DE102018109659A1 - Distance control between two vehicles - Google Patents

Abstract

The invention relates to a method for controlling the distance between two vehicles (12), in particular for driving in a convoy (10), comprising the following steps: emitting first ultrasound signals (34) from a first vehicle (12), receiving those from the first vehicle (12). 12) emitted first ultrasonic signals (34) with a second vehicle (12), emitting a second ultrasonic signal (36) from the second vehicle (12) with a predetermined delay to each received first ultrasonic signal (34), receiving the from the second vehicle (12) transmitting second ultrasonic signals (36) to the first vehicle (12), determining a time difference between transmitting the first ultrasonic signal (34) and receiving the second ultrasonic signal (36) by the first vehicle (12), and determining a distance (32) between the first and second vehicles (12) based on the time difference minus the deceleration by the first vehicle (12). The invention also relates to a vehicle convoy (10) having a plurality of vehicles (12), wherein the vehicles (12) of the vehicle convoy (10) are designed to carry out the method according to one of the preceding claims 1 to 13.

Description

The present invention relates to a method for distance control between two vehicles, in particular for driving in a column.

Also, the present invention relates to a vehicle convoy having a plurality of vehicles, the vehicles of the vehicle convoy configured to perform the above method.

The vehicle convoy may comprise any number of vehicles, which may be designed differently. The vehicles are preferably trucks. The vehicles drive in the vehicle convoy to reduce air resistance and thus consumption at a distance of for example seven to twelve meters in a row. The vehicle convoy typically travels at a speed of about 80 km / h as typical speed for trucks. As a result, otherwise usual safety distances when driving in a column can sometimes be significantly undercut. Driving in a vehicle convoy can in principle be carried out on any road. However, vehicle convoys preferably travel on highways or similar roads which, for example, have separate lanes for each direction of travel and therefore require little interaction with other road users.

A first vehicle of the vehicle crew takes over the leadership of the convoy, and the following vehicles drive in a manner adapted to the leading vehicle. Preferably, the following vehicles are designed to automatically follow the respective preceding vehicle. Thus, only the leader of a vehicle crew leader vehicle must actively guide his vehicle or monitor the guidance of an autonomous control system. Vehicle drivers of the succeeding vehicles may perform activities that are independent of driving the vehicle, such as administrative activities, while driving in the vehicle crew. Driving in the vehicle convoy is thus carried out autonomously by a driving support system, at least in the following vehicles, whereby communication with other vehicles of the convoy can take place.

When driving in the vehicle convoy, it is necessary that the vehicles of the vehicle convoy, for example, maintain safety distances between the individual vehicles. Accordingly, a detection of objects in front of the respective vehicle is carried out. Existing vehicle support systems typically use LiDAR-based sensors, particularly laser scanners, radar sensors and / or optical cameras, to detect an environment of the vehicle and detect and track objects in the environment. This is very complex and associated with high costs. Due to the distances between the vehicles of seven to twelve meters, conventional, low-cost ultrasonic sensors that emit an ultrasonic pulse and receive echoes thereof, and which are widely used in the automotive industry, can not be used. Their range is typically less than the usual distances between vehicles in the convoy.

In this context is from the DE 10 2015 211 117 A1 discloses a convoy travel control system for a convoy with a leader vehicle and at least one follower vehicle automatically following the leader vehicle. Each of the vehicles of the convoy comprises a vehicle-to-vehicle communication device configured to send at least one vehicle parameter of the vehicle to a following vehicle and to receive the vehicle parameter of a preceding vehicle. Furthermore, each of the vehicles of the convoy comprises a vehicle-to-vehicle control device that is configured to control the vehicle parameter of the vehicle based on the received at least one vehicle parameter of the preceding vehicle.

Furthermore, from the DE 10 2015 213 888 B4 a control device of a vehicle known. The controller includes an interface configured to communicate with an ultrasonic transceiver of the vehicle and at least one processor configured to receive, via the interface, a signal detected by the ultrasonic transceiver. The processor is further configured to demodulate the signal for obtaining packetized data, wherein the packetized data includes a driving parameter of an adjacent vehicle.

The processor is further configured to trigger a driver assistance function based on the drive parameter.

The DE 10 2016 110 001 A1 relates to a system for data transmission and distance determination and / or adjustment of the distance between vehicles. The system determines the distance between at least two vehicles by means of data transmission signals.

