EP2976655A1

EP2976655A1 - Positioning method and device

Info

Publication number: EP2976655A1
Application number: EP14721284.9A
Authority: EP
Inventors: Jörg Heuer; Anton Schmitt; Andreas Scholz; Martin Winter
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2013-05-17
Filing date: 2014-04-22
Publication date: 2016-01-27
Also published as: US20160116568A1; DE102013209235A1; CN105229489A; WO2014183961A1

Abstract

The invention relates to a positioning method and device. According to the invention, a measurement method is used when there is a fairly large distance between a vehicle and a charging station, said measuring method determining the distance by way of absolute propagation time measurement. In a proximity zone between the charging station and the vehicle a relative propagation time measurement between a plurality of received signals is carried out.

Description

description

Method and device for position determination The invention relates to methods and devices for position determination.

Various approaches are currently being discussed to "electrically" refuel electrified vehicles, such as DC charging of hybrid electric buses via a pantograph, where the pantograph, a type of pantograph, is lowered from above onto the electric bus. For example, the pantograph has 3 points of contact for DC +, DC- and GND (DC: DC, GND: ground) which must be connected to corresponding contacts on the electric bus, for which it is necessary for the bus to be positioned during charging Previous solutions for trams or trains work with simple pantographs that only need to make contact with the trolley wire because these vehicles are earthed via the rail itself With pantographs done relatively inaccurate ,

Furthermore, it is known to park vehicles or in the field of robotics to detect obstacles due to reflections of emitted ultrasonic waves and notify a user or control electronics accordingly.

Thus, the object of the present invention is to provide methods and apparatuses with which by means of ultrasound positioning of a charging unit of a vehicle relative to a charging device of a charging station in a simple manner, with a large catching range and with high accuracy is possible. The invention relates to a method for determining a position of a loading unit of a vehicle relative to a loading device of a loading station, comprising the following steps: assigning a first positioning unit to the loading device;

Assigning a second positioning unit to the loading unit;

Assigning a first sensor to one of the first or second positioning units;

Assigning at least two second sensors to the first or second positioning unit to which no first sensor has yet been assigned;

Determining a first and a second distance between the first sensor and one of the at least two second sensors by the following two steps:

a) If the first sensor of at least one of the two second sensors has a minimum distance, through

Sending a first signal from one of the at least two second sensors to the first sensor,

- Sending a second signal after receiving the first signal from the first sensor to one of the at least two second sensors and

Determining a first distance taking into account a signal propagation time of the first signal, a signal propagation time of the second signal and a propagation velocity of signals in air;

b) Otherwise by

Sending out a third signal by the first sensor and receiving the third signal by at least two of the at least two second sensors,

Determining a respective propagation time difference between the respective receiving of the third signal by in each case two of the at least two second sensors,

Determining a second distance by forming a point of intersection of a first and a second line, wherein through the respective line possible locations of the first sensor relative to one of the at least two th sensors are displayed, wherein at least the first line (ALI) is formed due to the running time difference. In the context of this method, a distinction is made in a position determination between a near or near field and a far or far field. The far range relates to the approach of the vehicle to the charging station, which involves a rather rough position determination of the vehicle to the charging station. Here, an absolute distance is calculated by absolute running time determination. In the vicinity between the vehicle and the charging station positioning must be very accurate, since only with exact positioning of the first and second charging unit, the energy flow can be optimally done, for example, in inductive charging. Therefore, in the near or short range, a more complex distance determination is performed compared to the far range. Here, the delay difference is determined upon receipt of a third signal by at least two of the second sensors. This has the advantage that disturbances in the vicinity of the first and the second sensors can, so to speak, be "averaged out", such as runtime differences due to snow or high air humidity, thus an advantage of the invention in the scalability of the complexity of the calculation steps In addition, the two-stage method makes it possible for a vehicle approaching the charging station to communicate by transmitting the first signal to the charging station, so that it can then be subsequently changed over from absolute to relative measurement The changeover can, for example, be signaled to the charging station or the first sensor to a specific signal.The term capture area is understood to mean the terms near and far range.The minimum distance, for example Im, defines the boundary between the near range and the far range after concrete implementation of the application, eg if the vehicle is a car or a tram, the minimum distance can be adjusted. Signals are wirelessly transferable signal waves which, even at short distances between see vehicle and charging station allow accurate measurements. Short distances are understood to mean distances of several meters to a few centimeters. Advantageously, the second line is formed by a transit time difference of two of the at least two second sensors, wherein none or only one of the second sensors is used in the generation of the first line. As a result, the position determination can also be carried out if no reference points for determining the position of the vehicle with respect to the charging station are present, such as a predetermined driving distance of the vehicle.

