Patent Application
20160164575
The disclosure relates generally to enclosures for control systems. More particularly, the disclosure relates to enclosures with wireless communication features.
Enclosures for control systems protect control units inside the enclosures from the elements. The enclosures may be fully or partially sealed to keep out moisture and particulate matter that could damage the control units. As used herein control units refer to any device configured to control a load based on control parameters. Control units generally include application logic and interfaces to receive input data from sensors and to output electrical power to a load, such as a motor. Control units are often used in fluid supply systems, but as used herein control units are not so limited.
A fluid supply system uses a motor to drive a pump and transfer a fluid from a supply reservoir, such as a well, to a demand reservoir, such as a tank. A sensor measures a characteristic of the fluid, and a control unit controls operation of the motor. In some systems, the control unit measures a level of the fluid in a tank and controls operation of the motor to maintain the level within a range. When the level reaches the low end of the range, the control unit turns the motor on and keeps it on until the level reaches the high end of the range. In another system, the speed of the motor is controlled to maintain pressure within predetermined parameters. A variable speed loop controls the speed of the motor within a variable speed range to gradually increase or decrease the pumping rate and thereby maintain the pressure near the setpoint. Induction motors are frequently used in fluid supply systems.
Exemplary embodiments of a control system and method are provided herein. In one embodiment, the system comprises a drive unit including an enclosure including a cover and an enclosure body having an opening, the enclosure forming an enclosed space when the cover is positioned over the opening; a control unit positioned in the enclosed space, the control unit including application logic configured to control a load based on control parameters provided by a user with a user input device; and an internal wireless link configured to receive the control parameters, the internal wireless link positioned inside the enclosed space when the cover is positioned over the opening. The system further comprises a communication module located outside the enclosure and configured to establish a short-range wireless link with the internal wireless link, the communication module including a transceiver configured to establish communication with the user input device and receive the control parameters therefrom, and the communication module configured to communicate the control parameters to the internal wireless link with the short-range wireless link.
In variations of the present embodiment, the communication module is detachably coupled to the enclosure.
In variations of the present embodiment, the drive unit is configured to determine the presence of the communication module.
In variations of the present embodiment, the communication module comprises an external wireless link and a processing device, the external wireless link establishing the short-range wireless link with the internal wireless link. In one example, the short-range wireless link comprises one of an inductive and a capacitive wireless communication link. In another example, the control system further comprises a power circuit configured to generate power pulses and transfer energy to the external wireless link via the power pulses.
In one embodiment, the method comprises entering configuration parameters into a user input device, the configuration parameters configured to control a control unit adapted to power a load, the control unit located inside an enclosure; transmitting the configuration parameters with the user input device; receiving the configuration parameters with a communication module including an external wireless link and a processing device; transmitting the configuration parameters with the external wireless link to an internal wireless link located inside the enclosure; and configuring the control unit based on the configuration parameters.
In variations of the present embodiment, the method further comprises: detachably attaching the communication module to the enclosure.
In variations of the present embodiment, the method further comprises: detecting the presence of the communication unit, and preventing configuration of the control unit if the presence is not detected.
The foregoing embodiments and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.
Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of various features and components according to the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplification set out herein illustrates embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. As used herein, the terms “comprising” and “including” denote an open transition meaning that the claim in which the open transition is used is not limited to the elements following the transitional term.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings, which are described below. The embodiments disclosed below are not intended to be exhaustive or limit the invention to the precise form disclosed in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. It will be understood that no limitation of the scope of the disclosure is thereby intended. The invention includes any alterations and further modifications in the illustrated devices and described methods and further applications of the principles of the invention which would normally occur to one skilled in the art to which the invention relates.
Exemplary embodiments of a control system and a method are provided herein. A motor coupled to a pump is an exemplary load. Although embodiments described below may be described in the context of an electric motor driving a pump, the invention is no so limited and embodiments of the invention may be used to control any load coupled to a control unit. Other loads may include traction systems of vehicles, fans, extruders, rollers etc.
The disclosure provides wireless communication features. Benefits include providing isolated communications between a communication module located outside an enclosure and a control unit located in the enclosure to maintain the integrity of the enclosure, not burdening the control system with the cost of this feature when used on an intermittent basis, and the possibility of installation of the control system by a non-professional installer, as the installer will not be exposed to live voltages.
Furthermore, the communication module can be attached in a few seconds to the enclosure, without removal of any covers. The same communication module could work across a wide range of products having the supporting circuitry. The supporting circuitry may be substantially less expensive than a transceiver in the control module.
