Control System Design and Optimization Using LabVIEW for a Plug in Hybrid Electric Vehicle as Part of EcoCar: The NeXt Competition

Abstract

Embry Riddle Aeronautical University is part of EcoCar: The NeXt Challenge, an advanced vehicle competition run by Argonne National Labs and sponsored by General Motors and the Department of Energy. The competition tasks 16 schools around the country with designing and implementing the most efficient vehicle architecture. As part of the EcoCar Challenge, Embry Riddle Aeronautical University is working on developing a controls strategy for a Plug in Hybrid Electric Vehicle. The control system is designed to optimize efficiency and consumer acceptability by allowing the EcoEagles to control each of the cars sub-systems. Control is done using CAN bus communication that utilizes National Instruments (NI) single board reconfigurable input / output (sbRIO) real time hardware. The EcoEagles powertrain architecture includes GM’s two-mode hybrid electric transmission which contains two 55kW electric motors, a 1.3 liter turbo diesel engine running on B20 biodiesel, and a 12.8 kWh lithium-ion battery pack produced by A123 Systems. Each component has a control module that interfaces directly with the subsystems and hardware on the vehicle. These controllers are: the Traction Power Inverter Module (TPIM), the Engine Control Module (ECM), and the Battery Pack Control Module (BPCM). Vehicle control and communication between these modules is managed by the EcoEagles, two controllers called the Supervisory Control Unit (SCU) and the Gateway (GW). The purpose of the gateway is to control the flow of CAN communication between modules and to isolate the ECM and BPCM from the vehicle to avoid data interference. Communication is done on two separate CAN buses, the Power Train Expansion Bus (PTEB), and the High Speed Bus (HS). The controls diagram can be seen in Figure 1. The paper will go into detail on shift strategy and engine operation where optimization was used to maintain efficient operation of the engine. The paper will also describe the control strategy that was developed using coupled LabVIEW Statecharts [1] with CAN messaging inputs from all of the control modules in order to maintain safe efficient operation.