Patent Description:
Typically, cold chain distribution systems are used to transport and distribute cargo, or more specifically perishable goods and environmentally sensitive goods (herein referred to as perishable goods) that may be susceptible to temperature, humidity, and other environmental factors. Perishable goods may include but are not limited to fruits, vegetables, grains, beans, nuts, eggs, dairy, seed, flowers, meat, poultry, fish, ice, and pharmaceuticals. Advantageously, cold chain distribution systems allow perishable goods to be effectively transported and distributed without damage or other undesirable effects.

Refrigerated trailers are commonly used to transport perishable goods in a cold chain distribution system. Often, refrigerated trailers include a refrigeration unit for the supply of cold air to a cargo space and together these are referred to as transportation refrigeration units, or TRUs. The refrigeration unit of such TRUs may comprise a compressor, a condenser with one or more associated condenser fans, an expansion device, and an evaporator with one or more associated evaporator fans, which are connected via appropriate refrigerant lines in a closed refrigerant flow circuit. The refrigeration unit may be mounted to the TRU trailer in operative association with a cargo space defined within the trailer for maintaining a controlled temperature environment within the cargo space. Air or an air/gas mixture is drawn from the interior volume of the cargo space by means of the evaporator fan(s) associated with the evaporator, passed through the airside of the evaporator in heat exchange relationship with refrigerant whereby the refrigerant absorbs heat from the air, thereby cooling the air. The cooled air is then supplied back to the cargo space.

On commercially available TRUs, the compressor, and typically other components of the transportation refrigeration unit, may be powered during transit by an on-board battery that is charged by a generator. In such systems, a prime mover of the system drives a generator that generates power. A known type of electrically driven TRU involves rigidly coupling a wheel axle of the TRU to a generator (of the rotational type) to generate electrical power. The generated power is stored in a battery and can be used to power an electric motor for driving the refrigerant compressor of the transportation refrigeration unit and also can be used for powering electric fan motors, for driving the condenser and evaporator motors, and for powering electric heaters associated with the evaporator. In addition, the battery can supply power to the other components of the TRU.

<CIT> discloses a kingpin for mounting to a semitrailer. The kingpin comprises a pin body detachably engageable with a towing vehicle-side semitrailer coupling and a sensor device disposed at the pin body and configured to detect a driving state of the semitrailer.

<CIT> discloses a magneto-elastically-based active force sensor, used with a tow coupling between a towed and a towing vehicle, which outputs a signal useful for determining forces acting on the coupling. The outputted force information may be provided by processor-enabled embedded software algorithms that take inputs from the force sensor and other sensors, may be used by one or more vehicle systems during operating of the vehicle, such as engine, braking, stability, safety, and informational systems. The force sensor includes directionally-sensitive magnetic field sensing elements inside the sensor, and shielding may be used around the sensors to reduce the influence of external magnetic fields on the sensing elements. The force sensor may be used with different tow coupling devices installed on different types of automobile cars and trucks.

<CIT> discloses a device for determining trailer force on the trailer of a truck trailer. The device comprises a base element, which is fastened on a frame of a trailer traction machine. A saddle plate is provided, which is fixed on the base element. The base element has a receiver opening, which is formed for receiving a kingpin of a semitrailer. Two <NUM>-component force measuring elements are provided, which are arranged between the saddle plate and the base element.

<CIT> discloses a towing load detection system for detecting whether a vehicle is towing an object. The system includes a controller and at least one proximity sensor operable to detect the presence of the object being towed. The controller is operable to cause a vehicle effect when the proximity sensor detects that the vehicle is towing an object.

It is desirable to improve the efficiency of TRUs equipped with such generators and batteries, by optimising the times and/or magnitudes at which the generator charges the battery.

The invention is defined by independent claims <NUM> and <NUM>, while preferred embodiments are defined in claims <NUM>-<NUM>, <NUM> and <NUM>.

Described herein is a kingpin for connecting a trailer to a tractor, the kingpin comprising: an integrated sensor arranged to measure a force applied to the kingpin, and a data connection arranged to transmit data of a force measured by the integrated sensor.