From the EP 1 788 749 B1 For example, a method and apparatus for vehicle-to-vehicle multi-hop broadcast communication is known. The method for ad hoc network communication comprises determining position data of a receiving vehicle, wherein the position data of the receiving vehicle include a position, a speed and a direction of the receiving vehicle. The method further comprises receiving position data from transmitting vehicles, the position data of a transmitting vehicle comprising a position, speed and direction of the transmitting vehicle. The method further includes calculating a relative position, a relative speed and a relative direction between the receiving vehicle and the transmitting vehicle, and calculating a density of vehicles from the calculated relative positions. In addition, the method comprises periodically transmitting the position data of the receiving vehicle, wherein a time for periodically transmitting the position data of the receiving vehicle is set in accordance with the density of the vehicles.

The US 6,965,829 B2 *** "" Provides an on-vehicle electronic device having a wireless communication unit that performs wireless communication via a wireless LAN, and a device for acquiring position information and speed information of vehicles before and after the own vehicle using the wireless communication unit. The apparatus further comprises means for calculating the inter-vehicle distances between the own vehicle and the vehicles before and after the own vehicle with reference to map information based on the detected position information and speed information, and means for performing a collision avoidance measure when a calculated inter-vehicle distance is equal to or smaller than a predetermined one Distance and the speeds of the own vehicle and the vehicles before and after the own vehicle are equal to or higher than a predetermined speed.

Based on the above-mentioned prior art, the invention is therefore based on the object of specifying a method for distance control between two vehicles and a vehicle column with a plurality of vehicles, which allow a reliable and cost-effective distance control between two vehicles, especially when driving in a column.

The object is achieved by the features of the independent claims. Advantageous embodiments of the invention are specified in the subclaims.

According to the invention, a method for distance control between two vehicles is thus specified, in particular for driving in a convoy, comprising the following steps: emitting first ultrasonic signals from a first vehicle, receiving the first ultrasound signals emitted by the first vehicle with a second vehicle, emitting a second one Ultrasonic signal from the second vehicle with a predetermined delay to each received first ultrasonic signal, receiving the second ultrasonic signals emitted from the second vehicle with the first vehicle, determining a time difference between the emission of the first ultrasonic signal and receiving the second ultrasonic signal by the first vehicle, and Determining a distance between the first and second vehicles based on the time difference minus the deceleration by the first vehicle.

According to the invention, a vehicle convoy is also indicated with a plurality of vehicles, wherein the vehicles of the vehicle convoy are designed to carry out the above method.

The basic idea of the present invention is thus to detect a distance between two vehicles with ultrasound signals. In this case, the transmission of the first ultrasound signal from the first vehicle to the second vehicle and the transmission of the second ultrasound signal from the second vehicle to the first vehicle enable the use of conventional ultrasound sensors. A common range of application of the ultrasonic sensors for monitoring a maximum distance range of usually five to seven meters can be extended by the second vehicle, starting from the first ultrasonic signal, the second ultrasonic signal in a timely manner with a known delay sends back. Thus, use of the ultrasonic sensors for distances of typically ten to twelve meters or more is made possible, whereby the method can be carried out reliably in particular in a vehicle column with small distances between the vehicles with conventional ultrasonic sensors. Only conventional ultrasonic sensors are used, which are available at low cost, so that a cost-effective monitoring of distances between the vehicles is made possible. This applies in particular to driving in a vehicle convoy, in which shorter safety distances can be used in comparison with individual traffic, which can be covered with the extended range of the ultrasonic sensors. The method can also be carried out with ultrasound sensors known per se, which are used, for example, in parking aid systems and are therefore available at low cost. The distance control can thus be carried out in a vehicle with such a parking aid system, without additional hardware in the form of further ultrasonic sensors is required. When driving the parking assistance system is typically not active, so that the Parking assistance system experiences no limitation in its function. In vehicles that are already equipped with appropriate ultrasonic sensors, the method can thus be carried out inexpensively by an additional use of the existing ultrasonic sensors for distance control when driving in the vehicle convoy.

In order to avoid mixing of different ultrasound signals emitted by the first vehicle, it is preferred that exactly one first ultrasound sensor of the first vehicle emit the first ultrasound signals. Further first ultrasonic sensors of the first vehicle are preferably deactivated or passive in order to avoid disturbances in the reception of the ultrasound signals emitted by the first ultrasonic sensor by the second vehicle. The passive ultrasound sensor itself does not emit ultrasonic signals but can receive, for example, ultrasound signals including reflections of emitted ultrasound signals. The same applies to the transmission of the second ultrasonic signals from the second vehicle.

In order to be able to carry out the method universally with different vehicles, it is necessary for the delay in the transmission of the second ultrasonic signal after the reception of the first ultrasonic signal to be known. The delay can accordingly be specified globally for all vehicles. Alternatively, the delay in forming the vehicle crew may each be individually set, either by an operator setting or by communication between the vehicles of the vehicle crew. In principle, it is also possible for the second ultrasound signal to contain coded information that specifies the delay. The first vehicle can therefore decode the delay when receiving the second ultrasonic signal from the second ultrasonic signal and take into account for determining the distance. Thus, the process can be carried out very flexibly and without a specific configuration of the vehicles of the column.

