UNIQUE TANK GEOMETRY

FIELD

The embodiments disclosed herein relate generally to a device and method for measuring a fuel level in a fuel tank of a transport refrigeration system ("TRS").

BACKGROUND

An electrical/mechanical fuel level sensor device can have a mechanical assembly connected to a potentiometer. The mechanical assembly typically has mechanical gears connected to an arm with a floater. The arm and the floater are disposed inside a fuel tank. A simple fuel level display, that is basically a dial with a needle, can be connected to the mechanical gears so that the needle moves based on the position of the floater. The metal gears can be connected to the potentiometer, such that when the metal gears move, the potentiometer's divided resistances change accordingly. The potentiometer is connected to a remote power source. Generally, the remote power source is a generator set ("genset") of a TRS and electricity is delivered through the potentiometer via an electrical wire. Accordingly, the potentiometer is powered only when the TRS is on and/or is set to provide electricity to the potentiometer. Based on the position of the arm of the mechanical assembly, the mechanical gear can move a sliding contact of the potentiometer to affect its electric potential. Accordingly, the movement of the mechanical gears due to the position of the arm displaced by the floater being floated by the fuel in the fuel tank, can change the electric potential at the potentiometer, which can be detected via the same electrical wire. The measurement of electric potential which may be an approximation of a fuel level in the fuel tank can be sent via measurement signal to a TRS controller of the TRS

The electrical/mechanical fuel level sensor device's accuracy is dependent on the mechanical design and properties of one or more of the fuel tank, mechanical gears, the arm, the floater, and the condition of the wire(s) and any wire connectors that connects the potentiometer to the vehicle's components. Accordingly, the electrical/mechanical fuel level sensor device is not accurate. In particular, the electrical/mechanical fuel level sensor device is not accurate when there is movement of the fuel in the fuel tank (e.g. movement of the transport, vibration from the engine, etc.) and/or when the fuel tank is not in a perfectly leveled position horizontally. That is, the fuel level displayed on the remote display would be inaccurate when the transport temperature controlled trailer unit is going up an incline or going down a decline, because the floater position would move up or down based on the incline or decline angle (i.e. position of the fuel in the fuel tank), and not necessarily an amount of the fuel contained in the fuel tank. There are also many other factors and conditions that prevent the electrical/mechanical fuel level sensor device from an accurate measurement of the fuel level in the fuel tank.

SUMMARY

The embodiments described herein are directed to a fuel level measurement system and a fuel level measurement device for a fuel tank of a transport refrigeration system. The

embodiments described herein include a fuel level measurement system without having a wired connection between the fuel level measurement device and a remote controller that displays the fuel level.

The embodiments described herein are directed to fuel level sensing on a variety of tank configurations (e.g. size, diameter, etc.) utilizing a single sensor hardware design and an algorithm to compensate for tank size, shape, ambient temperature, motion, and rapid volume change events.

An embodiment of a method for adjusting an operation of a fuel level sensor includes a processor receiving a selection of a fuel tank type and storing the fuel tank type to a computer readable memory; and applying a strapping table related to the fuel tank type to a fuel level data received by the processor to generate an adjusted fuel level. The method can also include storing the adjusted fuel level to the memory.

In one embodiment, a fuel measurement system and a wireless fuel level measurement device for a TRS are provided. An embodiment of the wireless fuel level measurement device includes a memory which stores computer-readable instructions for calculating a fuel level, and for adjusting operation of a fuel level sensor based on tank configuration data.

The wireless network interface in communication with the processor for communicating the fuel level to a remote controller, such as a TRS controller. The battery powers the processor, the memory, the temperature sensor, and the wireless network interface. Thus, the wireless fuel level measurement device can be powered independently from the transport's engine and/or power supply. Accordingly, the wireless fuel level measurement device does not require an electrical wire from the transport's engine to power the wireless fuel level measurement device. The embodiments described herein are also directed to adjusting how the battery powered wireless device, such as a fuel level sensor, is operating based on a detected ambient temperature and condition of the battery that powers the fuel level sensor.

An embodiment of the wireless fuel level measurement device includes a sealed casing that encases the processor, the memory, the temperature sensor, the wireless network interface, and the battery. The sealed casing can include a housing and a potting material, wherein the processor, the memory, the temperature sensor, the wireless network interface, and the battery are disposed in the housing, and the potting material seals the housing to encase the processor, the memory, the temperature sensor, the wireless network interface, and the battery inside the sealed casing.

