EV Electrical System Development With Generative Design

Automotive electrical and electronic (E/E) systems are becoming more complex, making the task of designing today’s cars much more difficult. Infotainment, comfort and convenience features, and even safety- and mission-critical systems such as steering and throttle control are accomplished through electrically powered computers, actuators, and sensors.

Electric vehicles (EVs) will only increase this challenge. All-electric vehicles do not have the support of a supplemental source of power such as an ICE. All the power the vehicle needs is supplied by the energy stored in the batteries. As a result, the number and sophistication of the electronic features on an electric vehicle has a direct effect on the drive range and performance of the vehicle. ADAS systems often incorporate cameras, radar, and ultrasonic sensors to enable lane departure warning systems, automatic braking, and more. These systems are a constant drain on the battery as they are always active.

Electric vehicle E/E systems

To enhance the efficiency of the E/E systems, and thus drive range, engineers will need to perform architecture and tradeoff analyses to investigate architectural proposals. The tradeoff analyses for an EV will need to account for hundreds of components and millions of signals while optimizing function locations, network latency, error rates and more. In addition, engineers will need to manage the high voltage lines that carry power to the electric motor, or motors (figure 1). These lines often require special design guidelines regarding routing and bundling that must be taken into account.

Fig. 1: High-voltage transmission lines for EV powertrains have special requirements around routing and bundling with other wires to prevent interference of other signals and ensure reliable powertrain operation.

Due to these unique design challenges, even major automotive OEMs will face problems that their legacy design flows are ill-equipped to handle. This will be true especially as companies move their electric vehicle projects from research, development, and one-off prototyping into full-scale production. The E/E systems will need to be optimized for cost, weight, and power consumption while adhering to the stringent safety requirements prevalent in the automotive industry. To compete, these companies will need a new design methodology that enables young engineers to design accurate and optimized systems, which can only be done by capturing the experience and knowledge of veteran engineers. They will need generative design.

Generative design & engineering

Generative design takes system definitions and requirements as input and generates architectural proposals for the logic, software, hardware, and networks of the E/E systems using rules-based automation (figure 2). These rules capture the knowledge and experience of the veteran engineers to guide younger engineers throughout the design. Capturing this IP helps companies to develop both vehicle architectures and new generations of engineers as they learn and implement existing company knowledge.

Fig. 2: Generative design uses rules-based automation to generate proposals for the logic, software, hardware, and networks of the E/E system.

A generative design flow begins with functional models. A functional model represents the functionality of the electrical system to be implemented, without specifying how it should be implemented.  It accounts for aspects such as communication networks, power sources, and components. These models may be captured in a variety of formats such as spreadsheets, SysML files, and MS Visio diagrams.

Design teams then normalize these various functional models into a unified format within their electrical systems design environment. Once normalized, the engineers can generate potential architectures for the E/E system logic, networks, hardware, and software. Valuable company IP is integrated automatically into these proposals through the design rules that govern proposal generation. At this stage, the electrical engineers can rapidly generate, assess, and compare multiple architectural proposals, optimizing the design from the initial solutions presented.

From the selected architectural proposal, the engineers can extract discreet logical systems to generate platform-level network designs and the electrical distribution system (EDS). With this in place, the team can synthesize wire harness designs for each subsystem, generate manufacturing aids and bills-of-process costs, publish electrical service data, and generate VIN-specific service documentation.

Why generative design?

The increasing E/E content of modern vehicles is already pushing current design methods to their limits, yet the complexity of automotive systems will only continue to grow in the future. Fully electric cars will contain incredibly complicated E/E systems. The drivetrain and critical systems alone will require a sophisticated system of computers, sensors, and actuators to manage battery charge and discharge, control systems, and the electric motors. What’s more, future electric vehicles will contain dozens of sensors, hundreds of ECUs, and miles of wiring to gather, process, and transmit the data required for advanced features. Engineers developing these vehicles will also need to balance performance requirements against power consumption, physical space constraints, weight, and thermal considerations.

Generative design empowers automotive engineers to tackle the challenges of E/E systems design for electric vehicles. It employs rules-based automation for rapid design synthesis, enables engineers to design in the context of a full vehicle platform, and tightly integrates various design domains to ensure data continuity.

Employing automation throughout the process will help design teams manage design complexity without increasing time-to-market. Automation helps engineers focus on the most critical aspects of the design and verification of the functionality of the E/E system and reduces errors from manual data entry. Automation also applies company IP to the generated proposals through design rules, increasing the accuracy and quality of the designs. Designing in the full platform context helps engineers to understanding the way signals, wires, and other components are implemented across the entire vehicle platform, thereby reducing errors at interfaces or due to the intricacy of the harness. This design flow also enables teams to re-use validated data across vehicle platforms to improve quality and reduce development costs.

Finally, a tightly integrated environment enables the electrical engineers to share data with engineers and tools in other domains, such as mechanical or PCB design. The interactions between the electrical, mechanical, and software components of a vehicle are increasing. Seamless synchronization of data between these domains improves the integration of them into a single system.

Electrifying the drive

Generative design will be a key enabler for new and established automotive companies as they develop all-electric vehicle platforms. The ability to generate electrical system architectures automatically enables early exploration and optimization of designs while embedding company IP into the design flow. Additionally, a singular source of data promotes consistency between domains, design reuse, and enhances the analysis of change impact. Finally, tight integrations between the electrical domains and with mechanical and PLM tools streamlines the entire design flow from conception through production.

The significant complexity inherent in electric vehicle design will continue to push the tools and methodologies used by automotive engineers. This is especially true in the E/E systems domains as they come to dominate the operation of a vehicle’s safety-critical systems and amenities. The winners in this disruptive technology will be those companies that can most effectively integrate the advanced technologies required for all-electric powertrains into a package that is reliable, safe, and attractive to consumers, and then get those technologies to market quickly and with a high level of quality.