Patent Application
20190169908
The present invention relates to a motorized door comprising a shutter for closing and opening an area. More specifically it relates to a motorized door comprising a series of sensors for detecting an accidental obstacle before it is in a position to actually impact with the shutter, and a controller configured for receiving signals from the sensors and for instantly stopping the closing motion of the door when an accidental obstacle is thus detected.
Motorized doors comprising a shutter are commonly used to shut off openings, particularly in warehouses, supermarkets, industrial halls, aircraft hangars, fire service equipment halls, or assembly halls. These shutters are often made up of large flexible tarpaulins the lateral edges of which comprising beads which slide in guiding rails situated on each side of the opening that is to be closed. Alternatively, the shutters can be made of rigid panels hinged to one another side by side or the shutter can be a rigid panel. Automatic doors are particularly useful when they are used to separate two spaces having different environmental conditions, such as temperature, relative humidity and the like, and more particularly to separate an indoor space from outdoor. Doors able to open and close at high speed are also known for these applications and are often referred to as “fast doors”.
One issue with motorized doors, particularly with fast doors due to their high closing speeds, is impacts with obstacles accidentally located within the closing trajectory of the shutter. Besides damaging the leading edge of the shutter and also disengaging the bead of the shutter lateral edges from the guiding rail, the obstacle itself can be damaged. Considering that such obstacle can be a person, the danger in case of an impact of injuring said person is quite high and must be reduced substantially. For this reason, strict norms have been imposed on motorized doors. For example, in order to comply with the European norm EN12453, the peak force of an impact with a body must not exceed the limit of 150 N during more than 5 s, and must not exceed the limit of 400 N during more than 0.75 s.
A number of safety precautions to prevent obstructing objects or persons located in the door opening from being damaged or injured when the door is closing have been proposed and implemented in the art.
Typically, the leading edges of motorized doors are equipped with damping elements, such as a lip made of a resilient material, or pneumatic absorbing pistons. For most doors, in particular fast doors, which have a high kinetic energy, such damping elements reduce the impact force in case of impact, but not sufficiently to meet the requirements of EN12453. Many doors are therefore additionally or alternatively provided with detection cells.
An accidental event detection cell can comprise contact detectors as disclosed for example in US2007/0261305. Alternatively, some detection cells are based on the comparison with a reference value of parameters such as the motor torque, motor energy consumption, or shutter closing speed, such as in U.S. Pat. No. 5,198,974. Such detection cells, however, identify the occurrence of an impact only after the leading edge has contacted the obstacle, which is of limited use for a person being hit by the leading edge of a closing shutter.
Many motorized doors have been developed comprising (a) contactless detection cells suitable for detecting the presence of an obstacle within the closing trajectory of a shutter before an impact occurs, and (b) a control system programmed for implementing a safety function aimed at managing the accidental presence of obstacles, in particular by stopping the door in its travel when it encounters one and moving it away from the obstacle in order to allow the removal thereof. With some control systems, when an accidental presence of an obstacle is detected, the direction of the motion is reversed to re-open the shutter.
Various types of such contactless detection cells are known in the art. For example, U.S. Pat. No. 7,034,686 discloses a proximity detector provided with an antenna, which triggers a command to stop and reverse the closure of the vertical door when the magnetic field created by the antenna is disturbed by a foreign object.
Another type of contactless detection known in the art are comprises the installation of a number of photoelectric barriers across the opening plane of the door as disclosed in U.S. Pat. No. 6,218,940. In this disclosure, the opening plane of the door is provided with what is referred to as a light curtain by means of a scanning light beam. When the light current is infringed, a safety function is activated and the door movement is reversed. A disadvantage of a light curtain is that it only senses obstacles in the plane of the opening of the door. The consequence is that the reversal of the movement of the door does not always take place promptly enough to avoid collision between upwardly projecting parts of the obstacle. For example, the tips of a forklift truck can infringe the light curtain and trigger the reversal of the movement of the door but if the door is not removed fast enough the forklift can still collide with the door.