The distance control procedure is given here for two vehicles. However, the method can be easily extended to a plurality of vehicles in order to form a correspondingly larger vehicle convoy. In this case, each vehicle except the leading and the last vehicle at the same time first and second vehicle with respect to the respective subsequent vehicle or the preceding vehicle. Only the leading vehicle and the last vehicle of the vehicle convoy only take on a role as first or second vehicle.

In principle, the vehicle column may comprise any number of vehicles of different design in principle. The vehicles are preferably trucks, which drive in order to reduce air resistance and thus to reduce fuel consumption at a distance of, for example, seven to twelve meters in a row. At least all of the vehicles following a vehicle convoy vehicle include a driving support system that controls driving in the vehicle convoy. The driving support system is designed to monitor the distance between the first and second vehicle, in particular a falling below a minimum distance between the two vehicles. Driving in the vehicle convoy is thus carried out autonomously by a driving support system, at least in the following vehicles, whereby communication with other vehicles of the convoy can take place.

Intervals between the first ultrasound signals may be selected, for example, as a function of a signal duration of the respectively emitted ultrasound signals and / or a range to be achieved and / or taking into account typical delays. In principle, it is possible that a plurality of first ultrasonic signals are emitted before a second ultrasonic signal is received. To distinguish which first ultrasonic signal belongs to a received second ultrasonic signal, associated first and second ultrasonic signals may be of the same design or contain the same identification. Successive first ultrasonic signals may be formed differently in pairs or in groups of a plurality of first ultrasonic signals or may contain a different identification. In principle, the emission of the first or second ultrasound signals is independent of the reception of the ultrasound signals, in particular if a plurality of ultrasound sensors are used on the first or second vehicle. The sending and receiving can also be done simultaneously.

When receiving the first ultrasound signals emitted by the first vehicle as well as when receiving the second ultrasound signals emitted by the second vehicle, for example, a beginning of the respective ultrasound signal is to be considered as a so-called trigger in order to determine the distance between the two vehicles depending thereon. In particular, in the case of an ultrasound signal with a digital modulation, it is also possible to use the modulation for the synchronization and determination of the reception time interval. In this case, for example, by means of a digital modulation with typically steep edges, an exact time determination can be carried out on such an edge, alternatively in combination several flanks. In contrast, analog signals usually have less steep edges and therefore only allow a lower accuracy in the determination of the reception time interval.

The vehicles of the vehicle crew jointly carry out the above procedure. Different vehicles can take on different roles at the same time or one after the other depending on their position.

The first vehicle may in principle comprise an ultrasonic sensor for emitting the first ultrasonic signals, which also receives the second ultrasonic signal emitted by the second vehicle. Alternatively, the first vehicle may include one or more other ultrasonic sensors that receive or receive the second ultrasonic signal emitted by the second vehicle. In this case, an ultrasonic sensor can exclusively perform the emission of the first ultrasonic signals.

The second vehicle may in principle comprise an ultrasonic sensor for receiving the first ultrasonic signals from the first vehicle, which also transmits the second ultrasonic signal. Alternatively, the second vehicle may include one or more other ultrasonic sensors that receive or receive the first ultrasound signal emitted by the first vehicle. In this case, an ultrasonic sensor can exclusively perform the emission of the second ultrasonic signals.

The distance between the first and second vehicles may be compared with a predetermined distance to the distance control to determine deviations. It can be controlled in particular a falling below a minimum distance between the two vehicles. Also, for distance control based on temporally consecutive distance determinations, a change in the distance can be determined dynamically.

In an advantageous embodiment of the invention, the first vehicle is a preceding vehicle, the second vehicle is a subsequent vehicle, and the step of determining a distance between the first and second vehicles is performed by the preceding vehicle. Thus, the first vehicle as a preceding vehicle can directly determine the distance and perform the distance control to take a countermeasure as necessary. The preceding vehicle can quickly and efficiently reduce the distance to the following vehicle by braking. Also, the preceding vehicle may send control commands to the immediately following vehicle or all subsequent vehicles based on the determined distance.

In an advantageous embodiment of the invention, the first vehicle is a subsequent vehicle, the second vehicle is a preceding vehicle, and the step of determining a distance between the first and second vehicle is performed by the subsequent vehicle. Thus, the first vehicle as the following vehicle can directly determine the distance and perform the distance control to take a countermeasure as necessary. The following vehicle can quickly and efficiently perform an increase in the distance to the preceding vehicle by braking. Delays in increasing the distance by a possibly required signaling between the vehicles omitted, so that the increase in the distance can be effected quickly and reliably. In addition, the subsequent vehicle may send control commands to the preceding vehicle or all vehicles of the column based on the determined distance.

