Patent Publication Number: US-2015059249-A1

Title: Electrical door operator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. application Ser. No. 12/416,622, filed on Apr. 1, 2009 which claims the benefit of U.S. Provisional Application Nos. 61/041,696, filed on Apr. 2, 2008 and 61/054,952, filed on May 21, 2008. The entire disclosures of each of the above applications are incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure is related to door operators and, more specifically, to electrically-operated door operators. 
     BACKGROUND 
     The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     Installing doors into buildings under construction typically requires the assistance of various tradesmen. For example, for one opening, tradesmen such as carpenters, painters, glaziers, electricians, and drywallers are required to complete the installation of the door. Other tradesmen may also be used for the installation of the door. The number of tradesmen increases when the door has security or other specialty items incorporated near the door opening. Reducing the number of tradesmen will reduce the overall cost of the door when installation is included. Also, a reduction in human factors may also be reduced. 
     Door operators are typically designed around the concept of a return spring capable of exerting latching pressure with a spring alone. For example, many return springs provide about 15 lbs. of latching pressure using a spring. A motor large enough to overcome the spring pressure must be provided to operate a door operator. A door operator is capable of moving a door from an open position to a closed position, as well as from a closed position to an open position. Because of the size of the spring and the motor, a box that is approximately 6″×6″×36″ is mounted, in plain view, over the door opening to house the motor and spring. Providing such door hardware in plain view may reduce the aesthetic appeal of the opening. 
     SUMMARY 
     The present disclosure provides a door operator assembly that does not include a return spring. Further, the electrical door operator is concealed within the door to provide a more aesthetically-pleasing door assembly. A conventional operator or closer develops increasingly high closing pressures as the door is opened putting handicapped or elderly people in danger of injury. This pressure approximates 20 pounds. The operator pressure according to the present disclosure can be maintained to a significantly lower pressure during the full operational distance. Forces in the 1 to 2 pounds range are possible. 
     In one aspect of the invention, a springless door operator for a door includes an arm extending from the door operator. The door operator includes a motor moving the arm to move the door between a closed position and an open position and between the open position and the closed position. A current sensor generates a current signal corresponding to the current to the motor. A position sensor in communication with the door arm generates a position signal corresponding to the position of the door relative to the frame. A controller communicates with the sensor and the motor. The controller controls a motor current to the motor in response to the current signal and the position signal. 
     Further areas of applicability of the present disclosure will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a front elevational view of a door having a door operator assembly according to the present disclosure; 
         FIG. 2  is a top view of the door and door operator assembly of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of a door operator assembly for use in a retrofit situation; 
         FIG. 4  is cross-sectional view of a door with an originally-fitted closer; 
         FIG. 5  is a block diagrammatic view of a door system according to the present disclosure; 
         FIG. 6A  is a simplified block diagrammatic view of the motor and actuator of a door operator assembly; 
         FIG. 6B  is an alternative simplified block diagrammatic view of the door operator assembly; 
         FIG. 6C  is another alternative simplified block diagrammatic view of the door operator assembly according to the present disclosure; 
         FIG. 6D  is yet another alternative simplified block diagrammatic view of the door operator assembly operated under the control of a motor and hydraulics; 
         FIG. 7  is a simplified block diagrammatic view of a circuit board for use in the door operator assembly; 
         FIG. 8  is a flowchart showing a method of operating the door operator assembly of the present disclosure; 
         FIG. 9  is a flowchart showing a method for controlling the operating current of the door in the present disclosure; 
         FIG. 10  is a flowchart showing a method for setting and changing the operating current of the door; 
         FIG. 11  is a flowchart of a method for operating the door during a power failure; and 
         FIG. 12  is a flowchart of a method for operating the door using a predetermined limit speed and predetermined force limit. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is in no way intended to limit the disclosure, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical or. It should be understood that steps within a method may be executed in different order without altering the principles of the present disclosure. 
     As used herein, the term module refers to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. 
