Patent Application
20140018015
The embodiments disclosed herein relate generally to a transport refrigeration system. More particularly, the embodiments relate to preserving the power source life of a wireless end node prior to deployment in a wireless communication system for use in a mobile environment, such as a transport refrigeration system.
Existing transport refrigeration systems are used to cool containers, trailers, and other similar transport units (typically referred to as a “reefer”). Modern reefers may be efficiently stacked for shipment by ship or rail. Typically, when reefers are shipped by truck, a single reefer is placed on a trailer chassis. When cargo in the container includes perishable products (e.g., food product, flowers, etc.), the temperature of the reefer must be controlled to limit loss of the cargo during shipment.
The embodiments described herein are directed to preserving the power source life of a wireless end node prior to deployment in a wireless communication system for use in a mobile environment, such as a transport refrigeration system.
In one embodiment, a method for preserving the power source life of a wireless end node prior to deployment in a wireless communication system is provided. The method includes operating the wireless end node in a long term storage mode prior to deploying the wireless end node in a wireless communication system in order to reduce current being drawn from a power source of the wireless end node. The method also includes the wireless end node detecting an interrupt request to pair the wireless end node to a wireless communication system. Also, the method includes the controller of the wireless end node switching from a long term storage mode to a normal operation mode when the wireless end node is paired to a wireless communication system.
In yet another embodiment a wireless end node for use in a wireless communication system is provided. The wireless end node includes a power source and an electrical assembly connected to the power source. The electrical assembly includes a controller configured to manage, command, direct and regulate the behavior of the wireless end node and configured to switch operation of the wireless end node between a long term storage mode that reduces current being drawn from the power source and a normal operation mode. The controller includes a sleep timer configured to count down a long term storage time period. The controller is configured to operate the wireless end node in the long term storage mode prior to deploying the wireless end node in a wireless communication system and is configured to switch from the long term storage mode to the normal operation mode when the wireless end node is paired to the wireless communication system.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout.
The embodiments described herein are directed to preserving the power source life of a wireless end node prior to deployment in a wireless communication system for use in a mobile environment, such as a transport refrigeration system.
References are made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration of the embodiments in which the methods and systems described herein may be practiced. The term “reefer” generally refers to, for example, a temperature controlled trailer, container, or other type of transport unit, etc. The term “wireless communication system” refers to a communication system that is configured to transmit data over a short distance in a mobile environment, such as, for example, between different points of a reefer that is in transport. The term “wireless end node” refers to an electronic device that is an endpoint of a wireless communication system and is capable of monitoring a property of a temperature refrigeration system and transmitting data transmissions to and receiving data transmissions from a network coordinator of the wireless communication system. The term “network coordinator” refers to an electronic device that is configured to manage, command, direct and regulate the behavior of one or more wireless end nodes of the wireless communication system. The term “deployment” refers to a wireless end node being paired to a wireless communication system and installed in a transport refrigeration system.
It will be appreciated that the embodiments described herein are not limited to trucks and trailer units. The embodiments described herein may be used in any other suitable temperature controlled apparatuses such as a ship board container, an air cargo cabin, an over the road truck cabin, etc. The refrigeration system may be a vapor-compressor type refrigeration system, or any other suitable refrigeration systems that can use refrigerant, cold plate technology, etc.
The transport refrigeration system 110 includes a wireless communication system 140 and a fuel tank 145. The wireless communication system 140 includes a network coordinator (not shown), an antenna 150, and a plurality of wireless end nodes 155. As shown in
Referring to
In some embodiments the network coordinator 210 is a WPAN module that is configured to be installed in a control box (not shown) of a transport refrigeration system. The network coordinator 210 is configured to transmit to and receive data from each of the plurality of wireless end nodes 220 via the antenna 215 using a short distance wireless communication protocol such as, for example ZigBee, Bluetooth, etc. Also, the network coordinator 210 is configured to connect to a control unit of a transport refrigeration system stored in the control box.
The antenna 215 is a weatherproof antenna that is configured to be installed outside of the control box and is connected to the network coordinator 210 via a wired communication link 212 such as, for example, a coaxial cable. In some embodiments, the antenna 215 can be configured to be installed inside the control box with the network coordinator 210.
Each of the plurality of wireless end nodes 220 is configured to transmit and receive information with the network coordinator 210 using a short distance wireless communication protocol such as, for example ZigBee, Bluetooth, etc. In some embodiments, one or more of the wireless end nodes 220 are weatherproof by using a sealed housing (not shown) to prevent failure due to water ingress, extreme temperatures, UV exposure, exposure to oil/solvents, etc.