A kingpin, also referred to as a fifth-wheel coupling, is part of a trailer/TRU that provides the link between a tractor (via the fifth wheel of the tractor) and the trailer/TRU. By providing the kingpin with the integrated torque sensor it may be possible to determine whether, and optionally to what magnitude, a trailer connected to the kingpin is being pushed or pulled by a tractor connected to the kingpin. The sensor may measure a vector force (both direction and magnitude). This data may be obtained in real time and is valuable in deciding when to use the generator to generate power, thereby improving fuel efficiency. For example, if the trailer is being pushed, or decelerated, by the tractor then it is clear that the system as a whole is slowing down and so it would be beneficial to use the kinetic energy of the trailer to generate power via the generator. In contrast, if the trailer is being pulled, or accelerated, by the tractor then it is clear that the system as whole is accelerating and so it would be beneficial to not use the kinetic energy of the trailer to generate power as doing so would reduce the extent of acceleration. This is a simplified explanation of the value of the data from the kingpin sensor, and it will be appreciated that there are many other factors that may be considered when determining the optimal time and/or an optimal magnitude of power to generate with the generator. Other possible factors are discussed in more detail below.

In commercially available TRUs it is not presently possible to obtain data on the acceleration/deceleration of the trailer. Instead, International Standards ISO <NUM> and ISO <NUM> only provide for a CAN bus connection from the trailer to the truck that provides braking and suspension information of the trailer to the truck. These standards do not allow for any further data connections (e.g. a dedicated data connection relating to acceleration/deceleration). The present invention overcomes this problem by incorporating a torque sensor directly into the kingpin of a trailer to gather this data. As a result, no further data connections between the truck and trailer are required. The present invention is therefore suitable for use with the above mentioned International Standards.

The kingpin may comprise a plurality of integrated sensors. Each sensor may be arranged to measure to measure a force applied to the kingpin. Each sensor may be arranged to transmit data of a measured force via the data connection or each may have its own data connection for this purpose. This may provide a greater amount of data and/or more accurate data. Teachings below relating to specific of the sensor may apply to any/each of the plurality of sensors.

The sensor may be a torque sensor. This may allow a reaction force on the trailer (produced by the tractor) to be measured.

The sensor may extend partway through the kingpin in the vertical direction. The sensor may be configured to measure forces acting on the kingpin in the horizontal direction. In this way, the sensors may be arranged to measured forces in the same plane as push/pull forces on the trailer and a connected tractor.

The invention provides a trailer in the form of a transport engineless refrigeration unit as defined in claim <NUM>.

The kingpin may include any of the optional features described herein.

According to the invention, the control unit is configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on data of a force measured by the integrated sensor of the kingpin.

As mentioned above, this may optimise the efficiency of the TRU, by better control of the time/magnitude of generating power.

The trailer may comprise an accelerometer configured to measure acceleration of the trailer and/or a clinometer configured to measure an incline of the trailer. The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on a measured acceleration of the trailer and/or a measured incline of the trailer.

By also utilising acceleration and/or incline measurements, control of the generator can be further optimised. For example, if the trailer moves onto a downhill gradient but there is no push or pull force (i.e. it is moving at a steady speed), then it would be beneficial to generate power using the generator as it is likely to accelerate due to gravitational forces.

The trailer may comprise a speedometer configured the measure a speed of the trailer; and/or a brake sensor configured to detect a status of a brake of the trailer. The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on a measured speed of the trailer and/or a status of the brake of the trailer.

By utilising information on speed, more effective control of the generator may be achieved, as the power generated may be dependent on the speed at which the trailer is moving. By utilising information on the status of the brake, a driver's intention may be determined (e.g. they have pressed the brake sharply to decelerate quickly). This information may be useful in determining when/to what magnitude power may be generated, e.g. a desire for sharp declaration from a high speed may be optimal for power generation, as kinetic energy is used to power the generator rather than being wasted.

The trailer may comprise a weight sensor to measure the mass of trailer. The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on the mass of the trailer.

By utilising information on the mass of the trailer, a better approach to power generation may be taken as the mass of the trailer has a direct effect on the forces required to accelerate/decelerate and on kinetic energy.

The trailer may comprise a sensor configured to measure a state of charge of a battery. The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on a measured state of charge of the battery. The control unit may control the generator to generate power if the state of charge is below a predetermined threshold regardless of other measurements/data.

By utilising information on the state of charge of battery it may be easily determined whether a battery needs to be charged and by how much. For example, if the state of charge of a battery is very low the generator may generate power regardless of the other information acquired in order to ensure that the batter does not run out of charge. This is particularly important when a battery is used to cool a cargo space, as otherwise the cargo could be spoiled.

The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on power requirements of the transport engineless refrigeration unit. For example, if no power is required to chill a cargo space (e.g. the trailer is empty) then the generator may not charge the battery and/or the battery may not power the refrigeration unit.