     Referring now to  FIG. 1 , the present disclosure us set forth with respect to a door  10 . The door  10  has a frame  12  that comprises horizontal stiles  14  and vertical stiles  16 . The horizontal stiles  14  and vertical stiles  16  may be formed of a variety of materials, including wood, metal or a composite material. 
     The door  10  has a pair of outer faces  18 , only one of which is illustrated in  FIG. 1 . The outer faces  18  may be referred to as “door skins.” The outer faces  18  may comprise various materials, including metal, wood and composite materials. The interior of the door  10  between pieces of the door frame  12  and the door skins  18  may be filled with various materials, including, but not limited to, spacers and fire resistant materials, depending on the type of door. 
     The door  10  may also include a door operator assembly  20 . Although the door operator assembly  20  is described below as being disposed within the door  10  between the door skins  18 , the door operator assembly  20  may be disposed partially within the door or on the face of the door. The door operator assembly  20  may be springless to reduce the size of the operator assembly  20 . By forming the door operator assembly without a return spring, the forces that the door operator controls are more easily and safely controlled. Not having to overcome the return spring force allows a reduced size for the components within the door operator assembly  20  including the motor. 
     The door operator assembly  20  includes an arm  22  extending from the door operator assembly  20  that may be used to position the door  10  and move the door into the desired position. The arm  22  may extend from the door operator to the door frame or to a track on the wall adjacent to the door frame. The arm  22  may also be a compound arm common to closers and automatic operators. A latch operator  24  may also be disposed within the door skin  18 . The latch operator  24  is associated with a door handle  26  that latches and unlatches the door. The latch operator  24  may be an electrically-operated latch operator, such as a motor or solenoid. The latch operator  24  may be in communication with the door operator assembly  20  and may operate under the control of the door operator assembly  20 . The latch operator may also initiate the opening cycles. (Details of the operation of the door operator assembly  20  and the latch operator  24  will be provided below.) The latch operator  24  may be a mechanical operator that is electrically locked or operated in response to sensing the movement of the door handle  26 . One example of a mechanical latch operator is a panic bar. The latch operator  24  may be in communication with a latch mechanism  30  that is used for latching the door  10  within an external frame, as described below. A hinge  32  is used for rotating the door  10  within the external frame. Both the latch mechanism  30  and the hinge  32  may extend vertically along the entire edge of the door  10 . 
     A proximity sensor  36 , such as an antenna, may also be incorporated within the door  10 . By providing the proximity sensor  36  within the door  10 , the aesthetic appeal of the door is maintained. The proximity sensor  36  may sense the approach of an object or person and the speed of an object or person, and allow the door operator assembly  20  to operate accordingly. The proximity sensor  36  is in communication with the door operator assembly  20 . 
     Referring now to  FIG. 2 , the door  10  is illustrated within an external door frame  50 . The door frame  50  fastens the door  10  to a wall  52 . The hinge  32  allows the door  10  to pivot about an axis within the frame  50 . The door frame  50  may include or have an additional track  54  that allows a first end  55  of the operator arm  22  to slide therein in the direction indicated by arrows  58 . As the position of the arm  22  rotates (as indicated by arrow  61 ) at a second end  59  to change the position of the door  10 . The arm  22  is ultimately operated by motor and gear components within the door operator assembly  20 , as will be further described below. Latch mechanism  30  engages the door frame  50  or another door in a double-door application. 
     Referring now to  FIG. 3 , a side cut-away view of a door  10  is shown, illustrating a door operator assembly  20  having the arm  22  attached thereto. The arm  22  may be attached to a motor within door operator assembly  20 , as will be described below. The first end  55  of arm  22  slides within the track  54  associated with a door frame  50 . The track  54  may be referred to as a “concealed track” or “U-shaped” since only one end of the channel forming the track is open. That is, the track  54  may have a top side and a bottom side, and one of the sides opened to receive the arm  22 . A stop  60  is integrally-formed with the door frame  50 . The door  10  rests against the stop  60  in a closed position. The configuration of  FIG. 3  is suitable for retrofitted doors in which the track  54  is added to the stop  60  and the door  10  then assembled within the door frame  50  to receive the arm  22 . 
