DE102015208364A1 - A method for determining properties of a ground on which a vehicle operable away from paved roads is moved - Google Patents

Abstract

The invention relates to a method for determining properties of a ground (101) on which a vehicle (100) operable away from paved roads is moved, wherein signals (141) are emitted in the direction of the ground (101) on which the vehicle ( 100), and wherein signals (142) reflected by the substrate (101) are detected as first measured values, wherein second measured values are determined which describe a movement of the vehicle (100) and / or a spatial orientation of the vehicle (100) wherein the first measured values are evaluated as a function of the second measured values and from which properties of the ground on which the vehicle is moved are determined.

Description

The present invention relates to a method and a determination unit for determining properties of a ground on which a vehicle operable off-paved roads is moved, a vehicle having such a determination unit, and a computing unit and a computer program for carrying out the method.

State of the art

It is known to determine the condition of a paved paved road in a road vehicle. For example, is from the DE 197 15 999 A1 a radar arrangement for road condition detection in a motor vehicle is known, in which a road section is illuminated in front of the motor vehicle, echo signals from the illuminated roadway cut are recorded and from this classification of the road condition in the road section in predetermined road condition categories is derived.

Disclosure of the invention

According to the invention, a method and a determination unit for determining properties of a subsoil on which a vehicle which can be operated away from paved roads is moved, a vehicle with such a determination unit and a computer unit and a computer program for carrying out the method are proposed.

Advantageous embodiments are the subject of the dependent claims and the following description.

In this context, a vehicle operable away from paved roads is understood to mean, in particular, a vehicle adapted to be moved on rough, unpaved, unpaved, unprepared terrain, for example in alpine, mountainous or mountainous terrain, in Sand dunes or in wetlands such as bog or swamp. In particular, the vehicle is moved on subsoil of snow, ice, rock, sand, gravel and / or asphalt. In contrast, a road vehicle is operable only on paved, asphalted.

The off-highway vehicle, in particular, may be designed as an all-terrain vehicle (for example, a Unimog, amphibious vehicle, or snowcat), an ATV (all-terrain vehicle, e.g., a quad), or a snowmobile. As snow groomers and snowmobiles mostly tracked vehicles for locomotion in the snow are called. The vehicle may be designed as a passenger transport vehicle or as a utility vehicle.

In the course of the process, signals, for example electromagnetic radiation, sound or ultrasound, are emitted in the direction of the ground on which the vehicle is being moved. The signals are emitted into the ground below the vehicle and / or into the ground in an area in front of the vehicle and reflected from there. These signals reflected from the background are recorded as first measured values. For this purpose, the determination unit comprises at least one receiver. The determination unit may in particular comprise a plurality of transmitters and / or receivers, which may each be arranged at different locations of the vehicle. In the course of the procedure, signals can be transmitted into the underground by means of dedicated transmitters. It is also possible to detect reflected signals without using dedicated transmitters. For example, by moving the vehicle over the ground as a by-product, signals such as sound or pressure waves (e.g., engine and / or road noise) may be emitted which are reflected in the ground and detected as first measurements.

Second measured values are determined which describe a movement of the vehicle and / or a spatial orientation of the vehicle. These second measured values in particular describe how the vehicle moves in space and / or how the vehicle is oriented or oriented in space, in particular relative to a reference point, for example relative to the ground. The determination unit has for this purpose at least one sensor.

The first measured values are evaluated as a function of the second measured values, and from this properties of the ground on which the vehicle is moved are determined. Depending on the properties of the ground and the depth at which the emitted signals are reflected, the corresponding reflected signals have different properties, for example different angles of incidence, different polarizations, etc. Differences between emitted and reflected signals are evaluated and conclusions are drawn about the properties of the background ,

Advantages of the invention

Off-road vehicles are usually not on paved, paved roads, but mostly in operated in rough terrain, in which the nature and properties of the ground can change quickly and unpredictably. The method provides a way to accurately determine the properties of the subsurface.

