AU2007101214A4

AU2007101214A4 - Door operator with door position sensor

Info

Publication number: AU2007101214A4
Application number: AU2007101214A
Authority: AU
Inventors: Glen Edward Flemming; Jack Leivenzon
Original assignee: Smart Openers Pty Ltd
Current assignee: Automatic Technology Australia Pty Ltd
Priority date: 2007-12-20
Filing date: 2007-12-20
Publication date: 2008-02-07
Anticipated expiration: 2015-12-20
Also published as: AU2007101214B4; AU2007101214C4

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION Innovation Patent Applicant(s): Smart Openers Pty Ltd Invention Title: DOOR OPERATOR WITH DOOR POSITION SENSOR The following statement is a full description of this invention, including the best method for performing it known to me/us: 2 DOOR OPERATOR WITH DOOR POSITION SENSOR

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d) Field of the invention C 5 The present invention relates to sensing the position of a door. An example of an application of the invention is a door operator for tracking the position of a garage door Cl curtain such as in a roll-up garage door, tilt door or sectional door. The invention also has application in determining the position of a door in a sliding or swing gate such as in driveway gates.

Background Domestic and industrial garage doors are known to be provided with motor driven door operator mechanisms to automatically open and close the door. A position sensor is required to determine the position of the door to avoid driving the door beyond fully open and fully closed limits. The position sensor is used to feed back a position of the door to a controller of the door opener.

Known door openers use micro-switch position limit switches or shaft encoder counters or optical sensors to determine the door position.

A problem with known door operators is if there is an electric power supply failure, and the door is required to be manually opened or closed then there must be a physical disconnection of drive train between a drive motor and the door, as the mechanical advantage of the drive train is too great for a person to overcome by manually holding the door and manually attempting opening or closing. Thus when electric power is restored it is necessary to make a drive train reconnection if the door opener is to again perform opening and closing. Unless there is direct reengagement of the drive train in the exact same position as when the disconnection occurred, there will be N\Mclbourc\Cacs\Paienl\76000-76999\P763 I AU\Spcis\Spccificalion 2007-12-10 doc. Innovtiondoc 20/12107 3 O incorrect sensing of the fully open and fully closed U positions of the door. Complicated systems have been Sdevised in the past to ensure correct position reengagement and/or suitable adjusting of datums, so that the door will stop at the intended fully open or fully closed positions.

C1 There is a need for an alternative arrangement.

Summary of the invention According to one aspect of the present invention there is provided a door operator with door position sensor having a motor for providing drive power, a drive train adapted to couple dive power from the motor to a door to cause opening and closing of the door and a controller adapted to control the motor, the sensor co-operating with the controller to stop the door at a set open position and a set closed position, the sensor comprising: an active element connected in the drive train for relative rotation with a detector, said sensor being adapted to determine the rotational position of the active element relative to the detector consequent on opening or closing of the door; and wherein coupling from the drive train to the active element is adapted to cause less than 3600 relative rotation of the active element and detector over a range of full travel of the door and wherein the resolution of the sensor is able to accurately sense the door at the set open position and the set closed position whereby, if the drive train is disconnected and the door manually moved between open and closed positions, the active element will relatively rotate within the sensor with the door movement within a 3600 range and when the drive train is reconnected, the controller will be able to determine the position of the door relative to the set open and the set closed positions, such that the set open position and set N\Mclboumc\Cwses\Paacnt\7600.76999\P7631 I.AU\Spccis\Spccircation 2007-I2-I0,doc Innovotiondoc 20/I2/07 4 closed positions can be re-established from the resolution c-I Sof the sensor, and the door stopped at those set positions Swhen driven by said motor.

C)

C s5 According to another aspect of the present invention there is provided a sensor for a door operator having a motor _for providing drive power, a drive train adapted to couple CI dive power from the motor to a door to cause opening and closing of the door and a controller adapted to control Io the motor, the sensor co-operating with the controller to stop the door at a set open position and a set closed C position, the sensor comprising: An active element connected in the drive train for relative rotation with a detector, said sensor being adapted to determine the rotational position of the active element relative to the detector consequent on opening or closing of the door; and wherein coupling from the drive train to the active element is adapted to cause less than 3600 relative rotation of the active element and detector over a range of full travel of the door and wherein the resolution of the sensor is able to accurately sense the door at the set open position and the set closed position whereby, if the drive train is disconnected and the door manually moved between open and closed positions, the active element will relatively rotate within the sensor with the door movement within a 3600 range and when the drive train is reconnected, the controller will be able to determine the position of the door relative to the set open and the set closed positions, such that the set open position and set closed positions can be re-established from the resolution of the sensor, and the door stopped at those set positions when driven by said motor.