     Referring now to  FIG. 4 , a new construction type door assembly  62  is illustrated in which the track  54  is integrally formed with or attached to the top of the door frame  50  without a stop  60 , as illustrated in  FIG. 3 . As the door  10  opens and closes under the influence of the door operator assembly  20 , the first second end  55  of the arm  22  remains within the track  54 . 
     Referring now to  FIG. 5 , the door  10  and the door operator assembly  20  are illustrated in further detail. The door operator assembly  20  includes a controller  110 . The controller  110  may, for example, be a microprocessor-based controller. The controller  110  may be used to control various actions or outputs based upon various inputs. 
     The controller  110  may receive an input from a door operator arm position sensor  112 . The door operator arm position sensor  112  generates a signal corresponding to the angular position of the operator arm  22 . The angular position may be the position relative to the door  10 . As the door  10  opens, the angular position signal corresponds to a larger angle than when the door is in a closed position. In a closed position, the angular position may be about zero. Various types of sensors may act as the position sensor  112 , including a resistive sensor, a Hall Effect sensor, a pulse-counting sensor or an accelerometer that counts the amount of angular pulse signals from a door operator. Various types of sensors may be used. Based on the position sensor, the change in position over time, such as the opening speed and closing speed, may be obtained. The controller may supply only enough energy or current to overcome friction and inertia to maintain a programmed speed. The acceleration or change in speed over time may also be derived from the position sensor. The force of the door may also be derived based upon the acceleration derived from the position sensor  112  and the mass of the door which may be determined during manufacture or estimated based on the features of the door assembly. The closing force of the door may be charged to overcome stack pressure of the building and physical obstructions. The closing force may be maintained below a predetermined force. The speed may also be maintained below a predetermined speed. The controller  110  may be able to distinguish between an object or stack pressure based on various sensors and a current or speed profile. 
     The controller  110  may also be in communication with a current sensor  114 . The current sensor  114  generates a current signal corresponding with the amount of current being applied to a door operator  116 . The controller  110  may control a door operator  116 . The door operator  116  may be various types of door operators, as will be described below. The door operator  116  may, for example, be a motor, a motor with a hydraulic pump or a pump with a plurality of gears, such as a rack gear or the like. By monitoring the current within the current sensor  114 , the controller  110  can provide more or less opening force, change the velocity of the door opening or closing, or change the acceleration of the door opening or closing. 
     The motor of the door operator  116  may act as a generator to recover kinetic energy from the opening process. As will be described below, upon a power failure or sensing of a power interruption, the motor may only act to close the door from an open position to a closed position. When the door is pushed open, the motor may act as a generator to recharge a rechargeable power source such as a battery or capacitor. 
     The controller  110  may also receive environmental signals from an environmental sensor  118 . The environmental sensor  118  may be one sensor or a plurality of sensors that sense the environmental conditions around the door  10 . One example of an environmental sensor  118  is a smoke detector that generates a smoke signal in response to a smoke condition. The environmental sensor  118  may also be a temperature sensor that senses the temperature around the door  10 . The environmental sensor  118  may also be a toxic agent sensor that generates a toxic agent signal in the presence of toxic agents. Various types of toxic agents may be sensed, including, for example, radiation. Light levels may also be sensed by the environmental sensor  118 . That is, the environmental sensor  118  may be a light sensor that generates a light signal corresponding to the amount of ambient light within an area around the door  10 . 
     The environmental sensor  118  may sense one or more atmospheric conditions around the door such as wind, rain, snow, weather and other conditions. Based on these conditions, the controller  110  may generate an immediate speed for motor current change in response to the environmental condition or conditions. 
     The controller  110  may also be in communication with an access controller  120 . The access controller  120  may provide access for latching and unlatching the door through a latch operator  126 . The access controller  120  may be a PIN pad, a fingerprint recognition system, a voice recognition system, a retina recognition system, or various combinations of the above. The access controller  120  may also be a card reader or the like. The access controller  120  may also be in communication with a clock  122  that records the time of various entries and exits through the door  10 . In conjunction with the access controller  120 , specific persons may be tracked based upon entry using the access controller  120 . The access controller  120  may also monitor and track attendance of various assets and the movement of the access or attendance of various persons or access within a building. The access controller  120  and clock  122 , in combination, may also unlock and lock various doors of a building based upon the calendar within the clock and the time associated with the clock. 
