Drive Independent e-Trailer using Smart King-pin

In the road transportation sector, CO2 emission target is set to reduce by at least 45% by 2030 as per the European Green Deal. Heavy Duty Vehicles contribute almost quarter of greenhouse gas emissions from road transport in Europe and drive majorly on fossil fuels. New emission restrictions creates a need for transition towards reduced emission targets. Also, increasing number of emission free zones within Europe, give rise to the need of hybridization within the truck and trailer community.
Currently, in majority of the cases the trailer units do not possess any kind of drivetrain to support the truck. Trailers carry high loads, such that while accelerating, high power is needed. On the other hand, while braking the kinetic energy is lost, which otherwise could be recaptured. Thus, having a trailer with electric powertrain can support the truck during traction and can charge the battery during braking, helping in reducing the emissions and fuel consumption. Using the King-pin, the amount of support required by trailer can be determined, making it an independent trailer, thus requiring no modification on the truck.
Given the heavy-duty environment in which the King-pin operates, the measurement design around it should be robust, compact and measure forces within certain accuracy level. Moreover, modification done to the King-pin is not apricated. These are also the challenges faced by V-Tron, a leading company in the field of services in mobility domain.
The goal of this project is to design a smart King-pin, which is robust, compact and provides force component measurement within certain accuracy, to the independent e-trailer, without taking input from truck, and investigate the energy management system of the independent e-trailer to explore the charging options. As a result, this can help reduce the emissions and fuel consumption.

Eindrapportage

Proposed force measurement system mounted on the kingpin works on the concept of deformation. It is designed to ensure robustness, compactness, force measurement within certain accuracy range and no modification on the king-pin. It is simulated in CAD to determine the specifications and material of the measurement system. A magneto-inductive sensor is selected to measure the deformation which acts as an input signal to the e-trailer driveline.

A Simulink model of truck-trailer combination based on the resistance force in longitudinal direction is developed. A PI controller is developed based on the sensor mapping and the driver feel. The controller receives force signal input from the kingpin measurement system. As response to the controller signal the electric power-train of the e-trailer supports the truck during traction and charges the battery during braking, helping in reducing the energy consumption. It is ensured the e-trailer only compensates for its own resistance forces, thus never pushes the truck. Moreover, the trailer driveline require signals from the mounted force measurement system, and not the truck, making it independent of the truck unit.

The proof of concept is validated on the MORE vehicle parameters which is comparable to a car scaled vehicle. The tests are performed at low speeds up to 20kmph, on single axle e-trailer weighing 600kgs and truck mass of 2000kgs. The results show clear distinction between traction and braking, and the e-trailer able to follow a force set-point input. It is found that the force measurement system is capable of measuring force up to 26N or mass of approximately 2.6kgs, which is quite accurate for the given application.

Further, minor refinements could be done to reduce the effect of noise by galvanizing measurement sensor and fine tuning controller parameters for braking. Outcome of this project will be carried forward in other extended projects.