CrossChasm Embedded Control Systems Whitepaper For Powertrain Design Teams Background For vehicle design teams looking to rapidly develop and field early stage vehicle prototypes, a typical problem is developing low-cost control systems within the tight timelines of the program. These control systems are used to coordinate powertrain components on the vehicle, and as CANbus or I/O gateways to allow fast integration of off-the-shelf components. As the vehicle development program matures from prototypes into more refined early-stage fleets, the functionality contained within these controllers typically gets amalgamated into other on-board controllers, and the rapidly-developed software turns into a functioning rough-cut specification for the production software teams. crucial to design the software to maintain operational safety even during the transitional startup calibration and validation process. CrossChasm has a deep pool of knowledge and experience developing in-vehicle control systems. From battery-electric to hybrid vehicles, from engine management systems, to hybrid snowmobiles: CrossChasm has integrated dozens of successful prototypes for its clients. To develop these types of controls in the short amount of time typically demanded by management, a specific type of engineering team is needed: multi-disciplinary with deep vehicle systems integration knowledge, and the ability to write quality software with a high level of inherent implicit safety. The safety aspect is key: both during normal vehicle operation and more importantly, during initial startup and calibration. It is
Why CrossChasm Rapid prototype control (RPC) systems are named so for a reason: they can be extremely quick to develop. Typically this is done by centering the development team around: 1) Laser sharp focus on project delivery using high quality hardware and a proven development tool-chain 2) Team knowledge around identification of critical systems and mitigating systems design 3) Knowledge and application of industry best practices. 4) Existing software modules to reduce spin up time. 5) Deep connections with quality component suppliers Development of modern rapid control systems is occurring in a Matlab/Simulink environment, where the modularity of the Simulink software blocks can dramatically reduce the time required to spin the wheels. Further, the use of pre-generated library blocks is typically used as a way to make use of previously developed and validated software. The Matlab/Simulink environment also provides script-ability: instead of software programmers writing tedious implementations of very similar code, often scripts are written above the Simulink layer that will auto-populate the Simulink diagram with library blocks and auto-route Simulink wires; in effect the scripts write the embedded software for the engineers. CrossChasm puts this concept to use when developing CANbus gateways for its clients vehicles. Using a set of custom m-code scripts operating on the Simulink diagram, the system opens the CAN network database file (.dbc), pulls out the necessary information to decode the raw frames, encodes that information into the CrossChasm CAN Read and Write library blocks, and populates the right number of blocks into the diagram. This process only takes a few minutes, and all the data on the CANbus is available to the control code, and the right messages are being written (with default values) to the CANbus. While there are standard products on the market that can be configured to perform simple CAN message gating functionality, the ability to tightly control the timing and delay of critical messages is important to avoid setting U-code faults in automotive controllers. Building high quality CANbus gateways with high fidelity timing can be the key to a project. Other Examples Engine Management System In 2009, Westward Industries contracted the development of its hybrid vehicle s engine management system to CrossChasm. CrossChasm, partnered with MotoHawk Control Systems, built a custom engine management system including electronic
throttle control, spark control, fuel control, evaporative emissions, and PID speed control. The software was designed in such a way to allow the Hybrid Supervisory Controller to manage the power output of the engine in coordination with the generator inverter torque commands. Most importantly, the use of rapid control systems and the pre-built library of CrossChasm software components allowed the system to be up and running on an engine dyno within a few weeks. Westward later partnered with CrossChasm to collect in-vehicle usage data from their already deployed vehicles in selected cities and understand how the duty cycles of those vehicle s should impact the design and calibration of their hybrid control strategy. Since their vehicles were sold into a very specific use case (parking enforcement), it wasn t appropriate to calibrate the hybrid strategies against