DE102019210921A1 - Localization of a vehicle based on uneven road surfaces - Google Patents

Abstract

The invention relates to a method for determining the position of a vehicle (101) which has at least one sensor for detecting unevenness in the ground (108a, 108b, 111, 113, 115); using a map in which at least one signal and an assigned position are entered; with the steps of detecting a signal from the sensor; and comparing the detected signal with the at least one signal entered on the map.

Description

The invention relates to a method according to claim 1, a method according to claim 2, a method according to claim 3, a control device according to claim 5 and a computer program according to claim 6.

The localization of vehicles using a global navigation system (GNSS) is inherently subject to certain inaccuracies. For the automated driving of a route, additional systems are required in addition to the GNSS in order to specify the position of the vehicle. Such systems use additional sensors which detect the surroundings of the vehicle and whose signals are evaluated by self-learning algorithms. The sensors are a cost driver. In addition, the self-learning algorithms require a considerable amount of training.

The invention is based on the object of improving the localization of a vehicle compared to the solutions known from the prior art. In particular, precise localization of the vehicle should be implemented in a cost-effective and time-efficient manner.

This object is achieved by the method according to the independent method claims, a control device according to claim 5 and a computer program according to claim 6. Preferred developments result from the dependent claim and the embodiment shown in the figure.

The common inventive idea on which the independent claims are based consists in utilizing unevenness in the ground on which a vehicle is traveling in order to localize the vehicle. The invention is based on the knowledge that unevenness in the floor can be distinguished from one another and thus clearly identified.

As a premise it is assumed that there are no two bumps that are alike. This makes it possible to clearly assign a position to bumps. If a vehicle drives over an unevenness in the ground, the position of the unevenness results from the position of the vehicle.

The implementation of the inventive idea requires a map of bumps. A corresponding method according to the invention is used to create such a map. The map can be a digital map, i.e. a data structure. The data structure is designed to store signals from at least one sensor for detecting unevenness in the ground and positions of a vehicle in such a way that a signal and a position can be uniquely assigned to one another. A position is therefore clearly assigned to each signal. Conversely, a signal is clearly assigned to each position. The card can be filled using a vehicle that has at least one sensor for detecting unevenness in the ground and at least one means for detecting the position of the vehicle. The vehicle is moving, i.e. the vehicle is moving while the method is being carried out.

Unevenness is an uneven area of the ground. An uneven area is an area whose surface contour is uneven, i.e. deviating from a plane. The ground is the ground on which the vehicle is traveling.

The at least one sensor is designed to detect unevenness that the vehicle drives over. If the vehicle drives over a bump, this is reflected in a signal from the sensor. The sensor outputs a signal that corresponds to the unevenness driven over.

The at least one means for detecting the position of the vehicle is any desired means, different from the sensor, which is designed to continuously detect the position of the vehicle. A GNSS is preferably used as a means for detecting the position of the vehicle.

• - Erfassen eines Signals des mindestens einen Sensors;
• - Erfassen der Position des Fahrzeugs, die das Fahrzeug zum Zeitpunkt der Erfassung des Signals einnimmt unter Verwendung des Mittels zur Erfassung der Position; und
• - Eintragen der erfassten Daten, d.h. des erfassten Signals und der erfassten Position, in die Karte, sodass das erfasste Signal und die erfasste Position einander zuordenbar sind.

To fill the card, the following steps are carried out:

• - Detecting a signal from the at least one sensor;
• Detecting the position of the vehicle which the vehicle is occupying at the time of the detection of the signal using the means for detecting the position; and
• - Entering the recorded data, ie the recorded signal and the recorded position, in the map so that the recorded signal and the recorded position can be assigned to one another.

These steps are preferably carried out iteratively.

In order to prevent each recorded signal from being entered into the map together with the recorded position of the vehicle and the memory requirements of the card from becoming excessively excessive, it is preferably checked whether the recorded signal corresponds to an unevenness. If it corresponds to a bump, it is entered on the map together with the recorded position of the vehicle at the time the signal was recorded. If, on the other hand, it does not correspond to an unevenness, that is to say if the area of the subsurface detected by the sensor is flat, there is preferably no entry in the map.

• - Erfassen eines Signals des mindestens einen Sensors; und
• - Vergleichen des erfassten Signals mit mindestens einem in die Karte eingetragenen Signal.

Another method according to the invention uses the map described above, preferably a map created by means of the method described above, to determine the position of a vehicle. It is a moving vehicle, ie the vehicle is moving while the method is being carried out. The vehicle has the sensor described above for detecting unevenness in the ground. To determine the position of the vehicle, the following steps are carried out:

• - Detecting a signal from the at least one sensor; and
• - Compare the detected signal with at least one signal entered in the card.

If the comparison shows that the signals match, the position of the vehicle can be deduced from the position assigned to the signal entered on the map. The position assigned to the signal entered on the map is therefore the position of the vehicle at the time the signal was detected. If the vehicle has the above-described means for detecting the position, for example a GNSS, the position determined according to the invention can be compared with the position detected by the means in order to be included as a correction factor if necessary.

• - Erfassen eines Signals des mindestens einen Sensors;
• - Ermitteln mindestens eines in die Karte eingetragenen Signals, dessen zugeordnete Position auf der Route liegt; und
• - Vergleichen des erfassten Signals mit dem mindestens einen in die Karte eingetragenen Signals.