In an alternative development, the second line is determined on the basis of a route of the vehicle, wherein the second line runs parallel to the route and through the first sensor. This makes it possible to simplify the determination in determining the position of the vehicle with respect to the charging station in the vicinity.

In a particular embodiment of the invention, the first sensor of the first positioning unit and the at least two second sensors of the second positioning unit are arranged. As a result, the position determination by the vehicle, which can actively influence the approach to the charging station, be carried out.

In one embodiment of the invention, the first, second and / or third signal are transmitted at different frequencies or with different signal patterns. In this way, the determination of the distance can be carried out more accurately, since disruptive influencing variables, such as reflections or echoes of the signals, can be recognized and taken into account in the determination.

In an additional or alternative embodiment of the invention, in each case one of a respective arrangement of the first and / or at least one of the second sensors Aperture for signal shaping in a respective first or

second opening angle for the emission and the reception of the respective signal used. As a result, signal disturbances can be further reduced and manipulation attempts by third parties can be reduced or avoided.

Advantageously, the first and at least two second sensors operate with ultrasonic or radar waves. This has the advantage that already existing in the vehicle sensors can be used to carry out the positioning, whereby both a realization of the invention technically and in terms of cost significantly simplified and acceptance in the market introduction of the invention can be significantly increased.

The invention also relates to a device for determining a position of a charging unit of a vehicle relative to a charging device of a charging station, with

a first positioning unit of the loading device, a second positioning unit of the loading unit, a first sensor associated with one of the first or second positioning units,

at least two second sensors associated with the first or second positioning unit, which is not yet associated with a first sensor and

a determination unit for determining a first and a second distance between the first sensor and one of the at least two second sensors in which

- Determining a first distance, taking into account a signal delay of the first signal, a signal delay the second signal and a propagation speed of signals in air;

b) Otherwise by

Determining a second distance by forming a

Intersection of a first and a second line, wherein by the respective line possible locations of the first sensor relative to one of the at least two second sensors are displayed, wherein at least the first line is formed due to the running time difference.

The device shows the same advantages as the corresponding method. In a development, the device has another

A unit that is configured such that at least one of the method steps is implementable and executable. The device shows the same advantages as the corresponding method.

The invention and its variations will be described with reference to figures. In detail show:

Starting maneuver of a vehicle with a charging unit in the direction of a charging device of a charging station;

Determining a first distance in a remote area of the vehicle to the charging station;

Determining a position between the charging unit and the charging device in the near field of the vehicle to the charging station; Figure 4 is a flow chart describing the individual steps of the method. Elements with the same function and mode of operation are provided with the same reference numerals in the present application.

The invention and its variants are shown by means of ultrasonic sensors for sensors and ultrasonic signals for signals.