In an embodiment, the wireless fuel level measurement device includes a potentiometer connected to the processor for communicating raw fuel level data. The potentiometer can be contained in a compartment that is separated from a compartment of the housing containing the processor, the memory, the temperature sensor, wireless network interface, and the battery.

The potentiometer can be connected to a floater assembly, which includes a floater configured to be floated by a fuel in a fuel tank, and an arm connected to the floater, wherein the arm is displaced when the floater is moved, and the raw fuel level data is determined by a position of the floater.

An embodiment of a fuel level measurement system includes a remote controller that displays the fuel level communicated from the wireless network interface of the wireless fuel level measurement device. The remote controller can also send data to the wireless fuel level measurement device.

An embodiment of a method for producing a sealed wireless fuel level measurement device includes providing a housing; placing logic board inside the housing, wherein the logic board includes a memory, a processor, the temperature sensor, and a wireless network interface; and completely sealing the logic board that is inside the housing by covering an opening of the housing with a layer of a potting material.

The logic board may include a battery for powering the logic board inside the housing. Alternatively, the method can include a step of placing the battery that powers the logic board inside the housing, prior to the step of completely sealing the logic board.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers represent corresponding parts throughout.

FIG. 1 A illustrates a side view of an embodiment of a transport temperature controlled trailer unit with a transport refrigeration system.

FIG. IB illustrates a side view of an embodiment of a trailer unit with a fuel level measurement device system and a cutaway side view of a fuel tank.

FIG. 2 illustrates a cutaway side view of an embodiment of a fuel level measurement device.

FIG. 3 illustrates a front perspective view of an embodiment of a fuel level sensor for a fuel tank of a transport refrigeration system.

FIG. 4 illustrates a rear view of an embodiment of a fuel level sensor for a fuel tank of a transport refrigeration system.

FIG. 5 illustrates a block diagram of an embodiment of the logic board.

FIG. 6 illustrates a flowchart of an embodiment of a method for adjusting an operation of a fuel level sensor. DETAILED DESCRIPTION

The embodiments described herein are directed to a transport fuel level measurement device and 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 "transport refrigeration system" refers to a refrigeration system for controlling the refrigeration of an in internal space of the reefer. The term "wireless" refers to a communication system that is configured to transmit data via a wireless connection over a short distance, such as, for example, between different points of a reefer that is in transport. The term "remote controller" refers to an electronic device that is configured to wirelessly communicate with another wireless device to receive data, manage, command, direct and/or regulate the behavior of the wireless device. An example of the remote controller is a TRS control unit. The term "TRS control unit" refers to an electronic device that is configured to manage, command, direct and regulate the behavior of one or more TRS refrigeration components (e.g., an evaporator, a blower, a heat exchanger, etc.), a TRS engine, a TRS main battery, a TRS alternate battery (if included in the transport refrigeration system), a TRS fuel tank, etc.

FIG. 1A illustrates a side view of a temperature controlled transport unit 100 with a TRS 50. The TRS 50 includes a transport refrigeration unit (TRU) 101, a genset (not shown), and a plurality of wireless sensors including a door sensor 113 and a fuel level sensor 114. The TRU 101 is installed on a side wall of the transport unit 100. In some embodiments, the generator set of the TRS 50 can be mounted under the transport unit 100. The TRS 50 is configured to transfer heat between an internal space 30 of the transport unit 100 and the outside environment. In some embodiments, the TRS 50 is a multizone system in which different zones or areas of the internal space 30 are controlled to meet different refrigeration requirements based on the cargo stored in the particular zone. The TRS 50 also includes a wireless communication system 10 and a fuel tank 110. The wireless communication system 10 includes a network coordinator (not shown), an antenna 20, and a plurality of wireless sensors (e.g., the door sensor 113 and the fuel level sensor 114). The wireless communication system 10 is configured to communicate information regarding the TRS 50 to a remote controller, such as a TRS controller (not shown) of the TRS 50. In some embodiments, the TRS controller can be housed in the TRU 101.

