EP2118421A2

EP2118421A2 - Radar sensor for controlling automatic doors, automatic door comprising said radar sensor, and method for operating said door

Info

Publication number: EP2118421A2
Application number: EP08701349A
Authority: EP
Inventors: Norbert Fend; Walter Etterlin
Original assignee: 4 Tec AG
Current assignee: 4 Tec AG
Priority date: 2007-01-12
Filing date: 2008-01-09
Publication date: 2009-11-18
Also published as: WO2008084058A3; WO2008084058A2

Abstract

The invention relates to a radar sensor (20, 21) for controlling automatic doors (10). Said radar sensor comprises a radar module transmitting a radar signal and receiving reflected signals, and an associated control, the radar sensor (20, 21) having a first detection range (22, 24) in which it detects moving objects (26) by evaluating Doppler signals. The aim of the invention is to simplify and improve a door control of the aforementioned type. For this purpose, the radar sensor (20, 21) has a second detection range (23, 25) in which it detects the distance to objects present in said area.

Description

DESCRIPTION

RADAR SENSOR FOR THE CONTROL OF AUTOMATIC DOORS,

AUTOMATIC DOOR WITH SUCH A RADAR SENSOR, AND

METHOD FOR OPERATING SUCH A DOOR

TECHNICAL AREA

The present invention relates to the field of automatic doors. It relates to a radar sensor for the control of automatic doors, an automatic door with such a radar sensor, and a method for operating such a door.

The term "automatic doors" in the present application, all types of doors, gates, elevator doors, bus and train doors, telescopic doors and the like. Understood, in which closing and opening movements take place in different directions, especially horizontally or vertically. With the introduction of the new standard DIN 18650, door controls belong to the machines and must meet the corresponding safety requirements.

STATE OF THE ART

Automatic doors, which are equipped with automatically opening and closing door leaves (rotary or sliding sashes), are used in a wide variety of applications. In such doors, depending on the function, it must be ensured that the door opens when a person or other object approaches the door in the direction of passage from one or both sides. On the other hand, for reasons of safety, it must be ensured that the opened door only closes when there is no obstacle in the movement range of the door leaves. Usually, different sensors are used for these two functions: the one for the automatic one

Opening the door competent sensor works as a motion detector, which detects an object to be moved to the door and triggers a corresponding opening command of the door control. The sensor responsible for monitoring the passage area of the door only detects the (static) presence of an object in the closing area.

A known from the prior art, exemplary solution with two different sensors is shown in simplified form in Fig. 1: The automatic door 10 'of FIG. 1 is designed as a symmetrical sliding door, in a door frame 11, two door leaves 12 and 13 horizontally between an opening position and a closing position are movable. To control the door movement sensors 15 and 16 are arranged on both sides of the door frame above the passage area D in the middle, which are connected to a central controller 14 (dotted connection lines). For monitoring the passage area D two (horizontal) light barriers 17 and 18 are provided at different heights above the ground, which are also connected to the controller 14. Is automatically located initiated closure process a person or another object in the passage area D, the closing process is stopped and reversed, ie the door 10 'opens again. If an object in the passage area D is detected before the beginning of the closing process, the closing process is suspended. As motion sensors 15, 16 have become increasingly in recent times

Radar sensors enforced, the structure and function is described for example in the document DE-A1 -100 12 115.

From DE-A1-102 60 109 a sliding door system is known, in each case two sensors are provided, one of which is designed to detect an approach to the door and the other for detecting obstacles in the range of movement of the sliding sash. The motion sensor here is a passive infrared sensor, the obstacle sensor an active infrared sensor.

From EP-A2-1 484 467 a door control with a presence sensor is known, which is preferably designed as a radar sensor and measures distances that are compared with previously learned results. Nothing is disclosed about the control of the door by moving objects.

From EP-A1-1 640 742 a door control is known, in which a radar sensor for the near range is combined with a separate presence sensor with FMCW radar, which directly monitors the passage area of the door.

From DE-A1-198 17 396 a method for monitoring of input areas is known in which the characteristic of the response signal of a radar sensor is evaluated to monitor the number and type of persons or objects located in the entrance area.