Detection systems are generally positioned either on the moving shutter, generally at the leading edge of the shutter, or away from the shutter, for example above the proximal transverse edge of the shutter. Positioning a detection system at the leading edge of a moving shutter, such as described in Swedish Patent Application No. SE1551190-0, has the advantage that the relevance of a detected obstacle can be determined as a function of the actual position of the leading edge. For example, if the leading edge of a closing shutter is still close to its opening position, quite far away from a detected obstacle, the detection of said obstacle may not necessarily require the stopping of the shutter. On the other hand, if the obstacle is detected at the last moment when the leading edge is close to said obstacle, in view of the speed and inertia of the closing shutter, an impact may not be avoidable.
When a detection system is positioned away from the moving shutter, its signal is easier to control and analyze since the detection system is static. It can also scan a space ahead of the opening area, so that the relevance of an obstacle can be assessed before it comes within impact distance from the leading edge. Such static detection sensors are, however, disconnected from the instant position of the leading edge, and the detection of an obstacle can trigger the stopping of the shutter when the leading edge is actually at a position which represents no real threat of impact with said obstacle.
There remains a need in the art for a detection system and a control system applied to a motorized door, which can detect accidental obstacles and ensure that an impact can be prevented even when said obstacle reaches the opening area of the door only a very short time before an impact would occur. At the same time, unnecessary stoppings of the shutter movement can also be prevented.
The present invention is defined in the appended independent claims. Preferred embodiments are defined in the dependent claims.
In particular, the present invention concerns a motorized door for closing an area, the area being defined by a first and second lateral edges which extend parallel to a longitudinal axis, X1, by a proximal transverse edge extending parallel to a transverse axis, X2, normal to the longitudinal axis, X1, and a distal transverse edge, transverse to the longitudinal axis, X1, and wherein said axis X1 and X2 form a plane (X1, X2). The motorized door according to the invention comprises:
Advantageously, by mounting a sensor with an ultrasonic emitter/receiver unit on the first main surface of the shutter on or adjacent to said leading edge such that the central sensor axis of the sensor forms an opening angle γ1 measured along the plane (X1, X3) comprised between 5 and 70°, preferably between 5 and 40°, more preferably between 10 and 30°, most preferably between 15 and 25°. The maximum detectable distance along the X3 axis to the opening area for detecting an accidental obstacle is decreasing when the door is closing. In this way, when the door is almost closed, any obstacle sufficiently far away from the door (for example a car driving at a given distance from the door) will not disturb the closing of the door. In other words, if during the closing of the door an obstacle is located at a given distance of the opening, whether or not the controller will stop the movement of the closing door will depend on how much the door is already closed. Hence the detectable zone in front of the opening area is varying with the position of the leading edge.
Advantageously, by orienting the sensors at angle γ1 equal or larger than 5°, both obstacles located in the opening area as well as obstacles located further away from the opening area can be detected by the ultrasonic beam. Preferably, γ1 is comprised between 40° and 65°, preferably between 50° and 60°.
Advantageously, by continuously or sequentially monitoring the instantaneous distance, di(t), of any potential obstacle and by continuously or sequentially comparing these instantaneous distances, di(t), with a value of a threshold distance, dt(x1), a distinction can be made between an accidental obstacle and a non-accidental obstacle such as for example the floor or the lateral sides of the area.
In embodiments according to the invention, each ultrasonic emitter/receiver unit has each ultrasonic emitter/receiver unit (8.i) has a first sound pressure half-angle, β1, measured on a plane (X3i, 6.i) defined by the central sensor axis 6.i and an axis X3i parallel to axis X3, passing by the emitter/receiver unit (8.i), which is comprised between 15 and 45°, preferably between 20 and 35°, and wherein β1 is preferably greater than or equal to γ1 (i.e., β1≥γ1).
For example, said opening angle, γ1, and sound pressure half-angle, β1, can be such that,
In other embodiments, the motorized door according to the invention comprises a detector for determining the instantaneous distance, x1(t), of the leading edge to the distal transverse edge and wherein the detector is configured for communicating this instantaneous distance to the controller.
In a preferred embodiment, for each sensor the values of the opening angle, γ1, and of lateral opening angle, γ2, between the central sensor axis and the plane (X1, X2) measured on the plane (X2, X3), can be varied. The lateral opening angle, γ2, can preferably be varied between −45°≤γ2≤45°; said lateral opening angle, γ2, is more preferably comprised within 90°±5°.
