Patent Application
20240080678
The present invention relates to industrial process control or monitoring systems. More specifically, the present invention relates to wireless process field devices used in such systems which has a plurality of transceivers configured to send and/or receive information with a remote device.
In industrial settings, systems are used to monitor and/or control inventories and operation of industrial and chemical processes, and the like. Typically, the system that performs these functions uses field devices distributed at key locations in the industrial process which couple to control circuitry in a control room through a process control loop. The term “field device” refers to any device that performs a function in a distributed process control or process monitoring system, including all devices used in the measurement, control and monitoring of industrial processes.
Typically, each field device also includes communication circuitry that is used for communicating with a process controller, other field devices, or other circuitry, over the process control loop. In some installations, the process control loop is also used to deliver a regulated current and/or voltage to the field device for powering the field device. The process control loop also carries data, either in an analog or digital format.
In some installations, wireless technologies have begun to be used to provide the process control loop and communicate with field devices. Wireless operation simplifies field device wiring and setup. There is an ongoing need for improved wireless communication in industrial field devices.
A wireless industrial process field device includes a process interface element configured to interface with a process fluid and control or sense a process variable of the process fluid. A controller is configured to control operation of the process interface element. An RF circuit board includes a plurality of RF transceivers carried on the RF circuit board, each configured to send and/or receive an RF signal which carries information related to the process variable. A plurality of antennas are carried on the RF circuit board and form an antenna array. Each of the plurality of antennas is coupled to at least one of the plurality of RF transceivers. Each of the plurality of antennas having a different antenna pattern. The controller controls operation of the plurality of RF transceivers to communicate with a remote device by transmission of RF signals through the plurality of antennas.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. The claimed subject matter is not limited to implementations that solve any or all disadvantages noted in the Background.
Embodiments of the present disclosure are described more fully hereinafter with reference to the accompanying drawings. Elements that are identified using the same or similar reference characters refer to the same or similar elements. Some elements may not be shown in each of the figures in order to simplify the illustrations.
The various embodiments of the present disclosure may be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.
As discussed in the Background section, industrial process field devices are used to control and monitor process variables, for example of process fluids, in industrial processes. Example process variables that can be measured or controlled include flow, level, temperature, etc. In some instances, the field devices are configured to operate wirelessly. Wireless communication in industrial processes can be difficult due to power constraints, interfering electrical and RF (radio frequency) signals, obstacles blocking communication paths, among other reasons. One technique used to address these issues is the use of multiple radio transceivers implemented in field devices for communicating with remote devices over more than one RF communication link. One such technique is generally referred to as multi-core radio technology which is described in U.S. Pat. No. 10,165,531, issued Dec. 25, 2018, entitled TRANSMISSION AND RECEPTION OF SIGNALS IN TIME SYNCHRONIZED WIRELESS SENSOR ACTUATOR NETWORK and U.S. application Ser. No. 17/699,169 (US Publication No. 2022/0311584), filed on Mar. 21, 2022 and entitled RF ADAPTIVE DIVERSITY AND METHOD FOR MAXIMIZING CAPACITY IN A WIRELESS TRANSMISSION which are incorporated herein in their entirety.
In various aspects, the present invention provides a wireless industrial process field device which includes a process interface configured to interface with the process fluid and control or sense (measure) a process variable of the process fluid. A controller such as a microprocessor is configured to communicate with the process interface element and thereby sense the process variable using the process interface or control the process variable using the process interface. The wireless field device includes an RF circuit board which includes a plurality of RF transceivers as well as a plurality of antennas. The RF circuit board is arranged in such a way that the antennas can wirelessly communicate to remote devices. For example, the RF circuit board can be placed in an RF transparent radome or other such structure, for example outside of a housing of the wireless industrial process field device. Each of the plurality of antennas is each coupled to at least one RF transceiver. Each of the plurality of antennas has a different antenna pattern due to the configuration and/or orientation of the individual antenna. The controller is configured to communicate with remote devices through one or more of the transceiver/antenna pairs which can be selected based upon the quality, reliability, or some other characteristic of the communication link. Further, the various transceivers/antenna pairs can be used to communicate using multiple different communication protocols to allow communication with different types of wireless devices.
Another process field device 130 is configured as a variable transmitter and couples to a process interface element configured as a level switch 132. The level switch 132 is another example of process variable sensor and is configured to actuate based upon the level of process fluid 108 in tank 106. Process variable transmitter 130 includes an antenna 134 for communicating with remote devices. The RF communication link can be used to transmit information related to the sensed level of the process fluid 108 as well as diagnostic information or other information. Further, this RF communication link can be used to receive configuration commands, software updates, or other instructions or commands.