In an advantageous embodiment of the invention, the method comprises an additional step for transmitting the distance between the first and second vehicles from the first vehicle to the second vehicle via a communication link. This includes a transmission of the distance, a result of the distance control or even a control command for changing the distance between the two vehicles, so that both vehicles can actively establish a desired distance. Thereby, the control for keeping the distance with the first and second vehicles is performed together. By combining the control functions, the control of the second vehicle can take place with additional consideration of the control of the first vehicle. Control as a countermeasure based on the distance control may be performed by both the first vehicle and the second vehicle, or in combination, i. decreasing the distance between the vehicles may accelerate the preceding vehicle, delay the following vehicle, or both. The same applies vice versa with an increase in the distance.

In an advantageous embodiment of the invention, the method comprises a step for receiving a speed of the first and / or the second vehicle. The vehicles and thus the vehicle column as a whole can perform additional measures with additional consideration of the speed starting from the distance control. Thus, depending on a reduction in the distance between the two vehicles be adjusted by the speed of a braking maneuver. For example, at a high speed, emergency braking may be initiated while at low speeds, a less intense braking maneuver is performed. The same applies in principle for an acceleration, since at higher speeds greater air resistance occurs, which makes the acceleration difficult.

In an advantageous embodiment of the invention, the method comprises an additional step for focusing the first ultrasound signals emitted by the first vehicle and an additional step for focusing the second ultrasound signals emitted by the second vehicle. This relates to a corresponding control of the respective ultrasonic sensor. Alternatively or additionally, a hardware modification of the respective ultrasonic sensor is possible. By focusing the ultrasound signals emitted by the first and second vehicles, a greater range of the ultrasound signals can be achieved, thereby facilitating the use of conventional ultrasound sensors. Energy of the first and second ultrasonic signals emitted from the first and second vehicles, respectively, may be converged for each other vehicle to receive the ultrasonic signal at a sufficiently high level. When focussed purely by a modified control, the ultrasonic distance control sensors according to the present invention can also be used in a known manner for detecting obstacles, for example when parking, in which case each ultrasonic sensor itself receives echoes of the ultrasound signals radiated by it, by a distance of the objects capture.

In an advantageous embodiment of the invention, the method comprises an additional step for attaching the ultrasonic sensor to the first and / or second vehicle at a height of at least 80 cm above a ground level, preferably at least one meter above ground level, more preferably at least 1.25 meters above ground level , The attachment of the ultrasonic sensor at a corresponding height helps to prevent reflections of the ultrasonic signals, for example on a road surface. In particular, when attaching the ultrasonic sensors to a truck, a corresponding height can be readily realized.

In an advantageous embodiment of the invention, the method comprises an additional step for adjusting a distance between the first and the second vehicle based on the determined distance. The adaptation of the distance can be carried out in principle by delaying and / or accelerating at least one of the vehicles. The adaptation may be performed jointly by the first vehicle or the second vehicle or both vehicles. Additionally, signaling between the first and second vehicles may be performed to perform the adjustment of the distance together. The adaptation may be accomplished by changing the speed of the preceding vehicle, i. delay or accelerate, or a change in the speed of the following vehicle, i. delay or accelerate. This may include that the following vehicle performs an emergency braking, for example, when the distance control of the distance between the two vehicles results in falling below a minimum distance.

In an advantageous embodiment of the invention, the step of transmitting first and second ultrasound signals from the first and second vehicle, respectively, comprises emitting coded first and second ultrasound signals. The emission of coded ultrasound signals makes it possible to associate the ultrasound signals with a specific vehicle or even a single ultrasound sensor. Accordingly, each vehicle or each ultrasonic sensor transmits coded ultrasonic signals with an individual code. The code can be different for each vehicle. Confusion in receiving the ultrasonic signals can be avoided, whereby a change in the distance between two vehicles can be determined with a high reliability.

In an advantageous embodiment of the invention, the step of transmitting coded first or second ultrasound signals comprises emitting the first and second ultrasound signals with a corresponding first or second code. Thus, for example, echoes of the first ultrasonic signals can be distinguished from the second ultrasonic signals on the side of the first vehicle. The second ultrasonic signals can be reliably identified in order to be able to reliably determine the distance between the first and second vehicles. Confusion of the second ultrasonic signals with echoes of the first ultrasonic signals or with other ultrasonic signals can be avoided with appropriate coding.