The predetermined value of the threshold distance, dt(x1) of the sensors, can preferably be varied as a function of the value of the instantaneous distance, x1(t). For example, dt(x1)<x1(t)+Δx1, wherein Δx1 is the distance between the sensor and the leading edge measured along X1. In another example, dt(x1), decreases with decreasing value of x1(t); it preferably decreases linearly.
In a preferred embodiment of the present invention, the controller is configured for each sensor to continuously or sequentially compare the instantaneous distances, di(t), of said obstacle with a predetermined value of a threshold warning distance, dw(x1)>dt(x1), and to slow down the movement of the leading edge in the first direction and/or to emit a signal selected from a visual and/or acoustic signal, when the instantaneous distance of an obstacle from said sensor is equal to or lower than the threshold warning distance, dw(x1), but larger than the threshold distance, dt(x1), (i.e., when dt(x1)<di(t)≤dw(x1)). Sensors suitable for the present invention are characterized by a maximum detection range MR, which is preferably at least 2 m, more preferably at least 3 m
The controller may further be configured to reverse the movement of the leading edge into the second direction (α2) after having instantly stopped the movement thereof in the first direction (α1).
In embodiments according to the invention, each ultrasonic emitter/receiver unit (8.i) is defined by a second sound pressure half-angle, β2, measured on a plane comprising the central sensor axis (6.i) and an axis X2′(x1) parallel to the axis X2 and intersecting the central sensor axis. The second sound pressure half-angle, β2, is preferably comprised within 25° and 65°.
In preferred embodiments, the motorized door according to the invention comprises a second series of sensors (3.j, with j=1 to m), wherein m≥2, similar to the sensors of the first series and which are distributed on the second main surface of the shutter, along and on or adjacent to the leading edge. The sensors of the second series of sensors have a second opening angle, γ1′, measured on a plane (X1, X3) comprising X1, and normal to the plane (X1, X2). The controller is further configured to receive and treat signals from each of the m sensors of the second series in the same way as it treats the signals from the n sensors of the first series.
For a fuller understanding of the nature of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings in which:
As illustrated in
The shutter comprises a first and second main surfaces separated from one another by a thickness of the shutter. The shutter further comprises a leading edge 1L substantially parallel to the distal transverse edge 20D of the area. The motorized door comprises a motorized driving mechanism 5 suitable for moving the leading edge 1L of the shutter along the longitudinal axis, X1, between an open position, (x1,0), wherein the leading edge is adjacent to the proximal transverse edge and a closed position, (x1,1), wherein the leading edge contacts the distal transverse edge. The leading edge can move in a first direction α1 to close said area and in a second direction α2 to open said area (cf. arrows α1 & α2 in
The shutter can be a flexible shutter in the form of a flexible fabric or curtain, and, as shown in
In some embodiments, the deformable shutter comprises rigid panels hinged to one another parallel to the transverse axis, X2, and the motorized driving mechanism 5 drives the rotation of an axle about which the hinged panels rotate and change direction. For example, radial pins or teeth in the axle may cooperate with openings within the hinges between panels to ensure a slip-free movement of the deformable shutter. Alternatively, cables or chains can be used to drive the movement of the shutter.
In alternative embodiments, a third type of shutter in the form of a rigid panel is used. In these embodiments, the motorized driving mechanism 5 drives the rotation of an axle which moves the rigid shutter in the plane of the area in the first and second directions.
In case of a vertical area 20 as illustrated in
A motorized door according to the present invention comprises a first series of n sensors (3.i, with i=1 to n), wherein n≥2, distributed on the first main surface of the shutter, along the leading edge. The motorized door comprises a controller to receive signals from each of the n sensors and wherein the controller is configured to instantly stop the movement of the leading edge in the first direction α1 when an accidental obstacle is detected by any one of the sensors,
The present invention is characterized in that each sensor 3.i of the first series of n sensors comprises an ultrasonic emitter/receiver unit 8.i configured for emitting an ultrasonic beam along a central sensor axis 6.i. The sensors 3.i are mounted on the first main surface of the shutter on or adjacent to the leading edge 1L and oriented such that the central sensor axis 6.i forms an opening angle, γ1, with the plane (X1, X2) that is comprised between 5 and 70°. This opening angle γ1, as schematically illustrated in
The emitter/receiver unit 8.i is suitable for detecting and communicating to the controller, the presence within the ultrasonic beam of an obstacle and the instantaneous distance, di(t), of the obstacle to the corresponding sensor 3.i.
