E-trailer

This page provides the steps on how to model e-trailer project from e-Traction. e-trailer project is a concept project from e-Traction in which e-trailer is a normal trailer that has an electric motor mounted to one of its axle.
The ultimate goal of this project is to increase energy efficiency [kWh/km] hence reducing operating cost.

Creating the simulation

All of the component modules used in this simulations can be downloaded from (insert e-trailer folder)
The first step in creating this simulation is the same as the example simulation for Parallel Hybrid vehicle simulation. Click here to learn more.

Test scenarios

The test scenarios that will be used for this simulation is the so-called WHVC (World Harmonized Vehicle Cycle).
To get the same result as the simulation result presented below, do not change any global surrounding environment variable inside the parameter_main file.

ECU

A simple control algorithm has been developed and implemented into the e - trailer model in order to control the energy distribution between the Internal Combustion Engine and the Electric Machine. The control algorithm used the accelerator and brake pedal position to determine the demanded torque by the vehicle so that it can follow the desired driving cycle. The amount of throttle and brake required was calculated by the driver model which also includes the gear shift logic that calculates the required gear number for a certain moment. The electric machine is used together with the I.C.E. to achieve the demanded torque when the ECU determined that the demanded torque is above the maximum capability of what the engine can supply. If the state of charge of the battery is lower than the minimum charge value, the electric machine will be used as a generator to charge the battery. The electric machine is also used for braking the vehicle when possible, however, mechanical brakes will be used when the braking from the electric machine is not sufficient.

Plant model

The plant model for e-trailer project is split up into two group, those are the truck and the trailer.

e-trailer plant model.

The vehicle topology for e-trailer is similar to the Parallel Hybrid vehicle example. However, the electric motor in e-trailer is connected to the trailer wheel while the Parallel Hybrid vehicle connect the electric motor to the mechanical gear which connects both engine and electric motor together.

The input signals for truck component modules are:

Module	Input signal	Signal label	Retrieved from
Internal combustion engine	Requested engine speed	Eng_nReq_radps	ECU cmd
	Switch Speed / torque control	Eng_flgReqSwitch_B
	Requested engine torque	Eng_tqReq_Nm
	Exhaust brake ON / OFF	Eng_flgExhaustBrake_B
	Engine ON / OFF	Eng_flgonoff_B
	Starter motor ON / OFF	Eng_strtReq_B
	Fuel cut off	Eng_flgFuelCut_B
	Engine rotational speed	phys_speed_radps	Clutch mechanical fb output
Clutch	Requested clutch pedal position	Clu_ratReq_B	ECU cmd
	Clutch torque input	phys_torque_Nm	ICE mechanical output
	Clutch inertia input	phys_inertia_kgm2
	Clutch rotational speed input	phys_speed_radps	Transmission mechanical fb output
Transmission	Requested gear number	Transm_nrGearReq	ECU cmd
	Transmission torque input	phys_torque_Nm	Clutch mechanical output
	Transmission inertia input	phys_inertia_kgm2
	Transmission rotational speed input	phys_speed_radps	Final gear mechanical fb output
Final gear	Final gear torque input	phys_torque_Nm	Transmission mechanical output
	Final gear inertia input	phys_inertia_kgm2
	Final gear rotational speed input	phys_speed_radps	Chassis mechanical fb output
Truck Chassis	Requested chassis brake torque	Chassis_tqBrake_Nm	ECU cmd
	Chassis torque input	phys_torque_Nm	Plant model total vehicle torque
	Chassis inertia input	phys_inertia_kgm2	Plant model total vehicle inertia
	Drivecycle slope	Chassis_slopeRoad_Rad	Test scenarios

The input signals for trailer component modules are:

Module	Input signal	Signal label	Retrieved from
Battery	Battery current input	battery	Plant model battery current input
	Battery Actual cooling flow	Batt_flowActCooling_kgps	ECU cmd
Electric machine	Requested electric machine speed	ElecMac_nReq_radps	ECU cmd
	Switch speed / torque control	ElecMac_flgReqSwitch_B
	Requested electric machine torque	ElecMac_tqReq_Nm
	Electric machine actual cooling flow	ElecMac_flowActCooling_kgps
	Electric machine voltage input	phys_voltage_V	Battery electrical output
	Electric machine rotational speed input	phys_speed_radps	Trailer chassis sensor
Electrical auxiliary system	Requested power	Aux_pwrElecReq_W	ECU cmd
	Voltage input	phys_voltage_V	Battery electrical output	Truck Chassis	Requested chassis brake torque	Chassis_tqBrake_Nm	ECU cmd
Chassis torque input	phys_torque_Nm	Plant model total vehicle torque
Chassis inertia input	phys_inertia_kgm2	Plant model total vehicle inertia
Drivecycle slope	Chassis_slopeRoad_Rad	Test scenarios