In an advantageous embodiment of the invention, the method comprises an additional step for receiving echoes of the first ultrasound signals emitted by the first vehicle. By receiving and evaluating the echoes of the first ultrasonic signals, the echoes of the first ultrasonic signals may be used in addition to determining distances. It is one corresponding control of at least one ultrasonic sensor of the first vehicle required to receive the echoes of the first ultrasonic signals with the first code. In particular, the echoes may be received when the distance between the first and second vehicles is within a sensor range of the ultrasonic sensors in a common use.

In an advantageous embodiment of the invention, the method comprises an additional step for emitting third ultrasound signals from the second vehicle and receiving echoes of the third ultrasound signals emitted by the second vehicle. The ultrasonic sensors of the second vehicle can thus also be used to collect distance information in the usual way. In this case, the echoes of the third ultrasound signals can be distinguished, for example, from the first ultrasound signals emitted by the first vehicle in order to prevent interference. In particular, the echoes may be received when the distance between the first and second vehicles is within a sensor range of the ultrasonic sensors in a common use. In principle, echoes of the second ultrasonic signals can also be used to collect distance information in the usual way.

In an advantageous embodiment of the invention, the step of transmitting first and second ultrasound signals from the first and second vehicle, respectively, comprises emitting ultrasound signals with a modulated information signal, and the step of receiving the first and second ultrasound signals with a second and first vehicle, respectively includes demodulating the ultrasonic signals and receiving the information signal. The modulation is preferably carried out according to the BPSK standard. The information signal can in principle contain any information. For example, the information signal may be used for communication between the first and second vehicles to jointly control the vehicles in the column.

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments. The illustrated features may represent an aspect of the invention both individually and in combination. Features of various embodiments are transmittable from one embodiment to another.

• 1 eine schematische Ansicht einer Fahrzeugkolonne mit einer Mehrzahl Fahrzeuge beim Fahren auf einer Fahrbahn gemäß einer ersten, bevorzugten Ausführungsform,
• 2 eine detaillierte Ansicht von zwei Fahrzeugen der Fahrzeugkolonne aus 1 mit Ultraschallsensoren und einer Kommunikationsverbindung zur Durchführung eines Verfahrens zur Abstandskontrolle in Übereinstimmung mit der ersten Ausführungsform,
• 3 eine schematische Detailansicht eines Fahrzeugs in Übereinstimmung mit der Fahrzeugkolonne aus 1 mit einem Fahrunterstützungssystem zur Durchführung eines Verfahrens zur Abstandskontrolle in Übereinstimmung mit der ersten Ausführungsform,
• 4 ein Ablaufdiagramm eines Verfahrens zur Abstandskontrolle für die Fahrzeuge der Fahrzeugkolonne aus 1 in Übereinstimmung mit der ersten Ausführungsform,
• 5 eine schematische Ansicht einer Abstandsmessung basierend auf einem von einem ersten Fahrzeug ausgesendeten ersten Ultraschallsignal und einem von dem ersten Fahrzeug empfangenen Echo des ersten Ultraschallsignals, und
• 6 eine schematische Ansicht einer Abstandsmessung basierend auf einem von einem ersten Fahrzeug ausgesendeten ersten Ultraschallsignal und einem von dem zweiten Fahrzeug als Antwort auf einem Empfang des ersten Ultraschallsignals ausgesendeten zweiten Ultraschallsignals.

It shows

• 1 2 a schematic view of a vehicle column with a plurality of vehicles when driving on a roadway according to a first preferred embodiment,
• 2 a detailed view of two vehicles of the vehicle convoy 1 with ultrasonic sensors and a communication link for carrying out a distance control method in accordance with the first embodiment,
• 3 a schematic detail view of a vehicle in accordance with the vehicle convoy 1 with a driving support system for carrying out a distance control method in accordance with the first embodiment,
• 4 a flowchart of a method for distance control for the vehicles of the vehicle convoy 1 in accordance with the first embodiment,
• 5 3 is a schematic view of a distance measurement based on a first ultrasound signal emitted by a first vehicle and an echo of the first ultrasound signal received by the first vehicle, and FIG
• 6 5 is a schematic view of a distance measurement based on a first ultrasound signal emitted by a first vehicle and a second ultrasound signal emitted by the second vehicle in response to a receipt of the first ultrasound signal.

The 1 shows a vehicle convoy 10 with a plurality of vehicles 12 when driving on a roadway 14 according to a first, preferred embodiment of the invention.

The vehicle crew 10 is exemplary here with four vehicles 12 illustrated, but in other embodiments, in principle any number of principally different running vehicles 12 include. The vehicles 12 are in 1 as a truck running a distance 32 from, for example, seven to twelve meters in between. All one the vehicle crew 10 leading vehicle 12 following vehicles 12 include a driving support system 16 driving each vehicle 12 in the vehicle convoy 10 controls.