In some embodiments, the opening angle, γ1, is preferably comprised between 5 and 30°. In other embodiments, as will be illustrated below, γ1 can have a larger value and can be comprised between 40° and 65°, preferably between 50° and 60°.
An ultrasonic emitter/receiver unit 8.i is known to transmit a short burst of ultrasonic soundwave which is reflected by the presence of an obstacle. A controller then measures the time for the echo to return to the sensor and computes the distance from the sensor to the obstacle using the time-of-flight principle and applying the speed of sound in the medium. As the leading edge is moving—often at a high velocity—while the sensors emit and receive ultrasonic waves, the Doppler effect is also taken into account in order to determine the presence of an obstacle and also its possible motion and direction of such motion.
The controller according to the invention is configured to continuously or sequentially perform for each sensor 3.i the following steps:
In some embodiments, after detecting an accidental obstacle, the controller is configured to reverse the movement of the leading edge into the second direction α2 after having instantly stopped the movement thereof in the first direction α1.
The controller can either be a single controller used for all sensors of the series of n sensors or alternatively, each sensor can have its proper controller to control and read-out the signals of the sensor. If a single controller is used, a fast multiplexer can be used to switch between the sensors and control and read-out each sensor in sequence.
Defining a threshold distance is necessary for the controller to be able to distinguish between accidental obstacles and non-accidental obstacles. A non-accidental obstacle is an obstacle which presence at a given position is expected. A typical example of a non-accidental obstacle is the floor which forms the distal transverse edge of a vertical door. Another example is any piece of furniture or piece of architecture which stands in the proximity of the door, but represents no threat to the functioning of the shutter. A non-accidental obstacle will be detected by the sensors, but must be treated by the controller as a non-accidental obstacle. One way of excluding non-accidental obstacles from consideration is to vary the value of the threshold distance, dt(x1), as a function of the value, x1, of the distance of the leading edge to the distal transverse edge. For example, the distance of the floor to the leading edge of a shutter of a vertical door will always be equal to the instant value of x1(t) at any time. One way to exclude the return signal emitted by the floor during the closing of the shutter is to set the value of the threshold distance, dt(x1), as smaller than the value of x1 at any time (dt(x1)<x1(t)). The same applies to any other non-accidental obstacle which may return a signal during the closing of the shutter. In
In embodiments, the threshold distance dt(x1) can be a table expressing the threshold distance dt(x1) for a number of values of x1 or dt(x1) can be expressed as a mathematical function. The table or mathematical function can be stored in the memory of the controller In
As discussed above, the value of the threshold distance, dt(x1) of the sensors, can vary with the value of the instantaneous distance, x1(t). In some embodiments, dt(x1)<x1(t)+Δx1, wherein Δx1 is the distance between the sensor and the leading edge measured along X1.
In alternative embodiments, the instantaneous distances, di(t) of one sensor is compared with the instantaneous distances, di(t) of another sensor. In this case, the value of a threshold distance dt(x1) has to be construed as a value of di(t) measured with another sensor located on the leading edge. As long as two sensors measure the same instantaneous distance di(t), resulting from for example a reflection of the ultrasonic beam by the floor, no accidental obstacle is detected. If however a sensor measures an instantaneous distance di(t) that is lower than an instantaneous distance measured with another sensor, this indicates that an accidental obstacle is detected.
In some embodiments, as illustrated in
As known in the art, the ultrasonic beam emitted by the ultrasonic emitter/receiver unit 8.i has a specific three dimensional radiation or beam pattern. The beam pattern depends on the characteristics of the emitter such as the size and shape of the vibrating surface generating the ultrasonic waves and the frequency of vibration. The sound pressure level is the highest along the central sensor axis 6.i. The sound pressure level along an axis decreases with increasing values of an angle β formed by said axis with the central sensor axis 6.i. An example of a 2D polar plot resulting from a single plane cut through the 3D beam pattern is shown in
As the ultrasonic beam does not necessarily progress along a circular shaped cone but can for example form an elliptical cone, two sound pressure half angles β1 and β2 are generally defined by measuring the sound pressure half-angle β in two orthogonal planes and determining for each plane the sound pressure half-angle with respect to the central sensor axis where the sound pressure is reduced by a factor of 2. Manufacturers of ultrasonic sensors generally provide the values of the characteristic sound pressure half angles β1 and β2. Sometimes, instead of the half-angle β a full angle (=2×β) is specified by the manufacturer. In the present description, a half angle, β, is used.