Even further, future obsolescence of the communication module is easily overcome since the communication module can be updated without modifying the control unit inside the enclosure. The range of a transceiver in the control module would not be impacted by the enclosure. A ¼ watt transceiver would have a range of 1000′ feet, for instance, but less if it were placed inside the enclosure. The communication module may also be NEMA 4 rated, for permanent installation, outdoors.
The communication features include means of coupling energy from within the enclosure (powering the communication module), means of communicating signals (transmit, receive, etc.), means to communicate through wireless signals (magnetically, optically etc., through electronic standards including WiFi and Bluetooth) and to switches and displays of the communications module or independent of the communications module.
The communication features also include means for detachably attaching the communication module to the enclosure. Exemplary attaching means include magnets, fasteners including hook-and-loop fasteners, clearance fits and any known means for detachably attaching components.
As discussed above, a fluid supply system, or pump system, is an example of a control system. Pump systems may be used, among other reasons, to fill tanks, maintain water pressure in a pipe, or pump liquids out of deep wells. Sensors and control switches may be coupled to a pump-motor assembly (“PMA”) to enable the drive unit to control the pumping rate. For example, an on/off switch may be used to turn the drive unit on and off. A level switch may be used to indicate to the drive unit when pumping is necessary to fill a tank and to indicate to the drive unit that the tank is full. A pressure transducer may be used by the drive unit to maintain fluid pressure in a pipe. Different pump types may be coupled to the motor, including centrifugal, positive displacement, reciprocating and any other pump types. PMA's may be purchased as a system or may be assembled by matching the requirements of the motor, the pump and the system application.
Renewable energy sources can be used to power PMAs subject to variations in the availability of said resources. Exemplary renewable energy sources include water, wind and solar. Different control schemes are needed to satisfy demand with renewable energy sources and compensate for or overcome such variations. For example, a control scheme to use solar energy in pumping applications may incorporate a maximum power point control strategy to maximize the amount of energy captured by photovoltaic panels at different insolation levels over time. When the solar energy is insufficient to pump the required amount of water, batteries or a fueled power generator may be connected to the drive unit to satisfy demand, either by supplementing the solar power captured by the photoelectric panels or as an alternate supply source. As used herein, a fueled power generator comprises a machine that converts fuel to electrical energy. Exemplary fuels include natural gas, propane, methane, kerosene, diesel and gasoline.
As exemplified above, drive units find utility in many applications and can be located in different environments, both indoors and outdoors. One of the challenges in building drive units to satisfy such complex requirements is to provide drive units that are adaptable to changing requirements and technologies. The wireless communication features facilitate communication with the drive unit to enable a user or technician to modify control parameters of the drive unit, update its control logic, and troubleshoot performance. Thus, for example, as new sensors or motors become available, control logic is improved, or the application's requirements change, the drive unit can be updated with a wirelessly communicatively coupled user input device to adapt to these and other changes. The wireless communication features have several advantages, including the capability to reduce the cost of the drive unit by excluding from it a complex user input interface, to improve protection of drive components by removing external components that may be susceptible to environmental degradation, and of course, a more flexible way to obtain the updates and bring them to the drive unit or to download from the drive unit performance parameters that can then be analyzed in a comfortable environment rather than at the drive unit's location.
Referring now to
Non-transitory machine readable medium 120 includes drive control parameters 122, and application logic 124. Power module 140 receives control signals from processing device 110 as instructed by application logic 124 to provide a suitable power signal to the motor. Power modules comprise power switches which are switched by motor control logic to generate appropriate power waveforms. Operation of power modules is well known in the art. Application logic 124 also includes logic configured to interface and/or control components of internal wireless link 130 such as a power circuit, a signaling circuit, a signaling circuit and an edge blanking circuit described with reference to
Also shown in
In one variation of the present embodiment, a user accesses support logic 162 to download drive application 156 into user input device 150. Support logic 162 may comprise HTML code well known in the art for enabling users to select features, download applications and perform typical functions performed by websites. After downloading, the user accesses drive application 156 in user input device 150 to communicate with drive unit 100. Drive application 156 may enable the user to change drive control parameters, download a logic update to update application logic, and/or retrieve performance parameters. Exemplary performance parameters include operating history of drive variables such as voltage, current, torque, speed, faults and other variables indicative of the performance of drive unit 100. Drive application 156 may also enable the user to select configuration information including a system application and a motor identifier.
