RU2088951C1 - Method for selection of signals from objects closing with motor vehicle and device for its realization - Google Patents

Abstract

FIELD: radio engineering. SUBSTANCE: invention is intended for use in gears preventing collision of motor vehicles. It consists of selection of signals from objects (called dangerous) for meeting with which there remains time t_b determined beforehand. This is achieved with the use of signal selection from dangerous object in each range interval (in each range selector) by means of corresponding selection of signals from dangerous objects, i.e. by suppression of signals from all objects except those which closing speed (Doppler frequency range) is determined by range of distance for which selector is set and specified time to meeting with subsequent transmission of selected signals for processing in OR circuit. EFFECT: improved reliability and increased functional efficiency of the device. 3 dwg

Description

The invention relates to the field of electronic equipment of vehicles (TS) and is intended for the selection of radar signals of approaching objects, until a meeting (departure or collision) with which remains a predetermined time t _in . Signals from these objects (hereinafter referred to as hazardous objects) are used in collision avoidance radars (let's call these radars as automobile radars) to determine the danger of collision with these objects and take timely measures.

 A known method and device for preventing collisions of vehicles [1] including the generation, modulation, radiation and reception of electromagnetic (infrared) vibrations reflected from the object, their amplification, demodulation, determining the distance to the object and the relative speed of convergence with it, calculating the time before a collision with the object , the definition and analysis of conditions that determine the effectiveness of braking, the calculation of the time and sequence of inclusion of braking devices, alarm and safety.

 The considered analogue has the disadvantage that they first detect the signals of all objects, i.e. in the entire range of approach speeds at each range, and only after that calculate the time before meeting with the object. This can lead to errors in determining (identifying) an object as dangerous and complicates the equipment.

A known method and device of pulse-Doppler signal processing, which allows to determine the range and speed of approach of all objects located in the radar coverage area (and therefore, calculate the time before meeting each of them) [2] The method consists in the fact that the entire interval of working ranges are broken using range selectors into ranges (channels) of the range ΔD _i , in each of which Doppler filtering of signals is carried out in the entire range of approach speeds.

 In FIG. 1 shows a functional diagram corresponding to the method of the device.

The device includes an antenna unit with a coherent transceiver 1, range selectors 2 2 _i , center or sideband filters (FTP) 3 3 _i , mixers 4 4 _i , local oscillator 5, Doppler filter banks 6 6 _i , amplitude detectors 7 7 _i , threshold devices (detectors) 8 8 _i , an indicator of all detected objects 9, allowing selection (selection) of dangerous objects.

), которому соответствует поле параметров сигнала задержка доплеровская частота (f). Только после обнаружения каждого объекта возможны расчет времени до встречи с ним и отбор сигналов опасных объектов.However, these known method and device have the same disadvantages, because they detect signals from all objects that are within the range of action and in the entire possible range of approximation speeds, i.e. signals from all objects located in a given field of object parameters range-approach speed are subject to detection (D,

), which corresponds to the signal parameter field delay Doppler frequency (f). Only after the detection of each object is it possible to calculate the time before meeting it and select signals from hazardous objects.

The objective of the invention is the elimination of errors in the selection of signals of dangerous objects among the set of signals of all objects (we call this selection by the criterion t _in ) while simplifying the equipment.

The solution of this problem is achieved by the fact that in the method of pulse-Doppler selection of objects, including generation, emission and reception of a coherent signal, range selection, filtering of the central or sideband, heterodyning, detection and detection, selection of signals of dangerous objects is provided before the detection of signals, for whereupon the signals are selected along the line passing from the origin of the field of the delay-frequency signal parameter range (range-approach speed) at an angle α arctg t _in (Fig. 3), followed by by detecting signals and transmitting them to further processing schemes. This ensures that only dangerous objects are detected, and signals from other objects are not processed at all, they are suppressed.