In
Typically, the first sound pressure half-angle β1 as measured in the above defined plane (X1i, 6.i) is comprised between 15 and 45°. In preferred embodiments, the sound pressure half-angle, β1, is comprised between 20 and 35°.
In embodiments according to the invention, the sound pressure half-angle, β1, is greater than or equal to γ1 (i.e., β1≥γ1) as shown for example on
The second sound pressure half-angle, β2, measured long plane (X2′(x1), 6.i) is preferably comprised within 25° and 65°. The minimum required value of the second sound pressure half-angle, β2, depends on the number, n, of sensors used for a given door width and the spacing between two sensors. A larger distance between two sensors requires a larger value of angle β2, for preventing any blind spots between the acoustic expansion cones of two adjacent sensors, 8.i and 8.i+1. Generally, the β2 angle value is fixed by the sensor manufacturer and the number of sensors n is then determined by calculation taking into account the width of the door.
The ultrasonic sensors are further characterized by a maximum detection range MR, which is preferably at least 2 m, more preferably at least 3 m. If an obstacle is located at a distance from the sensor that is larger than the specified maximum detection range, it will not be detected. Typically the maximum range of sensors suitable for the present invention is comprised between 2 m and 5 m.
Examples of sensors comprising ultrasonic emitter/receiver units that can be used for the current invention are ultrasonic sensors used in the car industry as parking sensors. For example ultrasonic sensors provided by the company Bosch operate at a frequency of about 48 kHz and have a typical detection range from 20 cm up to 4.5 m. Such sensors have a sound pressure half-angle in a first direction of ±30° (also named vertical opening angle) and sound pressure half angle in a second direction of ±60° (also named horizontal opening angle).
The maximum detection distance, L1, from the area 20, ahead of the reference surface (defined as the main surface of the shutter holding a sensor), and measured along a direction parallel to the axis, X3, for detecting an accidental obstacle depends on the opening angle, γ1, and the sound pressure half-angle, β1. In
In embodiments according to the invention, 20°<β1+γ1<90° and −30°<β1−γ1<50°. In preferred embodiments, 25°<β1+γ1<60° and −10°<β1−γ1<40°. More preferably, 0°<β1−γ1<10°.
In the embodiment of
In some embodiments according to the invention, the motorized door further comprises a second series of sensors (3.j, with j=1 to m), wherein m≥2, similar to the sensors of the first series as defined above and which are distributed on the second main surface of the shutter, along and on or adjacent to the leading edge. In
A
Another example where both a first series and a second series of sensors are mounted on either sides of the leading edge 1L is shown in
In
The examples shown in
In embodiments according to the invention, the central axis 6.i of each sensor is generally, as shown in
In some embodiments, the motorized door comprises a detector for determining the instantaneous distance, x1(t), of the leading edge (1L) to the distal transverse edge 20D. This detector is configured for communicating this distance to the controller. In this way, based on the received information of x1(t) the corresponding threshold distance dt(x1) can be selected.
In some embodiments, a warning threshold distance dw(x1) is defined with dw(x1)>dt(x1), as illustrated in
By comparing successive measurements of the distance separating a detected obstacle and the moving leading edge of the shutter, the controller can determine whether such detected obstacle moves towards or away from the moving leading edge. Again the Doppler effect can be used to determine the velocity and direction of displacement of a moving obstacle. The stopping of the shutter may not be triggered in case the detected obstacle does not move towards the leading edge, although it has been detected within the threshold distance, dt(x1), of the sensors.
Unlike the motorized doors of the prior art, a motorized door according to the present invention comprises a detection system which allows:
| Number | Date | Country | Kind |
|---|---|---|---|
| 1630167-3 | Jun 2016 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/065614 | 6/26/2017 | WO | 00 |