A user may access drive application 156 to communicate with support logic 162 and download a logic update (to update application logic 124) into user input device 150. User input device 150 then establishes communications with drive unit 100 and downloads logic update to drive unit 100. The user can download the update to user input device 150 by accessing the Internet and then, perhaps at a different location, establishing communications with drive unit 100. Drive application 156 may provide options to the user to initiate communication with drive unit 100.
Wireless communication features include any known or future developed communication technique or protocol, including inductive (near and far field), capacitive, infrared, optical and radio-frequency technologies, and Wi-Fi, ZigBee and Bluetooth protocols. The Wi-Fi protocol is a wireless local area network protocol based on the IEEE 802.11 standard. Devices using Wi-Fi can connect to the Internet. ZigBee is based on the IEEE 802.15 standard, a protocol to create personal area networks. Bluetooth is another personal area network protocol, and is based on the IEEE 802.15.1 standard. The aforementioned wireless protocols may be used by a communication module and user input device 150 to communicate with each other. User input device 150 may also have a Wi-Fi or a cellular communications interface to connect to the Internet.
Referring to
The communication module may also function as a user interface. In one embodiment, a detector circuit is operable to detect movements of the communication module relative to the enclosure. Exemplary depictions of a detector circuit are described with reference to
It may be desirable to prevent unauthorized access to the control system. In one embodiment, the communication module and the internal wireless link “handshake” to confirm that an authorized communication module is being used. Handshaking may include signaling patterns by one or the other or both wireless links in a predetermined arrangement. Unless the handshake is successful, the control unit will not accept configuration changes. Handshaking also prevents misinterpretation of noise as signals. Of course, the control unit will continue to control the load when the communication module is removed.
In one embodiment, the control system is configured to temporarily mount communication module near internal wireless link 130 with cover 380 open. Such configuration is desirable to enable a technician to work on drive unit 100. A bracket, magnets or other suitable attachment features may be provided on control unit 112 to support communication module 130.
Energy storage 328 may be charged through the short-range wireless link. In one example, magnetic coupling is provided through non-ferrous metal section 312, as described below with reference to
Power circuit 340 comprises a switch, illustratively a MOSFET switch, energized by a processor output in power pulses of short durations to couple a coil 348 to a high voltage DC source, illustratively 17 VDC. The power pulse durations are short relative to their periodicity. Between the power pulses, communication pulses are transmitted with coil 348 and signals from a coil 338 are detected. A snubber circuit, shown as a zener diode across coil 348, allows any leakage flux that is not coupled to coil 338 to collapse quickly, allowing a long interval without noise disturbances. A series blocking diode is provided so when the transistor is on, the snubber circuit is not conducting. Then, when the transistor turns off, the leakage flux is collapsed through the path of the zener diode and blocking diode (now conducting).
Power collector 330, illustratively a rectified DC voltage with the combination of a rectifier diode and bulk capacitor, captures energy transferred with the inductive coupling formed by coils 338 and 348, having a ratio of N:1. An exemplary ratio is 2:1.
Each of detector circuits 332 and 342 are configured to monitor the impressed voltages in coils 338 and 348 with a processor input. Resistors and a zener diode may be provided to protect the processor input. Information is synchronized with respect to the power pulses, described above, and transmitted and received in the gaps between power pulses.
Each of signaling circuits 334 and 344 are configured to convert a processor output to a low voltage suitable to energize corresponding coils 338 and 348. An exemplary push/pull block is shown. Exemplary push/pull blocks may comprise a half-bridge transistor circuit, an open emitter, and/or an open collector transistor. These circuits are often incorporated in microprocessors and can also be provided as discrete circuits.
Voltages applied to the coils are switched between high voltages, to induce power transfer, and low voltages, to communicate. The actual levels of the high and low voltages are determined by the component selection and the construction of the modules. To conserve energy, communications are desirable using the least power, in which case low voltages are the voltages sufficient to establish communications by generating sufficient flux to overcome the air gap. By contrast, high voltages are voltages in excess of the voltage level necessary to communicate, and where the excess power can be effectively coupled.
Edge blanking circuits 336 and 346 are configured to protect the microprocessor and are synchronized to the power pulses, at the timed interval of the power pulse. Alternative protection circuits include low pass filters, voltage dividers, zener clamps.