FIG. 1 shows a typical approach situation of a vehicle F, for example a bus, in the direction RI of a charging station LS. The vehicle has inter alia a charging unit LEF, for example in the form of a pantograph or several contact points on the roof of the bus. In addition, Figure 1 shows on the roof of the bus, a second positioning unit PE2 with 3 ultrasonic sensors US21, US22, US23. When assigning the second positioning unit to the loading unit, a local orientation of the loading unit to the arrangement of the second positioning unit or to the arrangement of the respective second sensors is known. In the present embodiment, the three second ultrasonic sensors are mounted in a row at a distance of 50 cm on the roof of the bus. The loading unit is housed in Figure 1 in a field of 50x50 cm, which is arranged at a distance of 30 cm parallel to the second positioning unit PE2. The charging station LS has a first positioning unit PE1 with a first ultrasonic sensor US1. In addition, the charging station, the charging device LVS, which is carried out, for example, of tensioned overhead lines that can transmit electrical energy through the charging device of the charging station and the charging unit of the vehicle in the battery of the vehicle after contacting the pantograph by the vehicle. In an alternative embodiment, the loader is multiple with a pantograph extendable contact points, which are extended after reaching a position of the vehicle under the charging station and contacted with the charging points of the charging unit and configured after creation of the contact for transmitting electrical energy.

In order to ensure correct charging of the battery of the vehicle by the charging station, the charging unit and the charging device must be positioned exactly to each other. For this purpose, it is necessary, during the approach of the vehicle to the charging station to repeatedly determine the position to each other in order to achieve the correct positioning can.

For this purpose, two different methods are used depending on the distance of the vehicle to the charging station. If the vehicle is located in the far field of the charging station, for example greater than 1 m, an absolute measurement of the distance between the first ultrasound sensor US1 and at least one of the second two ultrasound sensors US22 is first carried out. As can be seen in FIG. 2, second ultrasound sensor US22 transmits a first ultrasound signal SIG1, which is subsequently received by first ultrasound sensor US1. Following this, the first ultrasound sensor USl responds with a second ultrasound signal SIG2, which is subsequently received by the second ultrasound sensor US22. It is known to the second ultrasound sensor US22 at which point in time the first ultrasound signal was transmitted and the second ultrasound signal was received, that is to say the transit time DT of the first and second ultrasound signal. For example, this runtime is 100 ms. From this, a first distance ABS1 between the second ultrasonic sensor US22 and the first ultrasonic sensor US1 can be calculated by the following formula: ABS1 = DT / 2 * Va, where Va describes the propagation velocity of ultrasonic signals in air, Va = 343 m / s. In this example, the first distance is

ABS1 = 0.1s / 2 * 343 m / s = 17.15 m. The absolute measurement of the first distance between the first and the second ultrasonic sensor is performed in a simplified form, since it involves a first rough determination of the distance between the vehicle and the charging station. The determination of the first distance can be improved in that a speed of the vehicle during the

Performing the measurement, as well as an acceleration or deceleration of the vehicle during the measurement can be considered. In a further embodiment, the first ultrasonic sensor US1 delays the transmission of the second ultrasonic signal SIG2 by VT. This makes it possible to distinguish between the second ultrasonic signal SIG2 and an echo of the first ultrasonic signal SIG1 from surrounding objects. If, for example, VT = 500 ms is chosen, echoes of the first ultrasonic signal due to the attenuation of the first ultrasonic signal are no longer to be expected. In this embodiment, the first distance ABS1 can be calculated as follows: ABS1 = (DT-VT) / 2 * Va.

In a further embodiment, the measurement can be accelerated and still differentiated between the echo of the first ultrasound signal and the second ultrasound signal by the first ultrasound sensor for the second ultrasound signal using a frequency that differs from a frequency of the first ultrasound signal and sufficiently far is removed from the frequency of the first ultrasonic signal, so that this can not be generated by the Doppler shift during a movement of the vehicle from the first ultrasonic signal. Alternatively, the first and second ultrasonic signals may use the same frequencies, but with different amplitudes and / or signal characteristics. men. Thus, a rectangular signal is modulated onto the first ultrasonic signal while the second ultrasonic signal has a triangular signal. In a further development, different, preferably orthogonal, matching filter pairs are used for the modulation and detection of the first and second ultrasound signal for the first and the second ultrasound signal. One skilled in the art is aware of the use of matching filter pairs from the literature.