A vehicle 12 with a driving support system 16 is exemplary in 3 shown. Even if the vehicle 12 in 3 shown as a car, are the principles of the driving support system 16 and its design readily transferable to other types of vehicles. The Embodiments relating to the vehicle 12 of the 3 apply to all vehicles considered here 12 and vice versa.

The driving support system 16 includes in this embodiment, two front, first ultrasonic sensors 18 that relate to one direction of travel 20 on a front side 22 of the vehicle 12 attached, and two rear, second ultrasonic sensors 24 that in terms of the direction of travel 20 at a rear end 26 of the vehicle 12 are attached. The first and second ultrasonic sensors 18 . 24 are at the first and second vehicles 12 installed at a height of about one meter above ground level. In this embodiment, the first vehicle 12 a following vehicle 12 , and the second vehicle 12 is a preceding vehicle 12 ,

The driving support system 16 further comprises a control unit 28 via a communication bus 30 with the first and second ultrasonic sensors 18 . 24 connected is. The first and second ultrasonic sensors 18 . 24 Here are exemplary at a height of about 1.25 meters above ground level at the respective vehicle 12 appropriate.

The driving support system 16 is executed, distances 32 between a preceding vehicle 12 and a subsequent vehicle 12 to monitor as part of a distance control. This allows the vehicles 12 the vehicle crew 10 together a method for distance control between two vehicles 12 perform as described in detail below. The method is used here in connection with driving in a vehicle convoy 10 described.

The following is a method for distance control between two vehicles 12 for driving in the vehicle convoy 10 with reference to 4 described. The method additionally includes a distance correction based on the distance control. The method is described with additional reference to 2 . 5 and 6 described. Also, individual process steps may be performed in a different order from that specified herein or simultaneously, as will be apparent to those skilled in the art.

The procedure starts here in step S100 with a transmission of first ultrasonic signals 34 from the first, subsequent vehicle 12 , The first ultrasonic signals 34 are from exactly one of the first ultrasonic sensors 18 on the front side 22 of the first vehicle 12 sending out. The first ultrasonic signals 34 are emitted here independently of received ultrasound signals, since the received takes place independently in a subsequent step.

The first ultrasonic signal 34 is encoded before sending, here with a BPSK code 0 , There are successive first ultrasonic signals 34 coded differently to these first ultrasonic signals 34 to identify and distinguish by coding.

The other first ultrasonic sensor 18 of the first vehicle 12 is during the transmission of the first ultrasonic signal 34 passive for receiving ultrasonic signals. Immediately after the transmission of the first ultrasonic signal 34 The first ultrasonic sensor also changes 18 in a passive mode until it returns a first ultrasonic signal 34 sending out.

The time of transmission of the respective first ultrasonic signal 34 is recorded.

In step S110 becomes that of the first ultrasonic sensor 18 of the first vehicle 12 emitted first ultrasonic signal 34 from the second ultrasonic sensors 24 at the rear end 26 of the second, preceding vehicle 12 receive. In this case, a beginning of the respective first ultrasonic signal 34 used as a so-called trigger. The first ultrasonic signal 34 is decoded with BPSK code 0 , If the received first ultrasonic signal 34 can not be correctly decoded, the received first ultrasonic signal 34 discarded. Upon receipt of the first ultrasonic signal 34 becomes a trigger on the received first ultrasonic signal 34 triggered the time of receipt of the first ultrasonic signal 34 indicates.

In step S120 sends one of the second ultrasonic sensors 24 of the second vehicle 12 a second ultrasonic signal 36 with a predetermined delay to the received first ultrasonic signal 34 , The other second ultrasonic sensors 24 of the second vehicle 12 are passive for receiving first ultrasonic signals 34 , The emission of the second ultrasonic signals 36 is thus independent of the reception of the first ultrasonic signals 34 , The delay is for all vehicles 12 given globally and is here exemplarily 5 ms to the trigger when receiving the first ultrasonic signal 34 ,

The second ultrasonic signal 36 is encoded before sending, here with a BPSK code 1 , This is the second ultrasonic signal 36 depending on the coding of the previously received first ultrasonic signal 34 encodes to the second ultrasonic signal 36 in response to the corresponding first ultrasonic signal 34 to identify. The associated first and second ultrasonic signals 34 . 36 contain an identical identification.