Each of the plurality of wireless end nodes 220 can be, for example, a door sensor, a fuel tank temperature sensor, an air space temperature sensor, a humidity sensor, a cargo temperature center, etc. When the wireless end node 220 is a door sensor, the wireless end node 220 is configured to transmit a data signal to the network coordinator 210 when a door of the transport refrigeration system being monitored by the wireless end node 220 is opened or closed. When the wireless end node 220 is a fuel tank temperature sensor, the wireless end node 220 is configured to transmit a data signal to the network coordinator 210 indicating the temperature of a fuel tank of a transport refrigeration system. When the wireless end node 220 is an air space temperature sensor, the wireless end node 220 is configured to transmit a data signal to the network coordinator 210 indicating the temperature of an internal space of a reefer. When the wireless end node 220 is a humidity sensor, the wireless end node 220 is configured to transmit a data signal to the network coordinator 210 indicating the humidity of an internal space of a reefer. When the wireless end node 220 is a cargo temperature sensor, the wireless end node 220 is configured to transmit a data signal to the network coordinator 210 indicating the temperature of cargo stored in the reefer.
For transport refrigeration systems, the housing 330 must satisfy vigorous environmental sealing requirements for the wireless end node 300 to be acceptable for use. Accordingly, once the wireless end node is manufactured, the electrical assembly and the power source are not serviceable and any feature within the housing that can penetrate to the outside of the housing could be considered a possible failure point.
The electrical assembly 310 includes a controller 340, an operating sensor 345, a transceiver 350, a memory storage 355, and a light emitting diode (LED) light 360. The controller is provided to control the wireless end node 300 and includes a sleep timer 365.
The controller 340 is configured to manage, command, direct and regulate the behavior of the wireless end node. Also, the controller 340 is configured to direct the wireless end node 300 to operate in a long term storage mode prior to deployment of the wireless end node 300 in a wireless communication system and a normal operation mode and a sleep mode upon deployment in a wireless communication system. In the normal operation mode, the electrical assembly 310 draws current from the power source 320, the operating sensor 345 can monitor a portion of the transport refrigeration system, the transceiver 350 can transmit data to and receive data from the network coordinator of the wireless communication system. In the sleep mode, the electrical assembly is powered down to reduce the amount of current drawn from the power source. During the sleep mode, sufficient current is drawn from the power source 320 to allow the sleep timer 365 to count down an amount of time to indicate to the controller 340 when the wireless end node 300 should switch to the normal operation mode and monitor an interrupt request from a user or the network coordinator of the wireless communication system. Also, sufficient current is drawn from the power source 320 to switch the wireless end node 300 from the sleep mode to the normal operation mode when an interrupt request is received or when the sleep timer indicates to the controller 340 to switch to the normal operation mode.
Similar to the sleep mode, in the long term storage mode the electrical assembly is powered down to reduce the amount of current drawn from the power source. During the long term storage mode, sufficient current is drawn from the power source 320 to allow the sleep timer 365 to count down an amount of time to indicate to the controller 340 when the wireless end node 300 should power up to measure a power source level of the power source 320 and to monitor an interrupt request from a user to deploy the wireless end node 300 to a wireless communication system. Also, sufficient current is drawn from the power source 320 to power up the wireless end node 300 when an interrupt request is received or when the sleep timer indicates to the controller 340 to measure the power source level of the power source 320.
The operating sensor 345 is connected to the controller 340 and performs a sensing operation for the transport refrigeration system. For example, if the wireless end node 300 is a door sensor, the operation sensor 345 can sense when a door that is being monitored by the wireless end node 300 is opened or closed and can notify the controller 340 of this information. If the wireless end node 300 is a fuel tank temperature sensor, the operation sensor 345 can measure the temperature of a fuel tank of a transport refrigeration system and can notify the controller 340 of this information. If the wireless end node 300 is an air space temperature sensor, the operation sensor 345 can measure the temperature of an internal space of a reefer and can notify the controller 340 of this information. If the wireless end node 300 is a humidity sensor, the operation sensor 345 can measure the humidity of a reefer and can notify the controller 340 of this information. If the wireless end node 300 is a cargo temperature sensor, the operation sensor 345 can measure the temperature of cargo stored in a reefer and can notify the controller 340 of this information.
The transceiver 350 is also connected to the controller 340 and is configured to transmit to and receive data signals from a network coordinator of a wireless communication system. For example, if the wireless end node 300 is a door sensor, the transceiver 350 can receive an acknowledgement message from the network coordinator to indicate that the wireless communication system is for use in a normal operation mode, and can send a sensing message to the network coordinator when the door being monitored by the wireless end node 300 is opened or closed. The transceiver 350 is configured to transmit and receive data using a short distance wireless communication protocol such, for example, ZibBee, Bluetooth, etc.