Even experienced drivers can find it very challenging and dangerous to move the vehicle on such rough terrain. The driver often can not respond quickly enough to changing properties of the ground, which results in an increased risk of accidents. The procedure for determining properties of the subsoil can eliminate these hazards. It can be ensured that it is known at all times on which special underground the vehicle is being moved.

Through this knowledge, the vehicle can adjust itself to changing properties of the ground and / or the driver can be notified of the current background properties in order to react accordingly. The safety for the driver and occupants of the vehicle can be increased.

The determination of the properties of the ground is carried out in particular during the drive of the vehicle. The signals are transmitted, received and evaluated in particular while driving. By considering the second measured values, the first measured values can also be precisely evaluated while the vehicle is moving, regardless of how fast the vehicle is moved.

Advantageously, sound waves reflected from the ground, which are emitted by an internal combustion engine of the vehicle, are detected as the first measured values. The sound waves are thus automatically emitted while driving into the ground below and into the ground in an area in front of the vehicle.

In particular, the second measured values describe how the transmitter and receiver move in space and how they are aligned in space or relative to the ground. The second measured values make known a current state of motion of the vehicle during the acquisition of the first measured values.

In particular, the second measured values are determined when the signals are emitted into the ground and / or when the signals reflected from the ground are detected. Due to the known time duration between transmission and reception of the signals, as well as by the known orientation of transmitter and receiver during this period of time, it is possible to deduce precisely the properties of the background.

In particular, a plurality of different measurements can be performed while the vehicle is traveling. The signals can be transmitted, for example, at predetermined time intervals, for example every 5 ms. 10 ms or 100 ms.

Advantageously, driving safety functions of the vehicle are carried out as a function of the determined properties of the subsoil. The driving safety functions can be adapted as soon as possible to changing characteristics of the subsoil and potential danger situations can be counteracted. An anti-lock braking system (ABS), an electronic stability program (ESP) and / or a traction control system (ASR) are preferably implemented as driving safety functions. As a driving safety functions, for example, a chassis or a damping of the vehicle can be changed.

For example, driving safety functions can be performed that detect slipping and / or stalling of the vehicle and initiate appropriate countermeasures. This is useful, for example, for a surface of ice, snow, sand.

In particular, driving safety functions may be performed which are specifically designed for off-road hazards, such as crevasse warnings, warning of a thin layer of ice, detection and warning of the danger of the vehicle breaking in on ice and sinking into underlying water.

For example, a driving safety function can be performed, by which a lifting of the vehicle from the ground is detected, for example, because the vehicle has been moved over a hill at too high a speed. This driving safety function is particularly suitable for snowmobiles and quads.

Preferably, properties of different layers of the substrate are determined. In particular, electromagnetic radiation is emitted whose frequency is suitably selected to penetrate to a desired depth in the ground. Advantageously, the frequency of the transmitted signals is changed. Thus, the signals can in particular penetrate into different layers of the ground. Alternatively or additionally, preferably a polarization, pulse duration and / or pulse width or Bandwidth of the transmitted signals changed. In particular, the best possible properties of the signals for examining the subsurface can thus be determined.

In the course of evaluating the first measured values as a function of the second measured values, a two-dimensional and / or three-dimensional map of the background is preferably determined, comparable to a B-scan or brightness scan in ultrasound examinations. The particular map may be used in particular for the driving safety functions. In particular, a two-dimensional and / or three-dimensional map of the surface of the substrate or the surface condition is determined. In particular, a two-dimensional and / or three-dimensional map of different layers of the subsurface can also be determined. Structures in the subsoil and their properties can thus be mapped in two or three dimensions.

By the second measured values it is known how the corresponding receivers are aligned relative to the ground and where they are when acquiring the first measured values. This information is assembled in the course of the evaluation to the two- or dimensional map. For a three-dimensional map in particular several signals are emitted in different directions. These emitted signals are reflected in different layers and at different places in the ground, whereby the three-dimensional map of the underground can be reconstructed in the course of the evaluation.

