Michael P.C. Cornwall - Wineman Technology, Inc.
Todd VanGilder - Wineman Technology, Inc.
Darryn La Zar - Wineman Technology, Inc.
Todd VanCamp - Ford Motor Company
Fuel cells are electrochemical devices that convert hydrogen gas and atmospheric oxygen into electrical energy and water. Ford Motor Company is pursuing fuel cells as an alternative energy source for powering passenger vehicles. Fuel cell research requires a test system to
- Simulate vehicle inputs to the fuel cell
- Control and monitor the fuel cell and the system around it
- Acquire analysis data
- Adapt easily to future fuel cell prototypes
Fuel cells require precise incoming-resource control, as well as tightly balanced temperature, flow, and coolant pressure control. The engine control unit (ECU) electronically controls fuel cells to respond to driver input. The ECU provides closed-loop control via incoming and outgoing controller area network (CAN) bus signals. After developing new fuel cell prototypes, the Ford Fuel Cell Development Team needs to be able to quickly adjust the test stand configuration to adapt to the new fuel cell.
Building a Complete Hardware and Software Solution
Ford Motor Company selected NI Gold Alliance Parter Wineman Technology to develop a software solution that provides the underlying control, data acquisition, and monitoring system architecture. We chose NI VeriStand and the INERTIA real-time control add-on for development and deployment because they provided an easy-to-use test software environment. For hardware, we chose NI PXI, SCXI, NI reconfigurable I/O (RIO) field-programmable gate array (FPGA) modules, and an EtherCAT distributed I/O device to provide a modular platform for the HIL system. Using the NI VeriStand API, we created a custom LabVIEW application for the user interface to provide even greater flexibility.
Developing the Real-Time Software Application
NI VeriStand and real-time PXI offer deterministic control with real-time data logging. The NI VeriStand INERTIA real-time control add-on provided multimode proportional integral derivative support that facilitates dynamic switching between temperature, pressure, and flow control mode.
Using the NI VeriStand plug-in architecture and out-of-the-box features, we created application-specific hardware and software functionality. These plug-ins are fully integrated throughout the application, with the same deterministic performance as other NI VeriStand features. We created plug-ins for enhanced alarming functionality (Alarm Matrix) and the vehicle system controller (VSC) that emulates target ECU outputs. Both of these plug-ins perform critical functions that require real-time condition response.
The Alarm Matrix plug-in monitors channels and the vehicle system state. Based on definable alert levels and the vehicle system state, the Alarm Matrix performs actions and mitigates VSC system outputs. The VSC plug-in simulates the vehicle ECU, acting as a gateway for the fuel cell system. The VSC is responsible for accepting power and cooling requests from the fuel cell system, verifying system condition to provide requested levels, and requesting the desired levels or reporting back to the fuel cell system via the CAN bus.
Interfacing With Vehicle Models
We used NI VeriStand to interface with custom NI LabVIEW code, models developed in MathWorks, Inc. MATLAB®, and compiled models created in other development environments. We uploaded a CAN database inside the NI VeriStand environment and linked the signals to model outputs. When the model runs, it performs real-time logic to ensure that an electronic load is in the correct state.
In the next iteration, Ford selected Dynacar, an NI VeriStand add-on for full vehicle simulation that you can use to select the target vehicle where the fuel cell will be implemented. Ford engineers can use pull-down menus to configure the simulator to closely replicate the target vehicle without requiring complex models. By adding Dynacar to the system, the Ford Fuel Cell Development Team can use the hardware necessary to include an actual driver in the loop. This means they can evaluate the system in a vehicle under actual driving conditions without leaving the test stand.
Customizing the User Interface
We created a custom LabVIEW application to dynamically configure NI VeriStand and provide the user with an array of tools and I/O screens that display on demand based on the number of monitors connected to the system. These screens and tools provide customized GUI functionality and displays that Ford needs for the application, and they also provide interaction with NI VeriStand functions such as channel configuration, calibration, calculated channels, and test profile generation.
Quickly Changing Sensors for New Fuel Cells
The sensors used with each new fuel cell vary from prototype to prototype, so a primary test stand requirement was seamless sensor change. Sensor feedback is crucial to understanding fuel cell interaction in conjunction with test stand operation. To understand this relationship, it must be logged and synchronized with the test stand data. Using an EtherCAT distributed I/O chassis, we can change sensors and wire them to the chassis before the fuel cell is brought into the test cell. Therefore, the test stand can operate while a technician wires the next fuel cell to be tested, which saves time and resources. It also means we can update each new fuel cell’s sensor list through the EtherCAT device settings inside NI VeriStand.
Consistently Delivering Complex Test Solutions
Wineman Technology, working closely with National Instruments and Ford Motor Company, provided an intuitive solution for a very complex alternative fuel vehicle application. Our long history of developing high-performance real-time control and data acquisition systems, close relationship with National Instruments, and in-depth knowledge of NI real-time hardware and software platforms helped us deliver a very advanced, powerful, flexible, and user-friendly system that achieves all Ford Motor Company test system requirements.
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Michael P.C. Cornwall
Wineman Technology, Inc.
1668 Champagne Dr