A central location such as a control room is configured as a controller/monitor station 140 of the industrial process 100. Control/monitor station 140 includes antenna 142 for use in communicating with process field devices 110, 120 and 130. The station 140 can receive the sensed process variables from process variable transmitters and responsively transmit control commands to process control devices to control operation of the industrial process. This allows the sensed process variables to provide feedback for a control system. The station 140 can also receive or otherwise provide alarms based upon received process variables or diagnostic information, and can send out commands or other instructions to the various different types of process field devices. Alternatively, a gateway (not shown) may be used to communicate with the field devices, with the gateway then communicating (wired or wireless) with the control/monitor station.
The various RF communication links 160-168 illustrated in
As discussed in the Background section, the use of multiple transceivers provides a platform to enhance reliability and functionality for industrial process communications. For example, by using multiple radio transceivers, the system can be configured to be less susceptible to interference from other RF communication links and is better able to coexist in a crowded RF spectrum. The use of additional radios can also allow for an extended communication range by selecting or coordinating between the various transceivers, as well as increased network capacity and higher data rates. Because multiple communication links and configurations are available to a device, it is possible to select the one which requires the least amount of power for a particular level of reliability and signal quality. This allows lower power utilization, which can be significant in wireless devices which do not have a connection to an external power source. The multiple different RF communication links and configurations can also be used to determine or validate the health of a particular communication link. For example, redundant data can be communicated on multiple links to determine which link provides the most desirable link characteristics. Using multiple transceivers, as discussed above, it is also possible for different devices to communicate using different RF communication techniques and frequencies.
These enhancements are enabled by radio redundancy and optimization schemes to sense the environment and adapt to the device's surroundings. Specific implementations of process field devices with multiple transceiver technology in wireless industrial applications are discussed herein.
Existing industrial wireless systems, may be adequate for some current applications, but with the increasing deployment of wireless products. However, improved levels of reliability and performance as may be required by industrial applications is desirable.
Coexistence in the RF spectrum becomes difficult with the congestion caused by the deployment of a large number of wireless sensors and actuators in a shared RF space. Competing wireless traffic can also come from higher power signaling products such as Wi-Fi. This can cause lower power wireless devices to be susceptible to dropping off the network or missing messages. Wireless congestion will only become a larger problem over time with more wireless applications.
Transmit power for wireless communication is a significant part of the power consumption of a process field device (or “field node”) Typical wireless systems use fixed transmit power to ensure communication reliability regardless of the RF environment. When the environment is not congested and does not require high power for successful transmission, the excess transmission power is wasted, leading to an unnecessarily short battery life. Further, higher transmit power also has the potential to interfere with other nearby users of the shared RF spectrum, which may include other members of the same communication network.
Longer range communication is also desirable as this allows for more remote applications with fewer repeaters/devices needed between the field devices. At longer distances, wireless packets will be lost and eventually the field node will drop off the network. A configuration with multiple transceivers can be used to select more efficient communication links and thereby extend the communication range.
Network capacity is limited with increasing update rates. As the update rate increases (e.g., 1 update per second), the maximum number of field nodes in the network must be decreased. This makes fast update rates on large networks expensive and less desirable. Further, large data packets take significant time to transmit through a mesh network. Again, using multiple transceivers, a more efficient link configuration can be selected to help offset this capacity limitation.
Dynamic sensing of the RF environment typically cannot be performed in single-radio systems without disrupting the primary communication channel. RF characteristics can change with the environment, making the system less efficient and can significantly impact other nodes in the network. However, with multiple RF communication links, one or more of the links can be used for performing diagnostics and determining RF communication characteristics while one or more other links may be used for communicating system data.
Configuration and calibration through a mesh network can take a significant amount of time depending on the number of field nodes messages that need to pass through. Further, directly interacting with a device through a maintenance port requires direct physical connection which is inconvenient, especially when the field node is located in a hazardous area. Using multiple communication links, one or more of the links can be used for maintenance and configuration without interrupting communication on other data communication links
Propagation delay between field nodes may be a significant factor in limiting the amount of data that can be communicated and the speed at which the system can react. For example, a wireless controller may take too long to react to a data event through a mesh network. An example is triggering a remote (wireless) actuator based on a measurement from another field device. Using multiple communication links, this propagation delay between field nodes can be reduced and, in some instances, a direct communication link between nodes can be provided.
The use of multiple transceivers can be used to provide redundant communication paths. This will enable wireless devices to evolve with the changing environment of wireless connectivity by improving reliability, performance, and functionality.
Multiple transceivers incorporate two or more embedded independent but coordinated radios to enhance existing communication protocols. These radios are referred herein as “transceivers”. Although a transceiver typically refers to a device which is bidirectional and capable of both receiving and transmitting data, as used herein “transceiver” also refers to RF communication circuitry which can only receive or only transmit data. These radios can be used to assess the RF environment while standard communication is in process. The information gained through this environmental assessment can be used to adjust communication parameters without interfering with the underlying communication protocol. The behavior of the radios can be adjusted depending on the environment to preserve range and reliability in a crowded RF spectrum, or to save power and increase capacity in clean RF environments.