Preferably, a moisture and / or a density of the substrate material are determined as properties of the substrate. The specific composition of the substrate material can also be determined in particular.

Alternatively or additionally, the presence of a snow layer and / or its properties as background properties may preferably be determined. For example, a depth of the snow layer and / or properties of the snow may be determined, for example, whether the snow is fresh snow, powder snow, dry, loose snow, bound, strongly bonded snow, wet snow.

Alternatively or additionally, the presence of an ice layer and / or properties of this ice layer may preferably be determined as background properties. In particular, properties of background layers below this ice layer can be determined, in particular whether there is solid soil or water below the ice layer. In particular, when water is below the ice, it is determined how deep that water is. Thus, in particular, the danger can be recognized that the vehicle can break on the ice and sink into underlying water.

Furthermore, the presence of a crevasse may be determined as a characteristic of the subsoil, in particular the presence of snow-covered crevasses.

Preferably, the signals are emitted into the ground by means of a ground radar and the signals reflected from the ground are detected as first measured values. The ground radar comprises, in particular, the transmitters and receivers of the determination unit. By means of the ground radar electromagnetic radiation is emitted in particular with frequencies of at most 1 GHz. In particular, electromagnetic radiation having a frequency between about 16 MHz and 1 GHz is emitted. The lower the frequency, the lower the resolution of the smallest object in the ground that can be detected. Higher frequencies make it possible to use smaller antennas or smaller sensors.

Advantageously, a linear acceleration, in particular in at least one of the three spatial directions or along at least one of the three expansion axes of the vehicle (longitudinal, transverse, vertical axis) is determined as second measured values. Alternatively or additionally, an angle of inclination of the vehicle relative to a defined axis and / or a rate of rotation, that is to say a roll, pitch and yaw rate, more preferably corresponding roll, pitch and yaw angles, are determined as the second measured value. In particular, an angular velocity of a rotational movement about one of the three spatial directions or about one of the three expansion axes of the vehicle (longitudinal, transverse, vertical axis) is determined as the rotation rate. For this purpose, the determination unit preferably has at least one inertial sensor and / or at least one microelectromechanical system (MEMS).

Alternatively or additionally, for example, a speed of the vehicle, a driving torque provided by a drive of the vehicle, a rotational speed of the drive (eg internal combustion engine or electric motor), a voltage or drive current applied to an electric motor, a steering direction and / or a turning radius second measured values are determined.

An arithmetic unit according to the invention, e.g. a control device of a vehicle, is, in particular programmatically, adapted to perform a method according to the invention.

Also, the implementation of the method in the form of a computer program is advantageous because this causes very low costs, especially if an executive controller is still used for other tasks and therefore already exists. Suitable data carriers for the provision of the computer program are, in particular, magnetic, optical and electrical memories, such as hard disks, flash memories, EEPROMs, DVDs and the like. It is also possible to download a program via computer networks (Internet, intranet, etc.).

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

The invention is illustrated schematically by means of embodiments in the drawing and will be described below with reference to the drawing.

Brief description of the drawings

1 schematically shows a preferred embodiment of a designed as a snowmobile vehicle, which is adapted to perform a preferred embodiment of a method according to the invention.

2 schematically shows a preferred embodiment of a method according to the invention as a block diagram.

Embodiment (s) of the invention

In 1 is a preferred embodiment of an operable away from paved roads vehicle shown schematically and with 100 designated.

The snowmobile 100 has a drive 110 on, for example, an internal combustion engine 110 , The internal combustion engine 110 provides a drive torque, which via a transmission 111 For example, a continuously variable transmission is transmitted to a chain drive shaft. The drive torque is thus on a chain 112 of the snowmobile 100 transfer.