FIG. IB illustrates a side view of an embodiment of a transport temperature controlled trailer unit 100 with a fuel level measurement system 102. The transport temperature controlled trailer unit 100 may be for delivering a reefer with a transport refrigeration system. The fuel level measurement system 102 includes a remote controller 104 (e.g. a TRS controller) that is in wireless communication 106 with a wireless fuel level measurement device 108. The wireless fuel level measurement device 108 is connected to a fuel tank 110 of the transport temperature controlled trailer unit 100. FIG. IB illustrates a cutaway side view of the fuel tank 110 to show the configuration of the fuel level measurement device 108 that is connected to the fuel tank 110. The fuel level measurement device 108 has a floater assembly 1 12 disposed inside the fuel tank 110, and a fuel level sensor 114 disposed outside the fuel tank 110.

FIG. 2 shows a cutaway side view of an embodiment of the fuel level measurement device 108 shown in Fig. IB. The fuel level measurement device 108 includes the floater assembly 112 and the fuel level sensor 114. The floater assembly 112 includes a floater 116 configured to float on fuel housed inside the fuel tank 110 (shown in Fig. IB). The floater 116 is connected to an arm 118, which is connected to mechanical gears 120. The floater 116 and the arm 118 are configured to be disposed inside the fuel tank.

The fuel level sensor 114 includes a potentiometer 122 that connects to the mechanical gears 120. For example, the potentiometer 122 can include one or more magnets 124 that match with one or more magnets 126 of the mechanical gears 120. The fuel level sensor 114 includes a casing 128.

The casing 128 has a housing 130 and a layer of potting material 132. The housing 130 can be made from, for example, an epoxy encapsulant which cures at room temperature to a tough, semi-rigid polymer, which has very good resistance to water, acids and bases and organic solvents.

The housing 130 has a first compartment 134 for containing the potentiometer 122, and a second compartment 136 for containing a logic board 138.

The first compartment 134 has a shaped wall portion 140 configured to mate with the floater assembly 112. For example, the first compartment 134 can include interface fitting structure (e.g. crush ribs) configured to fit tightly with the floater assembly 112.The shaped wall portion 140 is between the first compartment 134 and the second compartment 136. The shaped wall portion 140 may have one or more grooves 142 for wire(s) 144 to travel across between the first compartment 134 and the second compartment 136. The one or more grooves 142 can provide positioning of the wire(s) 144 so as to protect the wire(s) 144 from the environment (e.g. rain, snow, mud, dirt, rocks, etc.) when the fuel level sensor 114 is installed to the fuel tank 110. In an embodiment, the wire(s) 144 are integrally connected to the potentiometer 122 and the logic board 138, without any wire "connectors" (which generally have plastic clips and/or thin metal connectors) that can rust or wear out during normal use over time.

The housing's 130 second compartment 136 is configured to receive and contain the logic board 138. The second compartment 136 is separated from the first compartment 134, such that the second compartment 136 can contain the logic board 138 and be sealed completely and separately from the first compartment 134. The sealing of the second compartment 136 can be performed by providing the layer of potting material 132 over the logic board 138. The result provides a completely sealed logic board 138 contained in a sealed compartment 136 of the casing 128 that protects the logic board 138 from the elements.

FIG. 5 illustrates a block diagram of an embodiment of the logic board 138 for the fuel level sensor 114. The logic board 138 can include (or be connected to) one more or more of a processor 200, a memory 201, a network interface 202, a battery 203, and a temperature sensor 204. In another embodiment, the second compartment 136 contains one more or more of the processor 200, the memory 201, the network interface 202, the battery 203, and the temperature sensor 204. The memory 201 stores computer-readable instructions for the operation of the fuel level sensor to compensate for different fuel tank configurations (e.g. size), so that a single design of the fuel level sensor can report a fuel level of a fuel tank, without the fuel tank configuration affecting the reported fuel level. Further, the memory 201 can store data for one or more strapping tables for one or more fuel tank types.

FIG. 6 illustrates a flowchart of an embodiment of a method 300 for adjusting an operation of a fuel level sensor. The method 300 adjusts the operation of the fuel level sensor to compensate for different fuel tank configurations (e.g. size), so that a single design of the fuel level sensor can report a fuel level of a fuel tank, without the fuel tank configuration affecting the reported fuel level.

There are multiple tank geometries used in the commercial transportation industry. In order to significantly improve the accuracy of a fuel level sensor, a system needs to be

configured with a strapping table (also known as fuel tank strapping chart) that is unique to the tank used in the application.