When the vehicle leaves the far-end area and is in close proximity to the charging station, e.g. between 0 m and 1 m, a second distance is determined. With the aid of FIG. 3, a determination of a second distance between the first ultrasonic sensor and at least one of the second ultrasonic sensors is explained in more detail below. For this purpose, the first ultrasonic sensor transmits a third ultrasonic signal SIG3, which is received by two of the second ultrasonic sensors US21, US22. Shows that the signal transit times to

Receiving the third ultrasonic signal SIG3 are identical by the two second ultrasonic sensors, that is, a first delay difference LZU1 is 0, the first ultrasonic sensor US1 is the same distance from the two second ultrasonic sensors. In this case, the location of the first ultrasonic sensor is to be found on a first line ALI, which corresponds to a straight line at a signal propagation time difference of 0. In this case, the first line passes through the first ultrasonic sensor and center between the two second ultrasonic sensors.

However, due to this relative measurement, not the explicit location but only the first line is known on which the first ultrasonic sensor is located at some point. For a precise determination of the position of the first ultrasonic sensor of the second ultrasonic sensors, a second line AL2 is required, wherein in an intersection of the first and second lines of the first ultrasonic sensor with respect to the second Ultrasonic sensors is located. There are two variants for forming the second line:

In a first variant, the vehicle moves on a predetermined route in the direction of the charging station. The second line AL2 can be formed by running parallel to the track of the vehicle and through the first ultrasonic sensor, ie parallel to the track. For example, there is a predetermined line on the road to the charging station that follows the vehicle to the charging station. Thus, at

Starting the vehicle to the charging station already defined the second line AL2. This is indicated in FIG. 3 with a line AL2 ^{1 V} which runs parallel to the distance AL2 'of the vehicle. At the intersection of the first and second lines is the location where the first ultrasonic sensor US1 is positioned. From this, the position of the first ultrasonic sensor with respect to the second ultrasonic sensors can be calculated. Thus, for example, a Cartesian coordinate system xy is spanned, in which the second distance can be determined by means of x and y components.

In a second variant, the first transit time difference LZU1 for the reception of the third ultrasound signal at the second ultrasound sensors US21, US22 and a second transit time difference LZU2 for the second ultrasound sensors US22, US23 are determined. The first and the second transit time difference, as explained in the previous example, result in the first and the second line ALI, AL2, which in each case have an elliptical shape in the case of non-zero transit time differences. In its intersection lies the location of the first sensor US1.

As Figure 3 illustrates, there may be, for example, in the second variant, two points of intersection. By aligning the second ultrasonic sensors in the direction of the first ultrasonic sensor, it follows that the first ultrasonic sensor can only lie in the local area from which the third ultrasound sensor is located. sound signal SIG3 is received. Thus, the unambiguous determination of the intersection point is possible.

In order to increase the measurement accuracy, the first, second and / or third ultrasound signal can be transmitted at different frequencies or with different signal patterns. In addition, ultrasound signals which are transmitted with a time delay can also be generated, for example when the third ultrasound signal is transmitted at intervals of, for example, 20 s, with different frequencies and / or different signal patterns in order to avoid or reduce erroneous measurements.

The examples presented relate to a configuration in which the first positioning unit is the first

Ultrasonic sensor and the second positioning unit has been assigned a plurality of second ultrasonic sensors. The invention can also be realized if the second ultrasonic sensors of the first positioning unit and the first ultrasonic sensor of the second positioning unit is assigned. Moreover, the long-range positioning determination can be improved by superposing two or more measurements. Furthermore, more than three second ultrasonic sensors can be used, whereby a measurement accuracy can be increased.

In a further embodiment, a respective first or second opening angle OW1, OW2 for the radiation and the reception of the ultrasonic signal is introduced for a respective arrangement of the first and the second ultrasonic sensors. For this purpose, as shown in Figure 5, the respective opening angle of the first ultrasonic sensor and at least one of the second ultrasonic sensors for the measurement in the far field in the direction of the position unit PE2 of the starting vehicle F on the position unit PE1 to be approached charging station LS aligned. The respective opening angle can be adjusted with a respective aperture in front of the respective ultrasonic sensor. In a further embodiment, the opening angles of the first ultrasonic sensor and at least one of the second ultrasonic sensors for the measurement in the far field are aligned such that these ultrasonic sensors, as shown in FIG. 5, can transmit mutually ultrasonic signals both in the far field and in the near field.