standard automotive drive cycles such as the US06 or FTP-75. Instead, CrossChasm provided OBD2 data loggers to monitor a sample of vehicles to develop a Westward specific drive cycle. These cycles were then used to pre-calibrate the engine and hybrid control strategies before the on-road calibrations were fine-tuned for drivability. Program-Specific Test Equipment In 2011, CrossChasm developed a low-cost fault injection system that would allow the functional safety test engineers on the Ford Focus EV program to understand the impact of invalid CRCs, quality factors, and rolling counters; features that provide protection for high integrity CANbus signals. This system allowed the engineers to isolate the motor controller onto a private CANbus network, gate the messages from the powertrain control module residing on the main vehicle CANbus to this private network, and to modify the signals as they went by. This technique was used to provide evidential proof that the CAN fault mitigation strategy was functional within each control ring before vehicle release. Since CrossChasm uses Matlab to script the generation of control code, the development of a development program - specific module that can done in a matter of days, with low associated costs, in a package that can be easily integrated under-hood. High Bandwidth Powertrain to Platform CAN-to-CAN Gateway For prototype vehicle development teams, who wish to quickly integrate pre-existing controllers, and components into vehicles without going through the process of reengaging their software teams to re-write their signal code can make use of interface modules. A typical use for such modules can be to enable teams to implant a powertrain from one vehicle into a wholly incompatible host platform. CrossChasm
has successfully used this technique to enable the integration of batteries, motors, powertrain controllers, and a wide variety of other powertrain equipment into systems that they were not originally designed for, including Ford powertrains into GM vehicles, stationary fuel cell systems into road-worthy SUVs, and forklift motor drives into off-road vehicles. These systems have two critical features: gateway-ing, and packaging not only CAN messages across networks with millisecond-level accuracy, but also proving the right set of inputs and outputs to drive the startup/shutdown sequencing for the various systems within the vehicle and all the various algorithms that are necessary to interface the unique moding and sequencing inherent to each component. The Team CrossChasm s powertrain simulation team is headed by Alexander Koch and Chris Mendes. Alexander Koch leads the embedded controls group at CrossChasm. He has a Masters Degree in Mechanical Engineering from the University of Waterloo with a special focus on Hybrid Powertrain Controls. He has led a wide variety of controls projects in his career, including control systems integration of Fuel Cell Hybrid vehicles, battery-electric vehicles, Range-Extended Hybrid vehicles, as well as autonomous rover platforms and accessory electrification. He is an expert on in-vehicle networking, and CANbus fault mitigation strategies, and previously worked on Ford electrification programs. Chris Mendes is co-founder and CTO of CrossChasm Technologies. He holds a MASc in Michanical Engineering from the University of Waterloo with research focused on optimal torque vectoring control strategies for AWDvehicle and optimal hybrid control strategies. He is co-inventor of CrossChasm s model-based predictive total cost of ownership system which is the technology core of FleetCarma and MyCarma. He has a wide background in embedded software design, working on real-time control systems for autonomous vehicles, electric ATV s, fuel cell hybrid systems, engine controls, battery pack management, and vehicle systems integration. He is an expert on CANbus safety mechanisms and torque security, and contributed to the diagnostic and fault mitigation strategies in the Ford Focus EV. Would you like to learn more? CrossChasm partners with New Eagle to provide fully ruggedized and integrated control solutions to its clients. It also provides board level design and integration from the ground up. For more information about CrossChasm s Powertrain controls engineering services and how we can help you reach your design goals, contact us at sales@crosschasm.com, or visit us at www.crosschasm.com
About CrossChasm Technologies CrossChasm Technologies is a technology and solutions provider working to both design and help sell high efficiency vehicles through its various divisions: CrossChasm Engineering Services, FleetCarma.com (Fleet procurement and integration tools) and MyCarma (Dealership sales tools). CrossChasm Engineering Services works to improve the powertrain design process with companies such as Ford, GM, Magna Ecar, Toyota, Crown Equipment, Bombardier, New Flyer, NASA, Canadian Space Agency, among many other.