, is used as sensor means, onto which a part of the liquid surface is imaged. 6. The device according to claim 1, characterized in that a single sensor is used as the sensor means, with which the distance between him and the Liquid surface is recorded three-dimensionally. 7. The device according to claim 1 or 2, characterized in that a quantity value for the liquid present in the container is determined with the aid of the evaluation means as a function of the determined rotational movement size and / or position size and the known dimensions of the container, in particular for this purpose the evaluation means contain a memory ( 4 ) in which at least the dimensions of the container are stored. 8. The device according to claim 1 or 2, characterized in that the evaluation means contain a microprocessor, with the help of which the rotational movement size and / or the position size is determined, and / or contain an analog / digital converter ( 2 ) with which the sensor means detected signals are implemented, and / or contain a filter device, in particular a low-pass filter, with which the distance variables detected by the sensor means are filtered. 9. The device according to claim 1 or 2, characterized in that
that additional sensor means are available with which variables ( 6 , 7 ), such as in particular the wheel speeds, the steering angle, the vehicle accelerations or the yaw rate, are detected, and
that in the evaluation means, depending on these: quantities, at least one vehicle movement quantity that describes the vehicle movement is determined, and
that, depending on this vehicle movement quantity and the determined rotation movement quantity and / or position quantity, a quantity value for the liquid present in the container, which value has been removed from vehicle movements, is determined. 10. A method for determining the position and / or the movement of a surface of a liquid which is contained in a container ( 11 ), which is located in particular in a vehicle,
are provided in the sensor means ( 1 ), by means of which distance variables which describe the distance between the sensor means and a plurality of regions of the liquid surface are recorded, and
in the evaluation means ( 2 , 3 , 4 ) are provided, by means of de rer from the detected distance variables at least one rotational movement variable, which describes the rotational movement of the liquid, is determined. 11. The method according to claim 10, characterized in that by means of the evaluation means from the detected distance  sizes also a layer size, which is the location of the liquid describes, is determined. 12. The method according to claim 10 or 11, characterized in that
that as a function of the location size, a first size is determined which describes the current vehicle acceleration and / or vehicle inclination, and / or
that a second quantity is determined as a function of the rotational movement quantity, which describes the current vehicle rotational movement. 13. The method according to claim 10, characterized in that that the distance sizes by ultrasonic measurement and / or by microwave measurement, in particular radar measurement, and / or can be detected by optical measurement. 14. The method according to claim 10 or 11, characterized featured, that with the help of the evaluation means depending on the determined rotational movement size and / or position size and the known dimensions of the container a quantity value for the liquid in the container is determined. 15. The method according to claim 10 or 11, characterized featured, that the detected distance variables and / or the determined Rotational movement size and / or the determined position size is filtered by the time by short-term Vehicle movement and / or vehicle acceleration on the To eliminate influences exerted on the liquid surface. 16. The method according to claim 10 or 11 thereby characterized that depending on sizes, especially depending on the wheel speeds, the steering angle, the vehicle accelerations or the  Yaw rate using additional sensor means are detected, at least one vehicle movement quantity, the describes the vehicle movement, is determined, and that in Dependency of this vehicle movement size and the determined rotational movement size and / or position size one of Vehicle movements adjusted quantity value for the in Existing liquid container is determined.