The method 300 allows for the fuel level sensor to be configured for the application- specific tank geometry. A fuel tank type can be selected 302 by a user at installation of the fuel level sensor. At installation of the fuel level sensor to a fuel tank, the fuel level sensor is configured either by sending a calibration data via a download to the fuel level sensor end node using a sensor network or by locally selecting the calibrations when they are pre-loaded and indexed on the sensor end node. Thus, the fuel tank type is stored into a memory 201 (shown in FIG. 5) of the fuel level sensor. Then the processor, following the computer-readable instructions, applies 304 a strapping table associated with the fuel tank type selected. The same fuel level sensor can be reconfigured for different tank geometries. The fuel level sensor uses the calibration programmed into the memory 201 (shown in FIG. 5), to map the input to the fuel level sensor to a known percentage capacity of the fuel tank. This design improves upon existing transport fuel level sensors in the market by accommodating more than one tank style and can accommodate cylindrical tanks of different diameters along with rectangular and irregularly shaped tanks. It provides a means to dynamically replace the calibration in the sensor with a new one. Further, this device and method improves upon the current analog resistive fuel float system by applying a calibration to the resistive element output prior to sending the reading to the rest of the system. A simple fuel level display 146, that is basically a dial with a needle, can be provided at the potentiometer 122 so that the needle moves based on the position of the floater 116.

The floater 116 is floated by a fuel contained in the fuel tank. The floater 116 is connected to the arm 118 of the floater assembly 112, and the displacement of the floater 116 due to the level of the fuel rotates the arm 118 about a pivot 148 at a gear mechanism 120 of the floater assembly 112. The gear mechanism 120 is connected to the potentiometer 122 of the fuel level sensor 114, by for example, a magnetic connection so that the fuel level sensor 114 can be quickly and easily be connected and disconnected from the floater assembly 112.

FIG. 3 shows an embodiment of a front side of an embodiment of a fuel level sensor 114 of a fuel level measurement device 108. The front side of the fuel level sensor 114 would face away from a fuel tank when the fuel level sensor 114 is connected to the fuel tank. The fuel level sensor 114 has a substantially cylindrical shape in general. The analog display 146 having a needle dial 150 is disposed at (or substantially near) the center of the fuel level sensor 114. A beveled view angle portion 152 is angled from a first surface portion 154 of the housing 130 of the fuel level sensor 114 towards the analog display 146. The beveled view angle portion 152 can enhance the visibility of the analog display 146.

In some embodiments, a light-emitting diode (LED) 156 is provided to be visible on the surface portion 154. The LED 156 can be connected to the processor on the logic board 138 for displaying an information regarding an operation and/or condition of the fuel level sensor 114. The housing 130 can include a recess for the LED 156 for enhancing viewability of the LED 156 when lit.

FIG. 4 shows and embodiment of a backside (view from the rear) of an embodiment of a fuel level sensor 114. The backside would face towards the fuel tank when the fuel level sensor 114 is connected to the fuel tank. The embodiment of the fuel level sensor 114 shows a first compartment 134 and a second compartment 136 separated by a wall portion 140, wherein the first compartment 134 is disposed near the center of a substantially cylindrically shaped housing 130, with the second compartment 136 forming a ring-shaped compartment which surrounds the first compartment 134. Accordingly, the logic board contained in the second chamber 136 can be substantially ring-shaped to match the shape of the second compartment 136.

The wall portion 140 is configured to receive a gear mechanism of a floater assembly. For example, the wall portion 140 can include an interface fitting structure 141 (e.g. crush ribs) configured to fit tightly with most conventional types of floater assembly. The first compartment 134 contains a potentiometer 122, which has wire(s) 144 extending from it. The wire(s) 144 navigate through the wall portion 140 via matching groove(s) towards a logic board contained in the second compartment 136. The second compartment 136 is completely sealed with a layer of potting material 132.

In an embodiment, a fuel level sensor 114 can be added to an existing resistive fuel gauge and mechanical fuel float assembly, such that the combination provides the resistive fuel gauge to be embedded into a sealed casing with the fuel level measurement device digital component in order to provide a rugged fuel measurement device.