Preferably the active element is positioned with a gear coupled to the door operator drive train, and wherein the detector held in a fixed position adjacent the active N:\Mclbournc\Csc\Pacnt\76000-7698\P763 II ALJ\Specis\Specificatio 2007-12-IOdoc. Innovation doc 20/2107 5 element.

SIn a preferred embodiment the active element is a polarised magnet.

An embodiment of the detector comprises: a hall array sensor adapted to detect the angular Cl orientation of the polarised magnet as an analogue signal; a digital signal processor adapted to receive an analogue detection signal received from the sensor and to Sprocess the analogue signal to output a digital signal indicating the angular position and direction of rotation of the polarized magnet; a memory adapted to store an initial position, a current position and a direction of rotation; and an interface to enable data to be transferred between the door sensor and the door operator controller.

In an embodiment the sensor has a resolution of at least 4096 increments in 3600.

The detector as described above can be adapted to record a current relative polarized magnet position in memory as an initial position in response to an externally applied control signal. For example, in response to reestablishment of power to the door operator after power failure, the controller can be adapted to read a current position from the sensor to determine the position of the door relative to the set open and set closed positions.

Brief description of the drawings An embodiment, incorporating all aspects of the invention, will now be described by way of example only with reference to the accompanying drawings in which Figure 1 is a block diagram of a door operator N\Mclboume\Cscs\Parent\76000-76999\P763 II .AU"Spccis\Sp&iication 2007-12 I O.doc. Innovation.doc 20/12/07 6 SFigure 2 illustrates an exploded view of an embodiment of Sa door position sensor for a door operator Figure 3 illustrates an assembled view of the door position sensor of Figure 2 C Detailed description 1io Embodiments of the present invention relate to a door operator with door position sensor. The door operator has a motor for providing drive power, a drive train adapted to couple dive power from the motor to a door to cause opening and closing of the door and a controller adapted to control the motor. The sensor co-operates with the controller to stop the door at a set open position and a set closed position. The sensor comprises an active element connected in the drive train for relative rotation with a detector. The sensor is adapted to determine the rotational position of the active element relative to the detector consequent on opening or closing of the door.

Coupling from the drive train to the active element is adapted to cause less than 3600 relative rotation of the active element and detector over a range of full travel of the door and the resolution of the sensor is able to accurately sense the door at the set open position and the set closed position.

If the door is required to be manually opened or closed, for example in the event of a power failure, then there must be a physical disconnection of drive train between a drive motor and the door, as the mechanical advantage of the drive train is too great for a person to overcome by manually holding the door and manually attempting opening or closing. Thus when electric power is restored it is necessary to make a drive train reconnection if the door opener is to again perform N \Mlboume\Ca es\Patcn\t76000.768'9\P763 II AU\Spcc\Spccification 2007-12-I 0doc. Innoation doc 20/ 2107 7 -D opening and closing.

SIf the drive train is disconnected and the door manually moved between open and closed positions, the active element will relatively rotate within the sensor with the door movement within a 3600 range and when the Sdrive train is re-connected, the controller will be able C1 to determine the position of the door relative to the set Sopen and the set closed positions. This enables the set 10 open position and set closed positions to be reestablished from the resolution of the sensor, and the c door stopped at those set positions when driven by the motor.

An example of a door operator as described above is illustrated in block diagram from in Figure 1. The door operator 100 has a position sensor 110, a mechanical drive assembly 120, and a controller 130. An optional user interface 140, such as a remote control can also be provided. The mechanical drive assembly 120 includes motor 122 for providing drive power, and a drive train 125 adapted to couple dive power from the motor to a door (not shown in the block diagram) to cause opening and closing of the door. The controller 130 is adapted to control the motor and includes a motor controller 132 for executing motor control functions such as controlling the drive speed, direction and distance, an input output interface 134 to enable a user to input door open and close commands either manually or via a remote interface 140, and a position determination module 136 adapted to interpret position information accurately from the sensor 110 to stop the door at a set open position and a set closed position.