In one embodiment, an internal wireless link transmits a detection signal and senses a response thereto, a “presence signal”, indicative of the presence of the external wireless link. Responsive to the presence of the communication module, the internal wireless link operates in a first mode to charge the energy storage of the external wireless link. It then switches to a second mode to begin communications. In the second mode, communication signals are transmitted alone or synchronized with power pulses. In one variation, power pulses are transmitted at a first frequency in the first mode, to accelerate charging of the communication module, and at a second frequency in the second mode, to maintain the charge of the communication module, the first frequency being higher than the second frequency. In another variation, the external wireless link detects a state of charge and sends a charge indication signal to indicate to the internal wireless link that it is sufficiently charged. Responsive to the charge indication signal, the internal wireless link enters the second mode. The state of charge may be the voltage of the bulk capacitor.
The internal wireless link may transmit the detection signal periodically. For example, the detection signal may be transmitted every 500 milliseconds or every second. In a variation of the present embodiment, detection logic is provided to detect the presence of the communication module. Detection logic may comprise a capacitive switch or a reed switch on the cover that generates the presence signal. Any known detection circuits may be used. Detection logic may also detect movement of a magnet in the communication module over a given location in the cover. The internal wireless link may not begin generating power pulses or information signals until the presence is detected. The detection logic may also detect when the communication module is not present and cause the internal wireless link to cease generating signals. Of course, if the communication module is tethered or includes a battery, it may transmit a presence signal and the internal wireless link merely waits for the presence signal instead of periodically transmitting detection signals.
Additional features may be provided based on the above disclosure. In one embodiment, components described above are utilized by control unit 112 to detect the presence of the cover. If the cover is removed, the product may automatically shut down or enunciate an error. The cover may be detected by detecting the level of leakage flux, where a high leakage flux indicates the lid is not present. Detector circuit 342 may be used to detect a ferrous metal cover, for example. In another example, a module comprising ferrous metal, perhaps the magnetic core of the external wireless link, may be permanently attached to the cover, without the coil, to facilitate its detection.
As used herein, processing instructions include a single application, a plurality of applications, one or more programs or subroutines, software, firmware, and any variations thereof suitable to execute instruction sequences with a processing device.
As used herein, a processing or computing system or device, may be a specifically constructed apparatus or may comprise general purpose computers selectively activated or reconfigured by software programs stored therein. The computing device, whether specifically constructed or general purpose, has at least one processing device, or processing device, for executing processing instructions and computer readable storage media, or memory, for storing instructions and other information. Many combinations of processing circuitry and information storing equipment are known by those of ordinary skill in these arts. A processing device may be a microprocessor, a digital signal processor (“DSP”), a central processing unit (“CPU”), or other circuit or equivalent capable of interpreting instructions or performing logical actions on information. A processing device may encompass multiple processors integrated in a motherboard and may also include one or more graphics processors and embedded memory. Exemplary processing systems include workstations, personal computers, portable computers, portable wireless devices, mobile processing devices, and any device including a processor, memory and software. Processing systems also encompass one or more computing devices and include computer networks and distributed computing devices.
As used herein, a non-transitory machine readable storage medium comprises any medium configured to store data, such as volatile and non-volatile memory, temporary and cache memory and optical or magnetic disk storage. Exemplary storage media include electronic, magnetic, optical, printed, or media, in any format, used to store information. Computer readable storage medium also comprises a plurality thereof.
Unless otherwise expressly stated in connection with a specific use thereof, the term “device” includes a single device, a plurality of devices, two components integrated into a device, and any variations thereof. The singular form is only used to illustrate a particular functionality and not to limit the disclosure to a single component. Therefore, the term “memory device” includes any variation of electronic circuits in which processing instructions executable by a processing device may be embedded unless otherwise expressly stated in connection with the specific use of the term. For example, a memory device includes read only memory, random access memory, a field programmable gate array, a hard-drive, a disk, flash memory, and any combinations thereof, whether physically or electronically coupled. Similarly, a processing device includes, for example, a central processing unit, a math processing unit, a plurality of processors on a common integrated circuit, and a plurality of processors operating in concert, whether physically or electronically coupled. Furthermore and in a similar manner, the term “application,” in the context of an algorithm or software, includes a single application, a plurality of applications, one or more programs or subroutines, software, firmware, and any variations thereof suitable to execute instruction sequences with a processing device.
While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.
The present application claims the benefit of priority from commonly owned U.S. Provisional Patent Application No. 61/846,729, filed Jul. 16, 2013, and U.S. Provisional Patent Application No. 61/874,203, filed Sep. 5, 2013, the disclosure of said applications incorporated herein by reference in their entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US14/46820 | 7/16/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61846729 | Jul 2013 | US | |
| 61874203 | Sep 2013 | US |