The embodiments of the fuel level measurement device 108 described herein can provide one or more of the following features: Communication of fuel level in a fuel tank to a remote controller is performed wirelessly (wires can degrade over time); also no external wire connectors are needed (like wires, external connectors that connect various electrical components can wear out, be damages, rust, oxidize, etc.); and electronics of the fuel level sensor are completely sealed and protected from the elements. Advantages of the above embodiments include, but are not limited to, an improvement in reliability of fuel level sensing technology for reefers due to elimination of exposed wires that are subject to damage during transport of the reefer; improvement in the serviceability of the fuel level sensing technology, because wired fuel sensor systems are time consuming to troubleshoot and can be costly to repair, while embodiments of the wireless fuel level measurement device can provide fast and easy installation and/or replacement of the fuel level measurement device to the fuel tank of the transport; and viewability of an analog display. For wired fuel sensor systems, wherein wires provide power to the electronic fuel level measurement devices and/or the wires are conduits of data from the fuel level measurement device to a TRS controller, the wires have been found to be subject to normal wear and tear which disables the fuel sensor system. When damaged, these systems and the wires can be time consuming to repair when there is a case of failure. A wireless fuel level measurement device and system has no exposed wires that can be damaged by normal wear and tear. Further, the wireless fuel level measurement device can be easily and quickly replaced, if there is a case of failure.

Aspects:

It is noted that any of the aspects 1-4 and/or features therein can be combined with any of the aspects 5-11 and any of the aspects 12-18 and/or features therein. Any of the aspects 5-11 and/or features therein can be combined with any of the aspects 12-18 and/or features therein. 1. A method for adjusting an operation of a fuel level sensor, comprising:

a processor receiving a selection of a fuel tank type; and

the processor applying a strapping table related to the fuel tank type selected to a fuel level data received by the processor. 2. The method according to aspect 1, further comprising the processor receiving the fuel level data.

3. The method according to any of the aspects 1-2, further comprising the processor generating an adjusted fuel level based on the processor applying the strapping table to the fuel level data.

4. The method according to any of the aspects 1-3, wherein the processor applying the strapping table to the fuel tank type selected to the fuel data received by the processor includes mapping an input to the fuel level sensor to a known percentage capacity of the fuel tank.

5. A wireless fuel level measurement device, comprising:

a memory, which stores computer-readable instructions for:

calculating a fuel level, and

adjusting operation of a fuel level sensor based on fuel tank type data;

a processor in communication with the memory, which executes the computer-readable instructions;

a wireless network interface in communication with the processor for communicating the fuel level to a remote controller; and

a battery that powers the processor, the memory, and the wireless network interface. 6. The wireless fuel level measurement device according to any of the aspects 5, wherein the adjusting operation includes applying a strapping table related to the fuel tank type selected to a fuel level data received by the processor.

7. The wireless fuel level measurement device according to any of the aspects 5-6, wherein the adjusting operation includes mapping an input to the fuel level sensor to a known percentage capacity of the fuel tank.

8. The wireless fuel level measurement device according to any of the aspects 5-7, further comprising:

a sealed casing that encases the processor, the memory, the wireless network interface, and the battery.

9. The wireless fuel level measurement device according to any of the aspects 5-8, wherein the sealed casing includes:

a housing, and a potting material, wherein the processor, the memory, the wireless network interface, and the battery are disposed in the housing, and the potting material seals the housing to encase the processor, the memory, the wireless network interface, and the battery inside the sealed casing.

10. The wireless fuel level measurement device according to any of the aspects 5-9, further comprising a potentiometer connected to the processor for communicating raw fuel level data. 11. A fuel level measurement system, comprising:

the wireless fuel level measurement device according to aspect 10; and

the floater assembly connected to the potentiometer, the floater assembly including: the floater configured to be floated by a fuel in a fuel tank; and

an arm connected to the floater, wherein the arm is displaced when the floater is moved, and the raw fuel level data is determined by a position of the floater.

12. A method for adjusting an operation of a fuel level sensor, comprising:

a processor receiving a selection of a fuel tank type;

storing the fuel tank type to a computer readable memory that is in communication with the processor; and

the processor applying a strapping table related to the fuel tank type to a fuel level data received by the processor to generate an adjusted fuel level.

13. The method according to aspect 12, further comprising storing the adjusted fuel level to the memory.

14. The method according to any of the aspects 12-13, further comprising replacing a fuel tank calibration data with another fuel tank calibration data to the memory.

15. The method according to aspect 14, further comprising installing the fuel level sensor to the fuel tank of the fuel tank type. 16. The method according to any of the aspects 12-15, further comprising installing the fuel level sensor to the fuel tank of the fuel tank type.

17. The method according to any of the aspects 12-15, further comprising downloading the another fuel tank calibration data from a network.

18. The method according to any of the aspects 12-15, wherein the processor applying the strapping table to the fuel tank type selected to the fuel data received by the processor includes mapping an input to the fuel level sensor to a known percentage capacity of the fuel tank.

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.