In step S130 becomes that of the second ultrasonic sensor 24 of the second vehicle 12 emitted second ultrasonic signal 36 from one of the first ultrasonic sensors 18 on the front side 22 of the first vehicle 12 receive. In this case, a beginning of the second ultrasonic signal 36 used as a trigger. The second ultrasonic signal 36 is decoded with BPSK code 1 , If the received second ultrasonic signal 36 can not be correctly decoded, the received second ultrasonic signal 36 discarded. When decoding, the identification of the second ultrasonic signal 36 determined.

Upon receipt of the second ultrasonic signal 36 becomes a trigger on the received second ultrasonic signal 36 triggered the timing of the reception of the second ultrasonic signal 36 indicates.

A signal path from the emission of the first ultrasonic signal 34 in step S100 until receiving the second ultrasonic signal 36 in step S130 is in 6 shown.

In step S140 becomes a time difference between the emission of the first ultrasonic signal 34 and receiving the second ultrasonic signal 36 through the first vehicle 12 certainly. This is in the control unit 28 of the second vehicle 12 carried out. In this case, starting from the identification of the second ultrasonic signal 36 the time of transmission of the associated first ultrasonic signal 34 certainly.

step S150 relates to receiving echoes 38 that of the first vehicle 12 emitted first ultrasonic signals 34 , The reception of the echoes 38 starting from the first ultrasonic signals 34 is in 5 shown.

A beginning of the echo 38 is used as a trigger. The echo 36 is decoded with BPSK code 0 in accordance with the coding of the first ultrasonic signal 34 , If the received echo 38 of the first ultrasonic signal 34 can not be correctly decoded, the received echo 38 discarded. When receiving the echo 38 of the first ultrasonic signal 34 will trigger on the received echo 38 triggered the timing of the reception of the echo 38 of the first ultrasonic signal 34 indicates.

The steps S130 and S150 are basically identical and differ only in the further processing of the received signal. Depending on the coding of the received signal with BPSK code 0 or BPSK code 1 can be distinguished, whether it is an echo 38 of the first ultrasonic signal 34 or a second ultrasonic signal 36 , Therefore, receiving echoes 38 of the first ultrasonic signal 34 and the second ultrasonic signal 36 be carried out together.

In step S160 becomes the distance 32 between the first and second vehicles 12 through the first vehicle 12 certainly. The distance 32 is initially based on the in step S140 determined time difference minus the delay determined. The distance 32 Thus, it results from the (time difference - delay) divided by two times the sound velocity in air, which at standard conditions 343 m / s is.

In addition, when in step S150 an echo 38 of the first ultrasonic signal 34 was received, the distance 32 based on a time difference between the emission of the first ultrasonic signal 34 and receiving the echo 38 carried out. The distance 32 This results from the time difference divided by two multiplied by the speed of sound in air.

The distance 32 can be determined independently, both mathematically and temporally. At short intervals 32 in a reception area of the echoes 38 of the first ultrasonic signal 34 can be a redundant determination of the distance 32 between the vehicles 12 respectively. For larger distances, only the time difference is based on the received second ultrasonic signal 36 as a basis for determining the distance 32 ,

In step S170 becomes the distance 32 between the first and second vehicles 12 from the first, subsequent vehicle 12 to the second, preceding vehicle 12 via a communication connection 40 transfer. The communication connection 40 is as a bi-directional communication link 40 executed.

In step S180 becomes a speed of the first and second vehicles 12 from the respective vehicle 12 determined. For example, the speed is based on odometry data of the respective vehicle 12 or satellite position data, such as GPS, Galileo, Glonass, Beidou. step S180 can be done at any time. step S180 is preferably repeated at a predetermined interval to always maintain an actual speed of the vehicle 12 to know.

In step S190 becomes the distance 32 between the first and the second vehicle 12 based on the determined distance 32 customized. This concerns a countermeasure to change the distance 12 between the two vehicles 12 ,

The distance 32 is first with a given distance 32 compared to distance control to deviations of the distance 32 to the predetermined distance 32 to investigate. In particular, falls below a minimum distance between the two vehicles 12 controlled. Also, for distance control based on temporally consecutive distance determinations, a change in distance becomes 32 between the two cars 12 determined dynamically. This is done in the first and second vehicles 12 independently.

The adjustment of the distance 32 is by delaying and / or accelerating each of the two vehicles 12 carried out together. This includes an emergency braking of the following vehicle, for example when the distance control of the distance 32 between the two vehicles 12 falls below a minimum distance, depending on the determined speed.