     The controller  110  may also control a latch operator  126 . The latch operator  126  may be a mechanical-based or electrical-based latch operator. The latch operator  126  may be used to lock the door  10  based upon inputs from the clock  122  or other inputs such as those from a central controller  128 . The latch operator  126  may allow the latch to be unlatched without the intervention of a person. By unlatching the door  10 , the latch operator  126  may then be easily moved by the motor associated with the door operator  116  into the desired position. 
     The proximity sensor  36  may also be an input to the controller  110 . The proximity sensor  36  may be one of a variety of sensors, such as the antenna illustrated in  FIG. 1 . Other types of proximity sensors  36  may be included within the door  10  and outside the door. For example, the proximity sensor  36  may be a motion detector that can gauge the speed of an approaching person or object and open the door  10  corresponding to the speed of the approaching person or object. On example of a suitable use is to sense the speed of an approaching gurney in a hospital environment. The proximity sensor  36  may also be a wall switch that activates door operator  116 , or other type of sensing device, such as a floor-mounted pad sensor. The proximity sensor  36  may also generate a signal to the controller  110  that, in response the proximity sensor  36 , unlatches the latch through the latch operator  126 . Thus, a latch open signal may be generated by the controller  110  to unlatch the latch based upon a proximity signal corresponding to a person or object in proximity of the proximity sensor  36 . The latch operator  126  may also generate a latch completion signal to signal the controller  110  that opening the door  10  is enabled since the latch is open. 
     The controller  110  may also be communication with an indicator  130 . The indicator  130  may be an audible indicator, such as a buzzer, beeper or bell, or a visual indicator, such as a light-emitting diode, a display or a light. Audible signals, visual signals or both may be used in a particular system. The indicator  130  may generate an indicator in response to an alarm. By knowing that a particular door should not be opening and when the arm position sensor  112  generates a signal corresponding to the opening of the door during a guarded time period, the indicator  130  may generate an indicator corresponding to an alarm. 
     The controller  110  may also be in communication with a communication interface  140 . The communication interface  140  may communicate with the central controller  128  or other door controllers of a building. The communication interface  140  generates signals in the proper format and potentially with encryption to the central controller  128 . The controller  110  may communicate alarm signals to the central controller  128  through the communication interface  140 . The central controller  128  may also generate control signals to the controller  110  to change various time periods associated with the door  10 , such as lock-down times, door-opening times, speeds and accelerations. 
     An external proximity sensor  142  may also be in communication with the controller  110 . The external proximity sensor  142  may be a wall-mounted switch or motion-detecting device that communicates a proximity sensor signal to the controller  110 . 
     A power source  150  may be in communication with the door operator assembly  20 . The power source  150  may, for example, be in communication with the door operator  116  and the controller  110 . The power source  150  may be internal or external to the door assembly. A power failure sensor  151  may be coupled to the power source  150  that generates a signal that is indicative of a power failure or power interruption. The sensor  151  may be located in various locations of the door operator assembly  20 . A door assembly may have backup power because sensing a power failure on incoming power is important so that the controller  110  may change modes and operate differently if required. 
     Other devices within the door  10  may also be in communication with the power source  150  such as the latch operator  24  and various sensors. The power source  150  may be a rechargeable power source such as a battery or capacitor that is used to operate the door operator assembly  20 . The power source  150  may be located between the door skins  18  illustrated in  FIG. 2  within the door  10 . The power source  150  may be a rechargeable power source that is recharged by a solar cell  152 . The power source  150  may also be easily removable so it can be readily replaced. 
       FIGS. 6A-6D  provide alternative embodiments to the layout within the door cavity. 