A disadvantage of all known methods and devices, the complexity of the arrangements and the incomplete monitoring and safeguarding of the operation. PRESENTATION OF THE INVENTION

It is an object of the invention to provide a radar sensor, with which all control and monitoring function for an automatic door can be realized in a simple manner without restrictions, and to provide an automatic door with such a sensor and a method for their operation.

The object is solved by the totality of the features of claims 1, 10 and 15. The essence of the invention is to use a single radar sensor which, in addition to a first detection area in which it detects objects moved by evaluation of Doppler signals, has a second detection area in which it detects the distance to objects present in this area.

According to one embodiment of the invention, the two differ

Detection areas from each other in position and shape, in particular, the second detection area is transverse to the emission direction substantially adjacent to the first detection area.

A preferred embodiment of the invention is characterized in that the radar sensor has a radiation characteristic with a main lobe and a first side lobe, and that the first side lobe defines the first detection area and the main lobe defines the second detection area.

Preferably, the radar module is operated in the frequency-modulated continuous wave mode (FMCW), wherein the radar module comprises a voltage-controlled oscillator, and a varactor is provided for controlling the voltage-controlled oscillator.

Another embodiment is characterized in that the radar module for the evaluation of the received signals has a quadrature channel and an input signal. Phase channel having a corresponding mixing device, and that the output signals of the two channels are evaluated by means of a controller provided in the microprocessor with respect to the first and second detection range.

A further development is characterized in that the output signals of the two channels for evaluating the Doppler signals in the first detection area are amplified in a first amplifier which is arranged between the radar module and the microprocessor, and in that the output signals of the two channels for the evaluation of the distance measurement in the second detection area be amplified in a second amplifier, which is arranged between the radar module and the microprocessor.

Preferably, a common third amplifier with controllable variable amplification is arranged between the radar module and the first and second amplifiers for preamplifying the output signals of the two channels.

A preferred embodiment of the inventive automatic door is characterized in that the at least one radar sensor is mounted on a door frame above the passage area laterally.

In particular, a radar sensor can be arranged in each case on both sides of the door frame, wherein the detection ranges of both radar sensors overlap in the passage area of the door.

Another preferred embodiment of the automatic door according to the invention is characterized in that the second detection area in the passage direction to a distance of several decimeters, in particular 20-30 cm, extends from the door, and that the first detection area in the passage direction to a distance from several meters, especially 1, 5-2.5 meters, from the door. In principle, the automatic door can be designed as a hinged door, revolving door or sliding door. Preferably, the door is designed as a sliding door and has two opposite sliding door leaves.

An embodiment of the method according to the invention is characterized in that the distance measurements in the second detection area are carried out continuously, and that the respective measurement result is compared with a stored first reference value which has previously been determined for the free passage area with the door completely open.

A refinement is characterized in that the distance measurements in the second detection area are continued when the door closes and is in different intermediate positions, and that the measurement results are compared with stored second reference values previously for the free passage area at the respective intermediate position of the door have been determined.

BRIEF EXPLANATION OF THE FIGURES

The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. Show it

Fig. 1 shows an automatic door with various sensors according to the prior art;

Fig. 2 in side view a highly schematic representation of a

Door with radar sensors according to an embodiment of the invention;

Fig. 3 in plan view from above the door of Fig. 2 in the closed

(Fig. 3 (a)) and in the opened state (Fig. 3 (b)); Fig. 4 seen the two detection areas of a door according to the invention with only one sensor in the passage direction;

Fig. 5 seen the two detection areas of Figure 4 from the side.

Fig. 6 seen the two detection areas of Figure 4 from above.

Fig. 7 shows the main and side lobes of a radar sensor according to the invention;

8 shows the highly simplified block diagram of a radar sensor according to an embodiment of the invention; and

Fig. 9 in several sub-figures different phases when closing a sliding door monitored according to the invention.

WAYS FOR CARRYING OUT THE INVENTION

The basic idea of the present invention is to cover the door opening (dynamic measurement) with a special radar sensor and additionally the function of the light barrier in FIG. 1 (static presence measurement).