A control of the distance 32 as a countermeasure based on the distance control is by the first vehicle 12 and the second vehicle 12 done in combination. Accordingly, with a reduction of the distance 32 between the vehicles 12 the preceding vehicle 12 accelerate, and the subsequent vehicle 12 delayed. The same applies vice versa with an increase in the distance 32 ,

In addition, the leading vehicle leads 12 the vehicle crew 10 with its environmental sensors in an in 1 illustrated detection area 42 a detection of potential hazards for the vehicle crew 10 by. When a hazard is detected, the driving vehicle starts 12 a delay of the entire vehicle convoy 10 by the driving vehicle 12 a braking process starts and additionally via the communication connection 40 a corresponding signal to all following vehicles 12 sends, so that they also delay. The deceleration takes place with the same intensity, the distance 32 between the vehicles 12 the vehicle crew 10 to hold constant during deceleration.

LIST OF REFERENCE NUMBERS

10

Motorcade

12

vehicle

14

roadway

16

Driving assistance system

18

first ultrasonic sensor

20

direction of travel

22

front

24

second ultrasonic sensor

26

rear end

28

control unit

30

communication

32

distance

34

first ultrasonic signal

36

second ultrasonic signal

38

echo

40

communication link

42

detection range

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 102015211117 A1 [0006]
• DE 102015213888 B4 [0007]
• DE 102016110001 A1 [0009]
• EP 1788749 B1 [0010]
• US 6965829 B2 [0011]

Claims (14)

Method for controlling the distance between two vehicles (12), in particular for driving in a column (10), comprising the following steps: Transmitting first ultrasonic signals (34) from a first vehicle (12), Receiving the first ultrasonic signals (34) emitted by the first vehicle (12) with a second vehicle (12), Sending a second ultrasound signal (36) from the second vehicle (12) at a predetermined delay to each received first ultrasound signal (34), Receiving the second ultrasonic signals (36) emitted by the second vehicle (12) with the first vehicle (12), Determining a time difference between the transmission of the first ultrasonic signal (34) and the reception of the second ultrasonic signal (36) by the first vehicle (12), and Determining a distance (32) between the first and second vehicles (12) based on the time difference minus the deceleration by the first vehicle (12). Method according to Claim 1 characterized in that the first vehicle (12) is a preceding vehicle (12), the second vehicle (12) is a subsequent vehicle (12), and the step of determining a distance between the first and second vehicles (12) the preceding vehicle (12) takes place. Method according to Claim 1 characterized in that the first vehicle (12) is a following vehicle (12), the second vehicle (12) is a preceding vehicle (12), and the step of determining a distance between the first and second vehicles (12) the following vehicle (12) takes place. Method according to one of the preceding claims, characterized in that the method comprises an additional step for transmitting the distance (32) between the first and second vehicle (12) from the first vehicle (12) to the second vehicle (12) via a communication link ( 40). Method according to one of the preceding claims, characterized in that the method comprises a step for receiving a speed of the first and / or the second vehicle (12). Method according to one of the preceding claims, characterized in that the method comprises an additional step for focusing the first ultrasound signals (34) emitted by the first vehicle (12) and an additional step for focusing the second ultrasound signals (12) emitted by the second vehicle (12). 36). Method according to one of the preceding claims, characterized in that the method comprises an additional step for attaching the ultrasonic sensor (18, 24) to the first and / or second vehicle (12) at a height of at least 80 cm above a ground level, preferably at least one meter above ground level, more preferably at least 1.25 meters above ground level. Method according to one of the preceding claims, characterized in that the method comprises an additional step for adjusting a distance (32) between the first and the second vehicle (12) based on the determined distance (32). Method according to one of the preceding claims, characterized in that the step of transmitting first and second ultrasound signals (34, 36) from the first and second vehicle (12), respectively, emanates coded first and second ultrasound signals (34, 36). includes. Method according to the preceding Claim 9 characterized in that the step of transmitting encoded first and second ultrasound signals (34, 36), respectively, comprises emitting the first and second ultrasound signals (34, 36) with a respective first and second code, respectively. Method according to one of the preceding claims, characterized in that the method comprises an additional step for receiving echoes (38) of the first ultrasonic signals (34) emitted by the first vehicle (12). Method according to one of the preceding claims, characterized in that the method comprises an additional step for emitting third ultrasound signals from the second vehicle (12) and receiving echoes (38) of the third ultrasound signals emitted by the second vehicle (12). Method according to one of the preceding claims, characterized in that the step of emitting first and second ultrasound signals (34, 36) from the first and second vehicle (12), respectively, sends out Ultrasonic signals (34, 36) having a modulated information signal, and the step of receiving the first and second ultrasonic signals (34, 36) with a second and first vehicle (12), respectively, demodulating the ultrasonic signals (34, 36) and receiving of the information signal. Vehicle convoy (10) having a plurality of vehicles (12), wherein the vehicles (12) of the vehicle convoy (10) are designed, the method according to one of the preceding Claims 1 to 13 perform.

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