In a further embodiment, in each case at least three ultrasonic sensors are used both in the positioning unit PE1 and PE2. In this form, the position calculation is carried out in both positioning units and exchanged by communication and mutually checked. FIG. 4 shows a flow chart of the method according to the invention. This starts in state STA.

Subsequently, in the first step ST1, the assignment of the first positioning unit to the loading device and the assignment of the second positioning unit to the loading unit are undertaken.

In a second step ST2, an assignment of the first ultrasound sensor to one of the first or second positioning units and the assignment of at least two second ultrasound sensors to the first or second positioning unit, which is not yet associated with a first ultrasound sensor, are then performed. In the third step ST3 it is checked whether the vehicle is in the near or far field to the charging station.

If the vehicle is located in the far field, the first distance is determined in the following fourth step ST4 in such a way that first the first ultrasound signal from one of the at least two second ultrasound sensors is transmitted to the first ultrasound sensor, furthermore the second ultrasound signal after reception of the first ultrasound signal by the first ultrasonic sensor is returned to one of the at least two second ultrasonic sensors and the first distance is determined taking into account a signal propagation time of the first and the second ultrasonic signal and a propagation speed of ultrasonic signals in air.

Subsequently, in a sixth step ST6, it is checked whether the first distance indicates that the charging unit of the vehicle is already sufficiently accurately positioned with respect to the charging device of the charging station for a charging process. If this is the case, the state diagram is ended in step END.

Otherwise, the state diagram continues with the third step ST3. If the vehicle is in the near field of the charging station, a fifth step ST5 is performed instead of the fourth step ST4. In the fifth step, a third ultrasound signal is first emitted by the first ultrasound sensor and received by at least two of the at least two second ultrasound sensors, a respective transit time difference between the respective receiving of the third ultrasound signal determined by two of the at least two second ultrasound sensors and the second distance ABS2 by education determining an intersection point of a first and a second line, wherein possible locations of the first ultrasound sensor relative to one of the at least two second ultrasound sensors are indicated by the respective line, wherein at least the first line is formed on the basis of the running time difference.

If it results from the fifth step that the second distance, that is to say a distance between the charging station and the charging unit, is positioned sufficiently accurately to carry out a charging process, then the state diagram in the END state is ended. Otherwise, the state diagram is continued in step ST3. In a further variant, information about the authorization is impressed on the respective ultrasound signals, for example by amplitude, phase and / or frequency modulation. In this way manipulation attempts or disturbances of unwanted third parties can be avoided.

The invention has been explained in more detail with reference to ultrasonic waves and sensors, but is not limited to this type of wireless waves. Rather, any type of waves can be used that allow communication from a few centimeters to a few meters, such as radar waves. These are sent and received with the help of radar sensors. In addition, the method can be used in addition to loading with a pantograph also for inductive charging of vehicles, being used for the positioning of the vehicle with a receiving coil on a coil of the charging station. In a further form, the absolute field can be defined in the near field

Running time measurement and the measurement of the running time difference can be combined, so that errors due to signal delay delays can be detected, for. due to snow.

Claims

claims

Method for determining a position of a charging unit (LEF) of a vehicle (F) in relation to a charging device (LVS) of a charging station (LS), characterized by:

Assigning a first positioning unit (PE1) to the loading device (LVS);

Assigning a second positioning unit (PE2) to the loading unit (LEF);

Assigning a first sensor (US1) to one of the first or second positioning units (PE1);

Assigning at least two second sensors (US21, US22, US23) to the first or second positioning unit (PE2) to which no first sensor (US1) has yet been assigned; Determining a first and a second distance (ABS1,