According to FIG. 2, a radar sensor 20 or 21 is used on one or both sides of the door frame 11 to monitor the entire space in front of, in and behind an automatic door 10 from the top to the bottom 19. Each radar sensor 20, 21 has a first detection area 22, 24 and a second detection area 23, 25, respectively. In the first detection area 22, 24, a dynamic measurement is performed, ie, moving objects such as a person 26 approaching the door 10 are detected and detected the control of the door 10 is common. This measurement is carried out according to the known Doppler principle. The first Detection area 22, 24 extends from the door to a distance from the door 10 of about 1.5 to 2.5 m.

In the second detection range 23, 25, according to the FMCW method (frequency-modulated continuous wave mode), one or more time-staggered frequency sweeps carry out a distance measurement on objects located in the passage region D of the opened door, which constitute an obstacle to the closing of the door 10. For this purpose, the result of the current distance measurement is compared with stored results which were obtained with the door open without hindrance in an earlier learning step. As soon as the results compared differ significantly, the closing process is stopped or a closing process is not initiated.

Basically, static and dynamic measurements can be done in both

Detection areas 22, 24 and 23, 25 are carried out simultaneously at any time by performing sweeps at certain time intervals for the static measurement and dynamic measurements according to the Doppler principle between the sweeps. However, it is expedient to measure with the door closed only in the first detection areas 22, 24 (FIG. 3 (a)) and the measurements in the second detection areas 23, 25, which detect the passage area D of the door 10, according to FIG. to begin only when the door 10 has opened automatically (Figure 3 (b)).

The static measurement in the second detection area 25 can according to FIG. 9 with

Advantage also be carried out during the closing of the door. For this purpose, the closing process is subdivided into steps with different opening widths (eg FIGS. 9 (a) - (c)). For each step, a reference signal of the undisturbed door characteristic of the opening width is stored in the memory of the radar sensor, with which the current measurement is compared in each case. If a disturbing object enters the passage area D of the door during the closing process, deviates from the measured signal from the stored reference signal and the closing process is aborted and reversed.

In the passage direction (FIG. 4) and seen from the side (FIG. 5), the two detection regions 24, 25 have a simplified triangular cross section profile, while the cross section is semicircular (first detection region 24) when viewed from above (FIG. has the shape of a narrow strip (second detection area 25).

The two detection areas 24, 25 are defined by the side lobe 46 (first detection area 24) and the main lobe 47 (second detection area 25) in the radiation characteristic of the radar sensor 20, 21, wherein the strong main lobe 47 for increased sensitivity in the (static Distance measurement in the passage area D stands.- The two detection areas 24, 25 can be changed in their extent by changing the gain of an amplifier (35 in Fig. 8).

The construction of the radar sensor 21 is shown in a simplified block diagram in FIG. 8. Essential components of the radar sensor 21 are the actual radar module 27, which is responsible for transmitting and receiving the radar signals, and a microprocessor 28, which controls and evaluates its various outputs 42, .., 45 outputs signals for further use in the door control.

The radar module 27 contains, inter alia, a feed 33, a voltage-controlled oscillator (VCO) 32, which preferably operates with a varactor, an enable circuit 31 for controlling the activity of the module, as well as an in-phase channel 30 and a quadrature channel 29, in FIG where the received signal is mixed with the frequency from the oscillator 32 in antiphase. The output signals of both channels 29, 30 are pre-amplified in a common amplifier 35 with a low-pass function and then supplied to separate amplifiers 36 and 37 with band-pass function. The common amplifier 35 has a from Microprocessor 28 controlled variable gain, which is switched when switching between static (sweep) and dynamic measurement (Doppler) and can be changed to change the extent of the detection ranges. Subsequent upper amplifier 36 amplifies the sweep signal generated by frequency modulation for the static

Distance measurement in the second detection area 23, 25, while the lower amplifier amplifies the Doppler signal for the dynamic measurement in the first detection area 22, 24. A radar signal evaluation block 40 is provided in the microprocessor 28 in which the radar signals from the amplifiers 36 and 37 are evaluated, in particular subjected to digital filtering and fast Fourier transformation.

The microprocessor 28 controls the oscillator 32 via a digital-to-analogue converter 38. For temperature monitoring, a temperature sensor (for example NTC) 34 is provided on the radar module 27, the signal of which reaches the microprocessor 28 via an amplifier 38. For storing various parameters, the microprocessor 28 is connected to a memory 41. Of the plurality of microprocessor 28 arranged outputs 42, ..., 45, the output 42 is provided in particular for the diagnosis of the radar sensor 21, the output 43 for the presence signal from the second detection range 23, 25, the output 44 for motion signals from the first detection area 22, 24, and the output 45 for display and control functions.