     Referring now to  FIG. 6A , the door operator assembly  20  is illustrated with a high-level block diagrammatic view. In this embodiment, the door operator  116  may comprise a motor  210  and an actuator  212 . The motor  210  may have a vertical axis  214  oriented in a vertical direction. The actuator  212  may comprise gears and the like. The actuator  212  may comprise various types of gears, including planetary gears, worm gears, spur gears, and the like. The actuator  212  has a shaft  216  that is rotatably coupled to the arm  22  of  FIGS. 1 and 2 . Each of the embodiments below have the shaft  216  rotatably coupled to the arm  22 . 
     A circuit board  220  may be incorporated within the door operator assembly  20 . The circuit board  220  may house the controller and various other components, as described below. Sensors may also be disposed on the circuit board  220 . The circuit board  220  may comprise one circuit board or multiple circuit boards that are arranged to fit between the outer skins illustrated in  FIG. 2  of the door. Each of the embodiments below may include the circuit board  220 . 
     Referring now to  FIG. 6B , the actuator  212  of  FIG. 6A  may include planetary gears  226  and a secondary gear set  228 . The secondary gear set  228  may comprise spur gears or the like. The motor  210  may be coupled to the planetary gears  226  using a belt drive  230 . A belt  231  extends from a first gear  232  coupled to the motor  210  and a second gear  234  coupled to the planetary gears  226 . 
     Referring now to  FIG. 6C , the motor  210  is oriented axially with a gear set  240 . The gear set  240  is in communication with the operator arm  22  (not illustrated). 
     Referring now to  FIG. 6D , the motor  210  is used to drive a pump  260 . The pump  260  is in fluid communication with a hydraulic drive  262 . By increasing the speed of the motor  210 , various pressures of hydraulic fluid may be provided to the hydraulic drive  262 . A gear  264 , which may be different or similar to the gear sets  240 ,  228  described above, may couple the hydraulic drive  262  to the arm  22 . 
     In each of the embodiments illustrated in  FIGS. 6A-6D , the motor  210  and actuator are sized to be fully received between the door skins of the door  10 . The gears are sized and positioned to convert the rotary motion of the motor  210  into motion of the arm  22 , which in turn opens or closes the door  10 . 
     Referring now to  FIG. 7 , the circuit board  220  of  FIGS. 6A-6D  is illustrated. Various components may be mounted on or coupled to the circuit board  220 . Various sensors are illustrated with reference numeral  280 . The various sensors  280  may be the sensors illustrated in  FIG. 5 . At least some of the sensors  280  may be mounted directly on this circuit board  220 . 
     The controller  110  may include an opening module  282 . The opening module  282 , based upon the various sensors  280 , may control the opening position, opening speed and opening acceleration of the door relative to the door frame. The opening module  282  may be disabled during a power failure. A power failure may cause the motor to act as a generator during operating of the door so that a power source may maintain a charge. The charge may be capable of being maintained indefinitely. 
     A closing module  284  may also be provided within the controller  110 . The closing module  284  may control the closing position, closing speed and closing acceleration of the door  10  of the controller  110 . Both the opening module  282  and the closing module  284  may have several regions defined for different speeds, accelerations and positions. For example, the opening module  282  may provide an unlatching force in a first range, which corresponds to providing a predetermined current to obtain a predetermined velocity of the door at a predetermined acceleration. Once the door is unlatched and opened greater than a first predetermined amount, the first door speed or acceleration may be adjusted by controlling the motor current to a second door speed or acceleration. When close to being open after a second predetermined door position, the door speed or acceleration may change. Of course, multiple regions corresponding to the position may be provided so that different speeds of the door may be provided. The closing module  284  may, likewise, have different speeds and velocities associated with various positions. Several regions may also be provided for the closing module  284 . When the door is nearly closed, the velocity for latching may be maintained by increasing the current to the motor to overcome the stack pressure of the building. Also, both modules  282  and  284  may compensate for wind pressure in either direction. That is, a wind forcing the door open while the opening module  282  is opening the door may require a resistive current to resist the speed of the wind. Likewise, if the wind is against the opening direction, additional current may be required to maintain the desired velocity of the door. The clock  122  and communication interface  140  may also be incorporated onto circuit board  220 . The closing module may compensate for stack pressures as the door closes. The stack pressures may change and therefore the system also changes the current to the motor based on the speed of the door closing. That is, if more force is required due to stack pressure increases, more current is provided to the motor for closing. 