If the vehicle follows a predetermined route, a deviation of the vehicle from the route can be detected by modifying the method described above. A target trajectory of the vehicle is referred to as a route. The vehicle has the at least one sensor described above. A card of the type described above is used to perform the following steps:

• - Detecting a signal from the at least one sensor;
• - Determination of at least one signal entered on the map, the assigned position of which is on the route; and
• - Compare the detected signal with the at least one signal entered on the card.

If the vehicle assumes the position that is assigned to the signal entered on the map, the sensor detects a signal that corresponds to the signal entered on the map. By comparing the two signals, it is then possible to check whether the vehicle is following the specified route without deviating. If there is no match, this indicates under the premise of a complete map that the vehicle is deviating from the route.

The methods described enable very precise detection of deviations. The methods are therefore preferred for autonomous, i.e. driverless vehicles, such as autonomously driving machines. For example, a tractor that drives autonomously in a loading station can be navigated using the method.

The methods described above are preferably developed in such a way that the at least one sensor is used to detect a vibration of the vehicle or a part thereof that is excited when driving over the bump. This implies that the sensor is a vibration sensor. The sensor can be arranged, for example, on the body of the vehicle or in the vicinity of its wheels or on the chassis or frame.

The signal recorded by a vibration sensor is vehicle-specific. In particular, the signal depends on the mass of the vehicle. A map is therefore preferably used which takes into account the different load conditions of the vehicle. For example, a vehicle mass can be assigned uniquely to the signals and positions that can be assigned to one another.

A control device according to the invention for use in a vehicle of the type described above is designed to carry out one or more of the methods described above. A corresponding computer program according to the invention is designed to cause the control device to execute the method or methods when it is executed on the control device.

• 1 zwei Routen eines Fahrzeugs.

A preferred embodiment of the invention is shown in 1 shown. In detail shows:

• 1 two routes of a vehicle.

The in 1 depicted vehicle 101 it is an autonomous vehicle that follows a target route 103 from a starting point 105 to one goal 107 should follow. Along the target route 103 there is a first threshold 108a and a second threshold 108b that the vehicle 101 would run over if it was the target route 103 follows.

The vehicle 101 has a vibration sensor. When driving over uneven ground, the vehicle will 101 stimulated to vibrations, which the sensor converts into a corresponding signal. The signal can therefore be used to draw conclusions about the nature of the subsurface. In particular, the signal can be used to identify unevenness.

In 1 is a second route 109 drawn. This is an actual route taken by the vehicle 101 follows, and which is different from the target route 103 differs. On his way along the actual route 109 drives the vehicle 101 via a first manhole cover 111 . At the corresponding point on the target route 103 is the underground. That when driving over the first manhole cover 111 The sensor signal output therefore deviates from the expected signal when following the target route 103 from. It can be concluded that the vehicle 101 of the target route 103 has left.

There is a contact stone in the further course of the actual route 113 . The vehicle brushes against this 101 if it's the actual route 109 follows. It would be the target route 103 it would follow the contact stone 113 however drive around. A vibration signal generated when the contact stone is touched 113 is output by the sensor, therefore does not correspond to the signal expected at this point. It can be concluded that the vehicle 101 still one of the target route 103 follows a different route.

The actual route 109 leads the vehicle 101 on the first sill 105 past. At this point too, there is therefore a discrepancy between the signal output by the sensor and the signal that is generated when the actual route is followed 103 would be expected. This again indicates that the vehicle is 101 from the target route 103 has deviated.

The second sill 107 however, the one on the target route 103 the vehicle passes 101 if it's the actual route 109 follows. There is therefore no deviation from the actual route 109 from the target route 103 recognized.

In the further course of the target route 103 there is a second manhole cover 115 . The vehicle would do this 101 run over if it is the target route 103 follows. The actual route 109 leads the vehicle 101 but on the second manhole cover 115 past. The one when driving over the second manhole cover 115 The expected signal curve is therefore not recognized here. Thus it can again be assumed that the vehicle 101 from the target route 103 has deviated.

List of reference symbols

101

vehicle

103

Target route

105

Starting point

107

target

108a

first threshold

108b

second threshold

109

Actual route

111

first manhole cover

113

Contact stone

115

second manhole cover

Claims (6)

Method for creating a map by means of a vehicle (101) which has at least one sensor for detecting unevenness in the ground (108a, 108b, 111, 113, 115) and at least one means for detecting the position of the vehicle; with the steps - Detecting a signal from the at least one sensor; - Detecting the position of the vehicle (101) at the time of detection of the signal; and - Entering the recorded data on the card. Method for determining the position of a vehicle (101), which has at least one sensor for detecting unevenness in the ground (108a, 108b, 111, 113, 115); using a map in which at least one signal and an assigned position are entered; with the steps - Detecting a signal from the at least one sensor; and - Compare the detected signal with the at least one signal entered on the card. Method for recognizing a deviation of a vehicle (101) from a predetermined route (103); wherein the vehicle (101) has at least one sensor for detecting unevenness (108a, 108b, 111, 113, 115) of the ground; and using a map in which at least one signal and an assigned position are entered; with the steps - Detecting a signal from the at least one sensor; - Determination of at least one signal entered on the map, the assigned positions of which are on the route; and - Compare the detected signal with the at least one signal entered on the card. Method according to one of the preceding claims; characterized in that a shrinkage excited when driving over the unevenness (108a, 108b, 111, 113, 115) is detected by means of the at least one sensor. Control device for use in a vehicle (101); characterized in that the control device is designed to carry out at least one method according to one of the preceding claims. Computer program which is designed for a control device according to the preceding claim Execution of at least one method according to one of the Claims 1 to 4th when the computer program is executed on the control unit.

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