Overall, the invention provides the following characteristic features and advantages:

By FM modulation of the radar information about the objects lying in the detection area can be obtained. - Depending on the detection mode, the area to be examined in the

Distance to be selected. - This information is used as a reference image in a calibration

Calculator stored and continuously compared with the current detection. A functional failure, a pollution or a gradual one

Sensory loss can be recognized this way.

In addition, with the also present motion information can be distinguished whether it is human or immobile objects.

After a door opening, the static detection is activated, the door is kept open until the current detection matches the reference image and the detected targets do not have minimal movements. exhibit. - This safety function is also active during the following door closing, as the computer knows the reference pictures of the door closing and checks them constantly when closing.

The combined detection of objects or persons with the moving door leaves immediately leads to an alarm (and reversal of the door)

- The antenna diagram is shaped so that the energy is emitted mainly (in the main lobe) down to the largest

Sensitivity for static detection (frequency sweep).

This allows a radar sensor to monitor the hazardous area of the door during closure. In contrast to the one-dimensional beam of the light barrier, the whole volume is around the

Door leaf detected (Likewise, the static-sensitive active IR

Light sensors only detect the area in front of the door leaves).

The patch antennas of the radar module used can be excited so that the main lobe is inclined by about 10 ° in the door. This is a static detection in the entire danger zone of moving

Door leaves possible.

In addition, the same antenna has forward side lobes.

The gain of the analog channel (amplifier 35) can be switched during operation. Thus, these side lobes can be used frontally for dynamic detection. - Through this switching static and dynamic fields can be changed independently.

The sensor can provide an output for detection (opening pulse to the

Door) and a light barrier output that emulates the function of the light barrier.

With an optional CAN interface and an adapted door control further safety functions can be realized.

To meet the requirements of a sensor for escape and rescue doors, a self-monitoring of the computer and its memory can be provided. The function of the radar sensor can thus be checked completely over the entire amplifier chain.

With a single antenna, a dynamic and static function is realized. For the functions test, statics and dynamics, the received signals are amplified and evaluated differently. In a conventional radar sensor, however, is always trying to

Reflections of the door leaves are not within the detection range.

The present sensor uses the signals of the door wings around the

To evaluate information "door individually" or "door with person / object".

Two radar sensors can be used for the safe operation of the door. One is integrated on the side of the door in the automatic, and one is mounted on the other side in a housing.

The two detection fields (detection areas) also contain the

Closing area of the door, so that the door movement and static

Objects in this area can be measured. - Due to the resulting superposition of the two detection fields

(Detection areas) results in the closing area a double

Safety.

The radar sensors are monitored by a constantly running test procedure. - The standard DIN 18650 (and AUTSCHR) can already with only one

Radar sensor of the inventive type are met, with a inside Radar sensor according to the invention and outside a standard sensor is mounted.

LIST OF REFERENCE NUMBERS

10.10 'automatic door (e.g., sliding door)

1 1 door frame

12.13 door leaf

14 control

15.16 motion sensor (e.g., radar)

17.18 photocell

19 floor

20.21 radar sensor

22, .., 25 detection range

26 person

27 radar module

28 microprocessor

29 quadrature channel

30 in-phase channel

31 enable circuit

32 Voltage Controlled Oscillator (VCO)

33 supply

34 temperature sensors (NTC)

35, ... 38 amplifiers

39 Digital-to-Analog Wandier (DAC)

40 radar signal evaluation block

41 memory

42, .., 45 output

46 sidelobe

47 main club

D Passage area (door)

Claims

A radar sensor (20, 21) for controlling automatic doors (10) having a radar signal emitting and receiving reflection signals

Radar module (27) and an associated controller (28; 34, .., 45), wherein the radar sensor (20, 21) has a first detection area (22, 24) in which it detects by moving Doppler signals moving objects (26) , characterized in that the radar sensor (20, 21) has a second detection area (23, 25) in which it detects the distance to objects present in this area.