The memory storage 355 is connected to the controller 340 and can store information such as an acceptable power source level threshold. The memory storage 355 can also store information such as, for example, the information provided in the table below:
The LED light 360 is connected to the controller 340 and is visible outside of the sealed housing 330. The LED light 360 can be a multi-colored and blinking LED light that is visible to a user of a transport refrigeration system and can be used for pairing the wireless end node 300 to a wireless communication system and for communicating diagnostic information about the wireless end node 300. In one embodiment, the LED light 360 can blink red to indicate to a user that the power source life of the power source 320 is no longer acceptable for deployment in a wireless communication system.
The power source 320 can be a native 3.6 volt Li—SOCl2 battery. In other embodiments, the power source 320 can be a lithium based battery (e.g. a lithiumion battery, a lithium/Iron Disulfide (LiFeS2) battery, etc.).
The flowchart 400 begins at 405. At 410, a wireless end node is manufactured. In some embodiments, the wireless end node is manufactured such that the controller, the operation sensor, the power source and the memory storage are encapsulated in a sealed housing.
At 415, when the wireless end node is manufactured the controller is set to operate in a long term storage mode 420 until the wireless end node is paired to a wireless communication system.
The long term storage mode 420 is now described. At 425, the wireless end node uses the sleep timer in the controller to set a long term storage time period that the wireless end node remains in the long term storage mode. The long term storage time period of the sleep timer can be set by the manufacturer to a time limit that allows the wireless end node to provide accurate power source level information regarding the power source of the wireless end node while preventing excessive use of the power source that can drain lifespan of the wireless end node. In one embodiment, the long term storage time period of the sleep timer can be set to, for example, approximately 24 hours.
At 430, the wireless end node powers up after the long term storage time period set in the sleep timer lapses. At 435, the controller measures the voltage of the power source. Based on the measured voltage, at 440, the controller determines whether the power source life of the wireless end node is above an acceptable power source life threshold. In one embodiment, the acceptable power source level threshold is ˜2.9 volts for a native ˜3.6 volt battery. However, in other embodiments, the acceptable power source level threshold can be set at the manufacturer's discretion. If the power source life of the wireless end node is above the acceptable power source life threshold, the long term storage mode 420 returns to 425. If the power source life of the wireless end node is not above the acceptable power source life threshold, the wireless end node exits the long term storage mode 420 and the process 400 proceeds to 445.
At 445, the wireless end node indicates to the user that the power source life of the wireless end node is no longer acceptable for use. For example, in one embodiment, the LED light of the wireless end node blinks a red light when the power source life of the wireless end node is no longer acceptable for use.
The process 400 also includes an interrupt routine mode 450. The interrupt routine mode 450 begins at 455 when the wireless end node receives an interrupt message. In some embodiments, the interrupt message is sent to the wireless end node via a magnet swipe. In other embodiments, the interrupt message is sent to the wireless end node via a button press or a resistive float. At 460, the controller of the wireless end node determines whether the wireless end node is paired to a wireless communication system and installed in a network coordinator a transport refrigeration system for a reefer. If the controller determines that the wireless end node is not paired to the wireless communication system, the process 400 proceeds to the long term storage mode 420. If the controller determines that the wireless end node is paired to the wireless communication system, the process 400 proceeds to 465.
At 465, the controller determines that the wireless end node has been deployed and sets the wireless end node into a normal operation mode. The process 400 then proceeds to 470. At 470, the controller checks periodically, for example, once a day, whether the wireless end node has been decommissioned from the wireless communication system. If the controller determines that that the wireless end node has not been decommissioned, the process 400 returns to 465. If the controller determines that the wireless end node has been decommissioned, the process 400 returns to 415.
It is noted that any of aspects 1-7 below can be combined with any of aspects 8-14 and any of aspects 15-21. Also, any of aspects 8-14 can be combined with any of aspects 15-21.
1. A method for preserving the power source life of a wireless end node prior to deployment in a wireless communication system comprising:
operating the wireless end node in a long term storage mode prior to deploying the wireless end node in a wireless communication system in order to reduce current being drawn from a power source of the wireless end node;
the wireless end node detecting an interrupt request to pair the wireless end node to a wireless communication system;
a controller of the wireless end node switching from a long term storage mode to a normal operation mode when the wireless end node is paired to a wireless communication system.