According to another aspect the present invention provides a vehicle comprising a tractor and a trailer according to the the invention wherein the vehicle comprises: a data connection between the tractor and the trailer, and the tractor comprises: a speedometer configured the measure a speed of the tractor; and/or a brake sensor configured to detect a status of the brake of the tractor, wherein the speedometer and/or the brake sensor are connected to the control unit of the trailer via the data connection and the control unit is configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on a measured speed of the tractor and/or a status of the brake of the tractor.

The trailer may include any of the optional features described herein.

By utilising a data connection between the tractor and trailer, the speedometer and/or brake sensor of the tractor can supply data to be used in optimising the control of the generator.

The tractor may comprise a fuel consumption sensor configured to measure fuel consumption of the tractor and/or a pedal position sensor configured to measure a position of an accelerator pedal, brake pedal or clutch. The control unit may be configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on fuel consumption of the tractor and/or a pedal position.

The vehicle may comprise a telematics unit arranged to send measurements/data between the tractor and trailer and/or to a remote server. The telematics unit may be positioned in the TRU. In this way the data described herein may be stored for future use and optimisation processes. For example, control methods described herein may be altered based at least in part on measurements/data stored on a remote server.

The integrated sensor may be a torque sensor and the kingpin may include any of the optional features discussed in relation to the first aspect.

According to yet another aspect, the present invention provides a method of optimising control of a trailer connected to a tractor as defined in claim <NUM>.

By optimal it may be meant best in the interest of fuel efficiency, optionally taking into account other system requirements such as a state of charge of a battery and fuel level of a tractor.

The method is performed by the controller described above.

The determining of an optimal time for the generator to generate power and/or an optimal magnitude of power to generate may additionally be based on any one or a combination of: a measured acceleration of the trailer; a measured incline of the trailer; a measured speed of the trailer; a status of a brake of the trailer; a mass of the trailer; a measured state of charge of the battery; and power requirements of the transport engineless refrigeration unit.

The determining of an optimal time for the generator to generate power and/or an optimal magnitude of power to generate may additionally be based on any one or a combination of: a measured speed of the tractor; a status of the brake of the tractor; fuel consumption of the tractor; fuel level of the tractor; a position of an accelerator pedal, brake pedal or clutch of the tractor.

Certain preferred embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, in which:.

With reference to <FIG>, a commercially available vehicle system <NUM> is shown. The vehicle system <NUM> comprises a tractor <NUM> and a trailer <NUM> in the form of a transport refrigeration unit (TRU). The TRU <NUM> comprises a refrigeration unit <NUM> for the refrigeration of a cargo space (not shown). The TRU <NUM> also comprises a battery pack <NUM>, a generator <NUM> rigidly coupled to a wheel axle of the transport refrigeration system and arranged to charge the battery, an EBS (braking and suspension measurement) system <NUM>, and ABS (speed measurement) system <NUM>. The battery pack <NUM> comprises a controller configured to control the generator <NUM>, battery pack <NUM> and refrigeration unit <NUM> and receive measurements form the various measurement systems.

The vehicle system <NUM> also comprises a data connection <NUM> between the tractor <NUM> and trailer <NUM> in the form of a CAN bus. In use, data regarding braking and suspension of the trailer <NUM> is sent via this connection. However, the connection <NUM> is not equipped to handle any other data transfer between the tractor and trailer. In particular, there is no way for further cables or connectors to run between the tractor <NUM> and trailer <NUM> due to restrictions of International Standards.

In use the generator <NUM> generates power, and the controller prioritises supply of this power the TRU <NUM>. If the TRU <NUM> is off, or is not consuming all the generated power, the controller diverts the remaining power to charge the battery <NUM>.

With reference to <FIG>, there is shown a vehicle system <NUM> including a tractor <NUM> and a trailer in the form of a transport refrigeration unit (TRU) <NUM> having a kingpin <NUM> with an integrated sensor <NUM> arranged to measure a force applied to the kingpin <NUM>.

The TRU <NUM> comprises a refrigeration unit <NUM> for the refrigeration of a cargo space (not shown). The TRU <NUM> also comprises a battery pack <NUM> for powering the refrigeration unit <NUM>, a generator <NUM> rigidly coupled to a wheel axle of the transport refrigeration system and for charging the battery pack <NUM>, an EBS (braking and suspension measurement) system <NUM>, an accelerometer and clinometer system <NUM>, and an ABS (speed measurement) system <NUM>. The battery pack <NUM> comprises a sensor for measuring its state of charge (SOC) and a controller configured to control the generator <NUM>, battery pack <NUM> and refrigeration unit <NUM>.