2. Radar sensor according to claim 1, characterized in that the two detection areas (22, 24 or 23, 25) differ from each other in position and shape.

3. Radar sensor according to claim 2, characterized in that the second detection area (23, 25) transversely to the emission direction substantially adjacent to the first detection area (22, 24).

4. Radar sensor according to one of claims 1 to 3, characterized in that the radar sensor (20, 21) has an antenna with a radiation characteristic with a main lobe (47) and a first side lobe (46), and that the first side lobe (46). defines the first detection area (22, 24) and the main lobe (47) defines the second detection area (23, 25).

5. Radar sensor according to claim 4, characterized in that the antenna is a patch antenna.

6. Radar sensor according to one of claims 1 to 5, characterized in that the radar module (27) in the frequency-modulated continuous wave mode (FMCW) is operated.

7. Radar sensor according to claim 6, characterized in that the

Radar module (27) comprises a voltage controlled oscillator (32), and that for controlling the voltage controlled oscillator (32), a varactor is provided.

8. Radar sensor according to claim 6 or 7, characterized in that the radar module (27) for the evaluation of the received signals has a quadrature channel (29) and an in-phase channel (30) with a corresponding mixing device, and that the output signals of two channels (29, 30) by means of a in the controller (28; 34, .., 45) provided microprocessor (28) with respect to the first and second detection range (22, 24 or 23, 25) are evaluated.

9. Radar sensor according to claim 8, characterized in that the output signals of the two channels (29, 30) for evaluating the Doppler signals in the first detection range (22, 24) in a first amplifier (37) are amplified between the radar module (27). and the microprocessor (28) is arranged, and that the output signals of the two channels (29, 30) for evaluating the distance measurement in the second detection range (23, 25) in a second amplifier (36) are amplified between the radar module (27). and the microprocessor (28).

10. Radar sensor according to claim 9, characterized in that between the radar module and the first and second amplifiers (37 and 36) for preamplification of the output signals of the two channels (29, 30) a common third amplifier (35) arranged with controllable variable gain is.

11. Automatic door (10) with at least one radar sensor (20, 21) according to one of claims 1 to 10, which automatic door (10) has at least one door leaf (12, 13) in response to signals from the radar sensor (20 , 21) is automatically moved between a first position in which the door (10) is closed and a second position in which the door (10) is open, characterized in that the radar sensor (20, 21) on the Door (10) is arranged such that the first detection area (22, 24) covers a space in front of the door (10) space, and that the second detection area (23, 25) directly in the range of movement of the at least one door leaf (12 13) covering passage area (D) covers.

12. Automatic door according to claim 11, characterized in that the at least one radar sensor (20, 21) on a door frame (11) above the passage area (D) is mounted laterally.

13. Automatic door according to claim 12, characterized in that a radar sensor (20, 21) is arranged on both sides of the door frame (11), and in that the detection areas (22, 24 or 23, 25) of both radar sensors (20 , 21) in the passage area (D) of the door (10) overlap.

14. Automatic door according to one of claims 11 to 13, characterized in that the second detection area (23, 25) extends in the passage direction to a distance of several decimeters, in particular 20-30 cm, from the door (10), and that the first detection area (22, 24) extends in the passage direction up to a distance of several meters, in particular 1, 5-2.5 meters, from the door (10).

15. Automatic door according to one of claims 11 to 14, characterized in that the door (10) is designed as a sliding door and two oppositely displaceable door leaves (12, 13).

16. A method for operating an automatic door (10) according to any one of claims 11 to 15, characterized in that with the door (10) closed by the controller (28; 34, .., 45) only Doppler signals from the first detection area (22 , 24), and that the distance measurements in the second detection area (23, 25) are only performed when the door (10) is open.

17. The method according to claim 16, characterized in that the distance measurements in the second detection area (23, 25) are carried out continuously, and that the respective measurement result is compared with a stored first reference value previously for the free passage area (D) at fully open Door (10) has been determined.

18. The method according to claim 16 or 17, characterized in that the distance measurements in the second detection area (23, 25) are continued when the door (10) closes and is in different intermediate positions, and that the measured results are compared with stored second reference values are previously determined for the free passage area (D) at the respective intermediate position of the door (10).