The snowmobile 100 will be on a surface 101 moved away from paved roads, especially in an impassable, unsecured, unpaved, unprepared terrain. In this example, the vehicle designed as a snowmobile 100 moved on a substrate of snow and / or ice. For example, a vehicle designed as a quad can also be moved on other surfaces, for example of rock, sand and / or gravel.

Properties of the subsoil 101 In the rough terrain can often change quickly and unpredictably. Often, even experienced drivers can not fast enough to changing properties of the ground 101 react, giving the driver control of the vehicle 100 can lose.

To counteract such dangerous situations, is the snowmobile 100 to set up a preferred embodiment of a method according to the invention for determining properties of the substrate 101 perform. For this purpose, the snowmobile points 100 a preferred embodiment of a determination unit 105 on.

The determination unit 105 has a ground radar 130 on. The ground radar includes several transmitters 131 and receiver 132 in different places of the snowmobile 100 are arranged. The transmitters 131 In this example, they are configured to receive signals in the form of electromagnetic radiation 141 in the underground 101 send out. The recipients 132 are set up from the underground 101 reflected signals 142 to capture as first measured values.

Furthermore, the determination unit 105 inertial sensors 151 . 152 on. By means of linear acceleration sensors 151 Linear accelerations along the three axes of extension of the snowmobile (longitudinal, transverse, vertical axis) are determined as second measured values. Using rotation rate sensors or gyroscopic sensors 152 become an inclination angle of the snowmobile 100 relative to a defined axis and a roll, pitch and yaw rate, (angular velocities about the three extension axes of the vehicle) and corresponding roll, pitch and yaw angles are determined as second measured values.

The determination unit 105 also has an arithmetic unit 120 on, which, in particular programmatically, is adapted to perform a preferred embodiment of a method according to the invention. The arithmetic unit 120 is preferably designed as a control unit of the snowmobile. The control unit 120 , the ground radar 130 and the inertial sensors 151 . 152 are in particular via a suitable communication system, for example via a CAN bus, data-transmitting connected to each other.

The preferred embodiment of the method according to the invention is shown schematically in FIG 2 shown as a block diagram.

The snowmobile 100 will be in the course of a regular trip over the underground 101 emotional. In a step 201 be from the broadcasters 131 electromagnetic radiation 141 in the underground 101 below the snowmobile 100 and in the underground 101 in a range of, for example, 10 meters in front of the snowmobile 100 sent out. In particular, different electromagnetic radiation 141 with different frequencies, different pulse widths or bandwidths, different polarizations and / or different pulse durations emitted.

The emitted electromagnetic radiation 141 penetrate different depths into the underground 101 and are reflected there. These reflected signals 142 be in step 202 from the recipients 132 recorded as the first measured values.

At the times at which reflected electromagnetic radiation 142 from the recipients 132 will be received, according to step 203 by means of inertial sensors 151 and 152 the linear accelerations, the inclination angle determines the roll, pitch and yaw rate and the roll, pitch and yaw angles as second measured values.

In step 204 will be in step 202 detected first measured values depending on the in step 203 evaluated according to certain second measured values. By the second readings, in step 202 It is known how stations are determined 131 and receiver 132 when acquiring the second measured values relative to the ground 101 are aligned and where they are located.

In the course of this evaluation, the differences between emitted and reflected electromagnetic radiation are determined by reflection on the ground 101 caused. For example, the differences in the frequency and polarization between the emitted and the reflected electromagnetic radiation are determined.

From these differences may be on the properties of that layer in the underground 101 be deduced, at which the respective emitted electromagnetic radiation 141 was reflected. Thus, in step 205 the properties of different layers of the subsurface 101 certainly.

In step 205 becomes in the course of the evaluation a two- and three-dimensional map of the surface of the underground 101 certainly. By knowing how the recipients 132 relative to the ground 101 are aligned and where they are located, can be reconstructed at which positions of the surface, the emitted electromagnetic radiation were reflected.

This in step 205 certain card as well as the one in step 204 certain properties will be in step 206 used for driving safety functions, which in particular also from the control unit 120 be executed. For example, the control unit executes a warning of crevasses as a safety function.