ABS2) between the first sensor (US1) and one of the at least two second sensors (US21) by the following two steps:

a) If the first sensor (US1) of at least one of the two second sensors (US21, US22) has a minimum distance, through

Sending out a first signal (SIG1) from one of the at least two second sensors (US21) to the first sensor (US1),

- Sending a second signal (SIG2) after receiving the first signal (SIG1) from the first sensor (US1) to one of the at least two second sensors (US21) and

- Determining a first distance (ABS1) taking into account a signal propagation time of the first signal (SIG1), a signal propagation time of the second signal (SIG2) and a

Propagation speed of signals in air;

b) Otherwise by

Sending out a third signal (SIG3) by the first sensor (US1) and receiving the third signal (SIG3) by at least two of the at least two second sensors (US21,

US22),

- Determining a respective run time difference (LZU1, LZU2) between the respective receiving the third signal (US3) by in each case two of the at least two second sensors (US21, US22),

Determining a second distance (ABS2) by forming an intersection point (SPK) of a first and a second line (ALI, AL2), wherein the respective line (ALI,

AL2) possible locations of the first sensor (US1) with respect to one of the at least two second sensors (US21) are displayed, wherein at least the first line (ALI) is formed due to the running time difference (LZU1).

2. The method of claim 1, wherein

the second line (AL2) is formed by a transit time difference (LZU2) of two of the at least two second sensors (US22, US23), wherein none or only one of the second sensors (US23) is used in the generation of the first line (ALI) becomes.

3. The method of claim 1, wherein

the second line (AL2) is determined on the basis of a route of the vehicle (F), the second line (AL2) running parallel to the route and through the first sensor (US1).

4. The method according to any one of the preceding claims, wherein the first sensor (US1) of the first positioning unit

(PE1) and the at least two second sensors (US21, US22, US23) of the second positioning unit (PE2) are arranged.

5. The method according to any one of the preceding claims, wherein the first, second and / or third signal (SIG1, SIG2, SIG3) are transmitted at different frequencies or with different signal patterns.

6. The method according to any one of the preceding claims, wherein for each arrangement of the first and / or at least one of the second sensors (US1, US21, US22, US23) each have a diaphragm for signal shaping in a respective first or second opening angle (OW1, OW2) is used for the emission and reception of the respective signal.

7. The method according to any one of the preceding claims, wherein the sensor (US1) and the at least two second sensors

(US21, US22, US23) work with ultrasound or radar waves.

8. Device (VOR) for determining a position of a charging unit (LEF) of a vehicle (F) with respect to a charging device (LVS) of a charging station (LS), with

a first positioning unit (PE1) of the loading device (LVS),

a second positioning unit (PE2) of the loading unit (LEF),

a first sensor (US1) associated with one of the first or second positioning units (PE1),

at least two second sensors (US21, US22, US23) associated with the first or second positioning unit (PE2), which is not yet associated with a first sensor (US1) and

a determination unit (EMH) for determining a first and a second distance (ABS1, ABS2) between the first sensor (US1) and one of the at least two second sensors (US21) in which,

- Determining a first distance (ABS1) taking into account a signal propagation time of the first signal (SIG1), a signal propagation time of the second signal (SIG2) and a propagation speed of signals in air;

b) Otherwise by

- Sending a third signal (SIG3) by the first sensor (US1) and receiving the third signal (SIG3) by at least two of the at least two second sensors (US21, US22),

Determining a respective propagation time difference (LZU1, LZU2) between the respective receiving of the third signal (US3) by in each case two of the at least two second sensors (US21, US22),

- Determining a second distance (ABS2) by forming an intersection point (SPK) of a first and a second line (ALI, AL2), wherein by the respective line (ALI, AL2) possible locations of the first sensor (US1) relative to one of the at least two second sensors (US21) are displayed, wherein at least the first line (ALI) is formed on the basis of the running time difference (LZU1).

9. Device (VOR) according to claim 8,

with a further unit (EWT), which is designed such that at least one of the method steps according to one of claims 2 to 7 can be implemented and executed.