,
где λ длина волны зондирующего сигнала, и среднюю частоту f_ср.i, смещенную на величину Df_i относительно средней частоты предыдущего по номеру селектора сигналов опасных объектов, т.е.For the device implementing the proposed method, this task is achieved in that in a pulse-Doppler radar containing an antenna unit with a coherent transceiver and series-connected range selectors, central or side-band filters, mixers, the second inputs of which are connected to the local oscillator output , a local oscillator common to all range channels, amplitude detectors, and threshold devices are included in each ith range channel between the mixer and the detector of signal selectors of dangerous objects, and After the threshold devices, an OR circuit is enabled, from the output of which the signals of dangerous objects are transmitted for further processing, and the ith signal selector of dangerous objects has a passband Df _i defined by formula 1

,
where λ is the wavelength of the probe signal, and the average frequency f _cf.i , shifted by the value of Df _i relative to the average frequency of the previous signal number of hazardous objects, i.e.

,
имея ввиду, что
f_ср.i=0=0

f₀ частота на входе селектора сигналов опасных объектов, соответствующая нулевому доплеровскому приращению;
ΔD_i=1 диапазон скоростей сближения с объектами, находящимися в первом (i= 1) диапазоне дальностей ΔD_i=1, время до встречи с которыми составляет t_в с.

,
bearing in mind that
f _{cf.i = 0} = 0

f _{0 the} frequency at the input of the signal selector of hazardous objects corresponding to zero Doppler increment;
ΔD _{i = 1} range of speeds of approach to objects located in the first (i = 1) range of distances ΔD _{i = 1} , the time before meeting which is t _in s.

2 На фиг. 2 представлена одна из возможных функциональных схем устройства, осуществляющего отбор сигналов от объектов, сближающихся с транспортным средством.Δf _{i = 1} range of Doppler frequencies corresponding to the range of approach speeds

2 in FIG. 2 shows one of the possible functional diagrams of a device that selects signals from objects approaching a vehicle.

The device contains an antenna with a coherent transceiver 1, range selectors 2 2 _i , center or sideband filters (FCBP) 3 3 _i , mixers 4 4 _i , a local oscillator common to all range channels 5, signal selectors of dangerous objects 6 6 _i , amplitude detectors 7 7 _i , threshold devices 8 8 _i , OR circuit 9, the output of which is connected to the input of the further processing circuit.

. Если количество интервалов дальности n, то общее число элементов матрицы в прототипе должно быть n². В АРЛС достаточно иметь n элементов, т.к. обнаруживать нужно только опасные объекты, до встречи с которыми осталось t_в с, т.е. объекты, удовлетворяющие условию

.In FIG. 3 shows the field of parameters of objects range-speed of approach in the form of a matrix of elements

. If the number of range intervals is n, then the total number of matrix elements in the prototype should be n ² . In ARLS, it is enough to have n elements, because only dangerous objects must be detected, before which t _in s are left, i.e. objects satisfying the condition

.

This means that in the parameter field the matrix elements corresponding to hazardous objects lie on a straight line having an inclination angle αarctg t _в . Therefore, the remaining components of the spectrum of Doppler increments of the signal frequency must be suppressed, which is what the hazardous objects selector does. In each hazard signal selector, a comb consisting of K filters and overlapping the band Df _{i can be used} . In this case, the resolution and accuracy of the approach velocity measurements will increase by K times, i.e. requirements for resolution (accuracy) in range and speed can be met independently.

 The possibility of implementing the proposed method and device is not in doubt, because the signal selectors of hazardous objects with a frequency shift from channel to channel can be realized both by appropriate filter settings and by creating a grid of heterodyning frequencies. The implementation of the OR scheme is publicly available.

As a result of the use of the invention, errors are eliminated in the determination of dangerous objects associated with calculating the time before meeting t _in all objects according to their measured ranges and speeds of approach The equipment is greatly simplified.

Claims (1)

A method for selecting signals from objects approaching a vehicle, including generating, emitting, receiving, converting and amplifying a pulsed coherent signal, ranging in range, filtering, second frequency conversion, detection and detection, characterized in that prior to detection from the signals of all objects located in the working ranges of the range and speed of approach, they select signals only from those objects until which they meet the specified time until the meeting t _in s, where t _{at a} time sufficient To evade the vehicle from colliding with the object, if the subsequent analysis of the detected signals indicates a danger of this, for this purpose, in each i-th range channel, after the second frequency conversion, all signals except the reflection from the object whose proximity speed is suppressed using the frequency selector and, consequently, the Doppler increment of the signal frequency, corresponds to a predetermined remaining time before meeting t _in , detected signals are detected.

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