For this purpose, in step 204 For example, determined as properties of the subsoil, whether in lower-lying layers of the subsurface 101 Cavities are located. By means of the map can be checked whether these cavities are covered in particular by snow. If this is the case, in step 206 from the driving safety function issued a warning message to the driver of the snowmobile, for example by activating a warning light.

The emission of the electromagnetic radiation according to step 201 is performed at predetermined intervals, for example, every 5 ms, indicated by reference numerals 207 , The remaining steps become analogous as well 201 repeated until 206.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19715999 A1 [0002]

Claims (18)

Method for determining properties of a subsoil ( 101 ) on which an off-highway vehicle ( 100 ), where signals ( 141 ) in the direction of the underground ( 101 ) are sent out ( 201 ) on which the vehicle ( 100 ) and where from the ground ( 101 ) reflected signals ( 142 ) are recorded as first measured values ( 202 ), - whereby second measured values are determined ( 203 ), which is a movement of the vehicle ( 100 ) and / or a spatial orientation of the vehicle ( 100 ), wherein the first measured values are evaluated as a function of the second measured values and from this properties of the ground on which the vehicle is moved are determined ( 204 ). Method according to claim 1, wherein driving safety functions of the vehicle ( 100 ) depending on the particular characteristics of the subsoil ( 101 ) are executed ( 206 ). Method according to claim 1 or 2, wherein properties of different layers of the substrate ( 101 ). Method according to one of the preceding claims, wherein from the substrate ( 101 ) reflected sound waves from an internal combustion engine ( 110 ) of the vehicle ( 100 ) are transmitted when the first measured values are detected ( 202 ). Method according to one of the preceding claims, wherein signals ( 141 ) by means of at least one dedicated transmitter ( 131 ) are sent out ( 201 ). Method according to claim 5, wherein the signals ( 141 ) by means of a ground radar ( 130 ) are sent out ( 201 ). Method according to claim 5 or 6, wherein a frequency, a polarization, a pulse duration and / or pulse width of the emitted signals ( 141 ) to be changed ( 201 ). Method according to one of the preceding claims, wherein in the course of the evaluation of the first measured values as a function of the second measured values, a two-dimensional and / or three-dimensional map of the underground ( 101 ) is determined ( 205 ). Method according to one of the preceding claims, wherein as properties of the substrate ( 101 ), a moisture and / or a density of the base material, the presence of a snow layer, properties of this layer of snow, the presence of an ice layer, properties of this ice layer, and / or the presence of a crevasse ( 204 ). Method according to one of the preceding claims, wherein a linear acceleration, an inclination angle and / or a rotation rate of the vehicle are determined as second measured values ( 203 ). Arithmetic unit ( 120 ), which is adapted to perform a method according to any one of the preceding claims. Determination unit ( 105 ) for determining properties of a subsoil for a vehicle operable off-paved roads ( 100 ) - with at least one receiver ( 132 ) for receiving signals ( 142 ), - with at least one sensor ( 151 . 152 ) for acquiring measured values that describe a movement and / or a spatial orientation, and - with a computing unit ( 120 ) according to claim 9. Determination unit ( 105 ) according to claim 12 with at least one dedicated transmitter ( 131 ) for sending signals ( 141 ). Determination unit ( 105 ) according to claim 13 with a ground radar ( 130 ) for sending and receiving signals ( 141 . 142 ). Determination unit ( 105 ) according to one of claims 12 to 14 with an inertial sensor ( 151 . 152 ) for acquiring measured values that describe a movement and / or a spatial orientation. Vehicle ( 100 ) operable away from paved roads, with a destination unit ( 105 ) according to claim 12 to 15. Computer program comprising a computing unit ( 120 ) to perform a method according to any one of claims 1 to 10 when executed on the computing unit. Machine-readable storage medium with a computer program stored thereon according to claim 17.

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