     Referring now to  FIG. 8 , one method of operating the door is set forth. In step  310 , the position of the door is sensed by the door operator arm position sensor  112  illustrated in  FIG. 5 . In step  312 , the speed of the door relative to the frame is sensed (or derived). As will be described below, the position and the speed of the door allows the controller to control the current to maintain desired speeds and positions. In step  314 , it is determined whether the door is closed. If the door is closed, step  316  determines whether an alarm mode has been activated. In an alarm mode, the door should not open. If an alarm mode has been activated in step  316 , step  318  determines the door speed. If the door speed is not greater than zero, then step  312  is again performed. In step  318 , if the door speed is greater than zero, then an alarm is activated in step  320 . 
     Referring back to step  316 , if the alarm mode has not been activated, it is determined whether the door is desired to be opened in step  324 . If the door is not desired to be opened, step  326  is performed. Step  326  maintains the door in a closed position. 
     In step  324 , if the door is desired to be opened, it is determined whether the door has been unlatched. If the door has not been unlatched, the door may be unlatched in step  330 . The unlatching of the door may be mechanically or electro-mechanically performed using the latch operator. If the door is unlatched, step  334  is performed. In step  334 , it is determined whether the position of the door is less than a first position. The position of the door is determined constantly throughout the process since the door is ever changing. When the door is less than the first position, the current is set to an unlatching current in step  336 . If the position is not less than first position, it is determined whether the position is between a first position and a second position in step  338 . If the current is between a first and a second position, step  340  sets the current to a second opening current. In step  338 , if the position of the door is not between a first position and a second position, step  344  may be performed. Step  344  determines whether the position is greater than a third position, but less than a fully-opened position. If the position is between the third position and the fully-opened position, step  346  sets the current to a third operating current. If the position is not between the third position and the fully-opened position, step  348  determines whether the door is in the opened position. If the door is not in the opened position, step  344  is again performed. If the door is in the opened position, step  350  holds the door in the open position. Step  352  ends the process. 
     Steps  336 ,  340  and  346  illustrate various operating currents that are used that correspond to various positions of the door. Different currents may be used to obtain different speeds or accelerations, as will be set forth in  FIG. 10 . Although the three different door positions and the opened positions are set forth, various numbers of positions corresponding to different currents may be provided, including less than three positions, such as one current for the entire door swing or more than three intermediate positions. 
     Referring back to step  314 , it is determined whether the door is desired to be closed in step  360 . If the door is not desired to be closed in  360 , step  362  holds the door open. It should be noted that the hold open current for the door in step  362  and step  350  above may be a relatively low current since a return spring is not provided in the present configuration. In step  364 , it is determined whether the position of the door is greater than a fourth position. If the position is greater than a fourth position, the closing current may be set to a first closing current in step  366 . In step  364 , if the position is not greater than a fourth position, step  368  is performed. In step  368 , it is determined whether the position is between a fourth position and a fifth position. If the position is between a fourth position and a fifth position, the current may be set to a second closing current in step  370 . If the position is not between a fourth position and a fifth position, step  372  may be performed. In step  372 , it is determined whether the position is greater than a fifth position. If the position is greater than a fifth position, step  376  is performed. If the position is not greater than a fifth position, step  378  may be performed. In step  378 , it is determined whether or not the door is to be latched. If the door is not to be latched, the method ends in step  352 . If the door is to be latched in step  378 , the door is latched in step  380  and the process ends in step  352 . The door may be mechanically or electro-mechanically latched in step  380 . 
     Referring now to  FIG. 9 , during the entire operating process of  FIG. 8 , the current may be sensed. This is illustrated in step  410 . In step  412 , a current pattern may be determined. The current pattern may look at the current for a time preceding the last current reading. The current readings may be performed at regular intervals. In step  414 , the position of the door may also be used to determine whether or not an obstruction is present. In step  416 , an obstruction is determined. An obstruction may be determined by looking at the current pattern, the position of the door or both. If there is no obstruction, step  410  is again performed. Examples of obstructions may include a person contacting the door, door latch or door hinge. For example, fingers in the door hinge or latch may be an obstruction. 