Network capacity and data throughput can also be improved with the multiple transceivers by simultaneously receiving or transmitting messages to and from multiple field nodes or other wireless devices. For example, one or more communication links can be used for transmitting data while simultaneously one or more other communication links can be utilized for receiving data.
The inherent redundancy of multiple transceivers can be used to enhance mission-critical safety instrumented system (SIS) applications where data reliability is critical. Among other things, the use of multiple transceivers enables the implementation of a voting scheme to determine the “best” communication parameters (e.g., timing, channel, antenna, etc.) to use to ensure data reliability.
Multiple transceivers can also be used to independently assess the health of various parts of the wireless communication system (RF connections, antennas, channels, paths, temporal impairments, etc.). A signal is transmitted by one radio and received by one or more other radio of the same multi transceiver device in order to conduct a health assessment of the signal path. A relative comparison can then be conducted between transceivers and between current performance and a performance signature captured during manufacturing, commissioning, or at some other point or points in the past. These comparisons are used to assess signal path characteristic changes and their impact on communication performance, including component degradation and drift or environmental effects. The collected signal path quality information can be used dynamically to maintain the “best” possible performance (e.g., do not use transceivers that have degraded performance) and can be communicated to the user, so the node can be repaired or replaced.
Bluetooth® technology is used today as a method to configure and collect data directly from wired HART® technology and other industrial products without a physical direct connection. Interaction between a WirelessHART® technology field node and a configurator or calibrator can be improved by using one transceiver as a local configuration interface using a local communication standard (e.g., Bluetooth® technology). This will allow configuration activities without affecting the primary communication channel (e.g., WirelessHART® technology) since both protocols could be active simultaneously. This allows for convenient configuration of the field node before it is connected and authenticated into the primary communication network. The same concept can be used to enable over-the-air firmware updates without interrupting the primary communication channel.
Similarly, multiple point to point wireless field channels can be utilized to ‘share’ information with neighboring field nodes or other devices (e.g., a wireless handheld device) to improve speed of control or reactions while still maintaining a connection to the primary communication network. The shared data can be used for triggering actuators quickly based on a measurement made in another field node. Another example is using the shared data in an augmented reality overlay for products to quickly provide the user with measurements or status when looking at the field node. For example, a real time or stored image or schematic representation of system 100 can be displayed on display 154 of configuration device 150 along with the status or measurement data. Other display techniques or technologies may also be implemented.
Implementation of multi transceiver technology into practical and economical field nodes is complicated by the need to attach multiple antennas. Typically, antenna connections in such devices are made using expensive coaxial cables or tuned copper strip lines on printed circuit boards. One means of efficiently connecting antennas to a plurality of transceivers is to deploy the radio transceivers on the same circuit board (PCB) substrate as the antennas. For example, mounting both the transceivers and the antennas in the form of integrated circuit chips, stamped metal, copper circuit board features or other types of components on a circuit board located within an RF transparent radome. This also enables a low-cost implementation in existing wireless field nodes that are constructed of conductive materials and have external RF transparent radomes.
During operation, controller 204 of field device 200 is able to communicate with remote devices using transceiver system 210 communicating through antennas 214. The various features and configurations discussed above can be implemented by communicating using different transceivers and antennas. The controller 204 can transmit a process variable sensed by process interface 212 and received through an analog to digital converter 202 using a transceiver 212-1. The same process variable can be redundantly transmitted using a second transceiver. In another example, a second transceiver such as transceiver 212-2 is used to communicate with another field device, for example configuration unit 150. In such a configuration, process variable or control information can be communicated using, for example, WirelessHart® technology to a remote field device or station 140. At the same time, transceiver 212-2 can communicate with configuration device 150 using a more local communication technique, such as Bluetooth® technology. While communicating over other transceivers, field device 200 can utilize transceiver 212-N to communicate with another remote device, or the same remote device, in order to evaluate characteristics of the communication link such as signal strength, data loss, etc. This allows the controller 204 (or radio system 210) to select the “best” communication link based upon a predetermined set of communication requirements.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. The controller can be implemented by, for example, a microprocessor or other device. The antennas 214 provide an antenna pattern based on their configuration and orientation. Multiple transceiver/antenna pairs can be used to generate an antenna array pattern which is formed based upon the individual antenna patterns generated by each antenna. For example, this allows the antenna array pattern to be altered or “steered” electronically during operation of the device.
The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 63/400,784, filed Aug. 25, 2022, the content of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63400784 | Aug 2022 | US |