The sensor 110 comprises an active element 115, in this embodiment a polarised magnet, connected in the drive train 125 for relative rotation with a detector 118. The NALeIboumc\Cascs\Pateni\760-76999\P7631 I AUSpccisSpccifcafion 2007.1210.doc. Innoauion.doc 20/12107 8 O sensor 118 is adapted to determine the rotational position U of the polarised magnet 115 relative to the detector 118 Sconsequent on opening or closing of the door.

The detector 118 comprises a hall array sensor 150, a digital signal processor 160, a memory 170 and an interface 180 to enable data to be transferred between the CI door sensor 110 and the door operator controller 130. The detector 118 can be implemented in a single integrated circuit or using discrete components.

The hall array sensor 150 is adapted to detect the angular orientation of the polarised magnet 115 as an analogue signal. The hall array comprises a plurality of is individual sensors which are used to sense the distribution of the magnetic field generated by the polarised magnet 115 over the surface of the array and deliver an analogue voltage representation of the magnetic field over the array to the digital signal processor for analysis. The digital signal processor 160 is adapted to receive an analogue detection signal received from the hall array sensor 150 and to process the analogue signal.

The analogue signal is converted to a digital signal and analysed to determine the angular position and direction of rotation of the polarized magnet 115. This information is output as a digital signal for storage in memory or use by the door operator controller 130.

It should be appreciated that the polarised magnet may be substituted for another form of active element adapted to generator a polarised magnetic field for detection by the hall array. Alternative active element and detectors combinations adapted to determine with sufficient accuracy the relative angular rotation of the active element and detector are envisaged within the scope of the invention.

The memory 170 is adapted to store an initial position N \Mclboume\Case\Patent\76000-76999\P763 I I AU\Spccis\Spccificaion 2007-12- O.doc. Innovitondoc 20/ 2/07 9 O 172, a current position 174 and a direction of rotation 176 of the magnet 115. The initial position can be stored Sduring a door installation process to set a "zero" or reference position for the sensor magnet 115 relative to the hall array 150. The current relative polarized magnet position may be recorded in memory 170 as an initial _position 172 in response to an externally applied control Cl signal, for example applied via the controller 130 in response to installation control instructions input by an installer. Typically an installer will cause this initial reference position to be stored with the door in a fully open or fully closed position such that the reference position coincides with a set open position or a set closed position of the door. However this is not is essential as the set open and set closed positions used by the controller 130 may be stored as relative positions to this reference position. An advantage of being able to store the initial or reference position is that the magnet does not have to have its polarity aligned with a predetermined direction, as this can be awkward or impossible to do during installation particularly if the magnet is provided prefabricated in an element of the drive train 125.

Coupling from the drive train 125 to the magnet 115 is adapted to cause less than 3600 relative rotation of the magnet 115 and detector 118 over a range of full travel of the door and the resolution of the sensor is able to accurately sense the door at the set open position and the set closed position. By ensuring that the magnet will rotate less than 3600 over the range of travel of the door, the angular position of the magnet 115 relative to the detector 118 can be translated directly to a door position relative to the set fully open and fully closed positions.

Ensuring that less than 3600 rotation will occur can be achieved using appropriate gear ratios between the drive train elements associated with the door and the drive N\Mclboume\Cascs\Paen 76lO-76S99\P763[ I .ALSpcisSppccirication 2007-12-0doc Innovaiondoc 20/I2107 10 train element carrying the magnet or active element.

SIf the drive train is disconnected and the door manually moved between open and closed positions, the magnet 115 C s will rotate with the door movement within a 3600 range due to the coupling of the magnet to the drive train. When the drive train is re-connected to the motor, the CI controller will be able to determine the position of the door relative to the set open and the set closed positions from the sensed relative positions of the magnet 115 and Sdetector 118. This enables the set open position and set c closed positions to be re-established from the resolution of the sensor, and the door stopped at those set positions when driven by the motor.

An advantage of using a magnetic sensor is that no battery backup is required to ensure the door position is recorded in memory or tracked during a power failure to the door operator. In response to re-establishment of power to the door operator after power failure, the controller is adapted to read a current position from the sensor to determine the position of the door relative to the set open and set closed positions.

A further advantage of using an active element and a detector, such as a magnet and a hall array sensor, is that the sensor is not prone to interference due to dust, insects or humidity. Further, as this type of sensor is contactless the sensor is not prone to degradation due to mechanical wear and tear. Thus the sensor is robust and suitable for use in a typical garage environment prone to dust and insects.