The vehicle system <NUM> also comprises a data connection <NUM> between the tractor <NUM> and trailer <NUM> in the form of a CAN bus. In use, data regarding braking and suspension of the trailer <NUM> is sent via this connection.

In use, measurements of a force applied to the kingpin <NUM> are sent via a data connection <NUM> to the controller.

Based at least in part of the measurements of a force applied to the kingpin <NUM>, the controller controls when the generator <NUM> generates power to charge the battery pack <NUM>. For example, if the trailer <NUM> is being pushed, or decelerated, by the tractor <NUM> then it is clear that the system as a whole is slowing down and so it would be beneficial to use the kinetic energy of the trailer <NUM> to generate power via the generator <NUM>. In contrast, if the trailer <NUM> is being pulled, or accelerated, by the tractor <NUM> then it is clear that the system as whole is accelerating and so it would be beneficial to not use the kinetic energy of the trailer <NUM> to generate power as doing so would reduce the extent of acceleration. This is a simplified explanation of the value of the data from the kingpin sensor, and it will be appreciated that there are many other factors that may be considered when determining the optimal time and/or an optimal magnitude of power to generate with the generator <NUM>. This control and some further factors are described in more detail below, with reference to <FIG>.

With reference to <FIG>, the kingpin <NUM> is shown in more detail. Here, it can be seen that the kingpin <NUM> comprises an integrated torque sensor <NUM>. The torque sensor <NUM> extends partway through the kingpin <NUM> in the vertical direction and is configured to measure forces acting in the horizontal plane (labelled X). The kingpin <NUM> is part of the trailer <NUM>, and connects to the fifth wheel <NUM> of the tractor <NUM> in a conventional way to connect the two. It will be appreciated that additional sensors could be incorporated into the kingpin <NUM>.

<FIG> shows the state of the kingpin <NUM> when the tractor is pulling the trailer, and accelerating it. The force <NUM> will be measured by the integrated sensor <NUM> and transmitted to the controller previously discussed.

<FIG> shows the state of the kingpin <NUM> when the tractor is pushing, or decelerating the trailer, it is clear that the horizontal force <NUM> being measured would then be in the opposite direction.

As previously mentioned, there are many other factors that could also be taken into account by the controller when determining when and/or to what extent the generator <NUM> should generate power. With reference to <FIG> a number of other considerations are described. In each of these the controller receives data from sensors including the integrated sensor <NUM> of the kingpin <NUM> indicating a force, a speedometer indicating vehicle speed, accelerometer indicating vehicle acceleration, clinometer indicating incline and brake sensor indicating a state of the brake on the trailer. These various indications are shown in columns <NUM> to <NUM>. In addition, the controller receives data regarding a state of charge of the battery pack <NUM>. From the data provided by these sensors it is possible to deduce (amongst other things) three pieces of information: the fuel consumption of the tractor <NUM>; the change in momentum of the trailer <NUM> and the incline of the road. These are shown in columns <NUM> to <NUM>.

Combining all of this data, the controller is configured to make decision on whether to use the generator <NUM> to generate power and to what extent power should be generated. For example, in row <NUM>, it can be seen that it has been deduced that the vehicle <NUM> is braking on a downhill slope, so it would be beneficial to generate maximum power with the generator <NUM> in order to recover some of the kinetic energy of the trailer <NUM> to charge the battery <NUM> rather than it simply being wasted. In contrast, in row <NUM> it can be seen that the vehicle <NUM> is accelerating on an uphill incline and so the fuel consumption of the tractor <NUM> is very high. In this instance, the controller does not generate power with the generator (unless the state of charge of the battery is dangerously low) as doing so wold increase fuel consumption even more, and reduce acceleration.

Claim 1:
A trailer (<NUM>) in the form of a transport engineless refrigeration unit, the trailer comprising:
a kingpin (<NUM>) comprising an integrated sensor (<NUM>) arranged to measure a force applied to the kingpin, and a data connection (<NUM>) arranged to transmit data of a force measured by the integrated sensor,
a control unit arranged to receive the data of a force measured by the integrated sensor,
a refrigeration unit (<NUM>),
a battery (<NUM>) arranged to power the refrigeration unit, the control unit and/or the integrated sensor of the kingpin; and
a generator (<NUM>) arranged to generate power from an axle of the trailer to charge the battery,
wherein the control unit is configured to control when the generator generates power and/or to what magnitude the generator generates power based at least in part on data of a force (<NUM>) measured by the integrated sensor of the kingpin.