2. The method of aspect 1 further comprising:
during the long term storage mode, powering the controller of the wireless end node after a sleep timer of the wireless end node determines a long term storage time period has lapsed to determine a power source level of a power source of the wireless end node;
the controller determining the power source level of the power source;
the controller comparing the power source level of the power source to an acceptable power source level threshold stored in a memory storage of the wireless end node; and
indicating a low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
3. The method of aspect 2, wherein the long term storage time period is 24 hours.
4. The method of aspects 2-3, wherein the acceptable power source level threshold is 2.9 volts for a 3.6 volt battery.
5. The method of aspects 2-4, blinking a red color light emitting diode light of the wireless end node to indicate the low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
The method of aspects 1-5, further comprising:
the controller determining whether the wireless end node is decommissioned from the wireless communication system; and
the controller setting the wireless end node to operate in the long term storage mode when the controller determines that the wireless end node is decommissioned from the wireless communication system.
7. The method of aspect 6, wherein the controller determines whether the wireless end node is decommissioned from the wireless communication system every 24 hours.
8. A wireless end node for a wireless communication system comprising:
a power source;
an electrical assembly connected to the power source, the electrical assembly including:
wherein the controller is configured to operate the wireless end node in the long term storage mode prior to deploying the wireless end node in a wireless communication system and is configured to switch from the long term storage mode to the normal operation mode when the wireless end node is paired to the wireless communication system.
9. The wireless end node of aspect 8, wherein the electrical assembly further includes a memory storage,
wherein, when the wireless end node is operating in the long term storage mode and the sleep timer of the wireless end node counts down the long term storage time period, the controller is configured to power up, determine the power source level of the power source, and compare the power source level of the power source to an acceptable power source level threshold stored in the memory storage, and
wherein the wireless end node is configured to indicate a low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
10. The wireless end node of aspects 8-9, wherein the long term storage time period is 24 hours.
11. The wireless end node of aspects 9-10, wherein the acceptable power source level threshold is 2.9 volts for a 3.6 volt battery.
12. The wireless end node of aspects 9-11, wherein the electrical assembly further includes a light emitting diode light, and
wherein the light emitting diode light is configured to blink a red color light to indicate the low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
13. The wireless end node of aspects 8-12, wherein the controller is configured to determine whether the wireless end node is decommissioned from the wireless communication system, and
wherein the controller is configured to set the wireless end node to operate in the long term storage mode when the controller determines that the wireless end node is decommissioned from the wireless communication system.
14. The wireless end node of aspect 13, wherein the controller is configured to determine whether the wireless end node is decommissioned from the wireless communication system every 24 hours.
15. A wireless communication system for a mobile environment comprising:
one or more wireless end nodes, each of the one or more wireless end nodes including:
a network coordinator connected to each of the one or more wireless end nodes.
16. The wireless communication system of aspect 15, wherein the electrical assembly of each of the one or more wireless end nodes further includes a memory storage,
wherein, when the wireless end node is operating in the long term storage mode and the sleep timer of the wireless end node counts down the long term storage time period, the controller is configured to power up, determine the power source level of the power source, and compare the power source level of the power source to an acceptable power source level threshold stored in the memory storage, and
wherein the wireless end node is configured to indicate a low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
17. The wireless communication system of aspects 15-16, wherein the long term storage time period is 24 hours.
18. The wireless communication system of aspects 16-17, wherein the acceptable power source level threshold is 2.9 volts for a 3.6 volt battery.
19. The wireless communication system of aspects 16-18, wherein the electrical assembly of each of the one or more wireless end nodes further includes a light emitting diode light, and
wherein the light emitting diode light of each of the one or more wireless end nodes is configured to blink a red color light to indicate the low level power source when the controller determines that the power source level of the power source is below the acceptable power source level threshold.
20. The wireless communication system of aspects 15-19, wherein the controller of each of the one or more wireless end nodes is configured to determine whether the wireless end node is decommissioned from the wireless communication system, and
wherein the controller of each of the one or more wireless end nodes is configured to set the wireless end node to operate in the long term storage mode when the controller determines that the wireless end node is decommissioned from the wireless communication system.
21. The wireless communication system of aspect 20, wherein the controller of each of the one or more wireless end nodes is configured to determine whether the wireless end node is decommissioned from the wireless communication system every 24 hours.
With regard to the foregoing description, it is to be understood that changes may be made in detail, especially in matters of the construction materials employed and the shape, size and arrangement of the parts without departing from the scope of the present invention. It is intended that the specification and depicted embodiment to be considered exemplary only, with a true scope and spirit of the invention being indicated by the broad meaning of the claims.
| Number | Date | Country | |
|---|---|---|---|
| 61613944 | Mar 2012 | US | |
| 61787691 | Mar 2013 | US | |
| 61613956 | Mar 2012 | US | |
| 61613949 | Mar 2012 | US | |
| 61613952 | Mar 2012 | US | |
| 61787719 | Mar 2013 | US | |
| 61613946 | Mar 2012 | US |