The sensor requires an adequate resolution to equate the angular rotation of the magnet to the distance of travel required for the door. The required resolution may vary based on the distance of travel for the particular door N \Mclboume\Cases\Patent\76000-76999\P763 II AU\Specis\Spccilication 2007.12- I0doc Innovaliondoc 20/12107 11 O application. For example a sensor having a resolution S1024 positions per revolution can determine the magnet's Sangular position with a resolution of about 0.350 and this resolution may be sufficient for application in an embodiment such as a swing or sliding gate having a required travel distance of travel of 1.5m. This Stranslates to an accuracy of 1.4mm increments. In an C alternative embodiment suitable for a 5m high roll-up door Sthe sensor may require a resolution of around 4096 10 increments in 3600. This translates to an accuracy of 1.2mm increments. In practice such accuracy is sufficient for swing or sliding gates, and roll up, lift or sectional doors.

An example of a suitable detector is illustrated in Figure 4. The detector 400 hall array comprises four linear hall sensors 410 which generate a DC output voltage proportional to the strength of the magnetic field incident on the sensor. The four linear hall sensors 410 are arranged symmetrically under the hub 420 of rotation of the polarised magnet 430, such that rotation of the magnet generates four sinusoidal waveforms each having a 900 phase offset from its neighbouring sensors. As shown in Equation 1: HI= asin(a) H2 a sin(a 900) a cos(a) [1] H3 a sin(a 1800) a(-sin(a)) H4 a sin(a 2700) a(-cos(a)) where: a peak amplitude 3o c magnet rotational angle relative to sensor Using differential amplifiers 440 and 450 to amplify the output of opposite sensors, adds the signals to generate two 90° phase shifted signals 460 and 470 having double the N\Mciboumc\Cases\Patent\7600-76999\P763 IAU\Specis\Speciicaion 2007- 2-1Odoc Innovationdoc 20/12/07 12 amplitude, as shown if Equation 2.

SHI -H3 asin(a)- sin(a)) 2asin(a) H2- H4= a cos(a) cos(a)) 2acos(a) These two analogue signals can be converted to digital Ssignals for further processing using an analogue to CI digital converter (ADC) 490, for input to the digital signal processor (DSP) 495 for further processing. The DSP 495 can transform the signals into angle information using the relationship shown in Equation 3.

('2a sin(a) sin(a) A arctan 2acos( =arctans(a) [3 2acos(a) cos(a)) where: A measured angle a peak amplitude c magnet rotational angle relative to sensor The accuracy of the angle determination and hence the door position determination is influenced by the resolution of the ADC 490 and the capability of the DSP 495. For example using 12 bits enables a resolution of 212=4096 steps/revolution or 0.087890 per step.

An embodiment of a sensor assembly for a door operator is illustrated in an exploded form in Figure 2 and in an assembled form in Figure 3. This embodiment of the sensor assembly 200 comprises a two part housing having a base housing portion 240 for mounting the sensor to a door operator assembly and a top housing portion 250. The polarised magnet 225 is mounted in the hub of a first gear 228 which is adapted to couple to a second gear 225 in the assembled sensor 200. The second gear 225 is adapted to be coupled to the drive train when the sensor is mounted in a door operator assembly. The detector 218 is provided as signal integrated circuit chip which is mounted on a N\Melboume\Cses\Paten\76-OO7699 P763 I ALPSpcis\Specification 2007-I2- 0 doc Innovationdoc 20/12107 13- 0 circuit board which, in turn, is supported on arm 230 U which is mounted to the housing base 240, such that the Sdetector chip 218 will be aligned with the magnet 215 in the hub of the first gear 228 in the assembled sensor 200.

The circuit board can be connected in data communication with the door operator controller for transfer of data from the sensor to the door controller.

It should be appreciated from the assembly illustrated in Figures 2 and 3 that coupling of the second gear 225 to the drive train of the door operator causes the second gear to rotate when the door is opened or closed which, in turn, causes, rotation of the first gear 228 and the magnet 215 therein. The rotation of the magnet 215 is detected by the detector chip 218 and via the circuit board on the arm 230 the position information transmitted to the controller. The illustrated sensor assembly represents one possible embodiment of a sensor for a door operator. It should be appreciated that alternative embodiments are envisaged within the scope of the invention defined in the following claims.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in any other country.

N \Mlboumc\Cas\Paie\76>ODO-76999\P763i I AU\Spccis\Specification 2007-12-10 doc. Innoviiondoc 20112107