     In step  416 , if there is an obstruction, the movement of the door is stopped in step  418 . It should be noted that the detection of the obstruction may be performed when the door is both opening and closing. In step  420 , the current is slowly increased. If the position does change in step  422 , the current is continually increased. If the position does not change in step  422 , the current is reversed in step  424  to back up the door position to a previous position. 
     Referring now to  FIG. 10 , the setting of the current in steps  336 ,  340 ,  346 ,  366 ,  370 , and  376  of  FIG. 8  are illustrated in further detail. Each of the steps  336 ,  340  and  346  may have similar elements and are, thus, described here in further detail. In step  510 , the current is set as provided above in one of the steps, such as  336 ,  340  and  346 . In step  512 , the speed of the moving door is determined. In step  518 , the actual speed of the door or the acceleration is compared to a desired speed or desired acceleration. It should be noted that the acceleration of the door may be determined by determining a change in the speed sensed in step  512 . In step  518 , if the actual speed or acceleration is less than a desired speed or acceleration, the current may be increased in step  520 . This allows the actual speed or acceleration to be increased to the desired speed or acceleration. It should be noted that both the speed and the acceleration may be increased by increasing the current in step  520 . If the actual speed or acceleration is not less than the desired speed or acceleration, step  522  is performed. In step  522 , if the actual speed or acceleration is greater than the desired speed or acceleration, step  524  is performed. In step  524 , a braking current is provided to prevent the door from going faster than the desired speed or acceleration. This may occur when someone or some force is pushing on the door. The force may include a person pushing on the door or wind. If the actual speed or acceleration is not greater than the desired speed or acceleration, the system is operating as it should and the current is maintained in step  526 . 
     Referring now to  FIG. 11 , a method for operating a door during a power failure is set forth. In step  610 , the door is operating, e.g., opening and closing. In step  612 , it is determined whether a power failure has been sensed. A power failure sensor as described above may be provided to determine whether a power failure has occurred. A power failure may occur when the power to the door from an external source has been interrupted. If a power failure has not been determined, step  614  continues normal operation. 
     In step  612 , when a power failure has been sensed, step  616  disables the door opening module  616 . If the system does not include a door opening module, the use of the door operator assembly is disabled for the opening of the door. In step  618 , the door may be opened manually by a user of the door. During manual opening of the door, the motor acts as a generator and generates charging current upon the opening of the door. The charging current is provided to the rechargeable power source in step  622  to charge the rechargeable power source. In step  624 , the door closing module operates the door to a closed position after the door has been opened from the rechargeable power source. 
     Referring now to  FIG. 12 , a method for operating the door using a force limit is set forth. In step  650 , a closing limit force is established. The closing limit force may, for example, be in the range of about 1.5 lbs. to about 2.0 lbs. of force. Of course, various ranges of forces may be used depending upon the application. The closing limit force may change, as mentioned above, depending upon various angles of the door. When the door is nearly closed, an increased limit force may be set so that stack pressures may be overcome. 
     In step  652 , a closing limit speed may also be set. When monitoring the closing limit speed, the motor current can be increased to overcome stack pressures in the final closing motion. 
     In step  654 , the door position is monitored during operation. In step  656 , the door speed and acceleration may be derived from the door position and also monitored. In step  658 , the door current may be monitored. In step  660 , the door is closed using the door closer. 
     In step  662 , when the speed is greater than a predetermined limit speed, the speed may be reduced using the motor current  664 . The motor current may provide a braking current to reduce the speed to a predetermined value. 
     If the speed is not greater than the predetermined limit speed in step  662 , step  666  determines whether the force is greater than a predetermined force. If the force is greater than a predetermined force, step  668  reduces the force by reducing the motor current. In step  666 , if the force is not greater than the predetermined force, steps  654 - 666  are again performed. 
     The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification, and the following claims.