The automotive product design and the productization are a very complicated undertaking. The automotive product must meet hundreds of requirements to satisfy customers and conform to compliance standards, safety requirements and applicable government regulations combined with long lifetimes of projects.
“Modern vehicles carry more computation power than Apollo spaceship that flew to the Moon.”
The past few decades have witnessed an exponential increase in the number and sophistication of electronic systems in vehicles. Modern vehicles carry more computation power than Apollo spaceship that flew to the Moon. Many functions, such as navigation, infotainment or engine control cannot be implemented at all without an extensive use of electronics.1
A vehicle is a good example of a hostile environment for modern electronics. Electronic components are facing numerous interferences such as high temperature fluctuations, heavy vibration loads, high accelerations and decelerations, strong electromagnetic interferences, changes of the climate and environmental conditions, and the system should be immune to all these interruptions.
Short-term design phase with long-term impacts
Product Development Process can be divided roughly into three different phases; Definition and Design, Development and Validation and Manufacturing. The actual product design begins normally in the end of the definition phase when the main requirements of the product are nailed down and can be considered to end when the product design is ready for the first manufacturing release. On this blog post, we concentrate on the hardware (HW) design phase.
From the product life cycle perspective, the design phase is just a short period of time but the importance of its outcome is even greater. The maturity and quality of the first round of the design affect directly time-to-market and overall cost of development which in turn has consequences to the overall business case and the customer satisfaction. That’s why we want to be confident about the product quality and that the product will fulfill the requirements with a great probability even before burning a pile of money by building the actual prototypes.
Here our intention is to look more closely the time between the start of the detailed design and the finalization of the design files. This is the period in which the experienced HW engineers give a physical form for a product, taking into account all regulative, customer, legislative and internal requirements – and all these must be done with the utmost care. This is also a kind of a point of no return from the investment perspective and a good place to push a brake pedal if there are too much uncertainties.
The carputer design requires a close cooperation between many stakeholders. Once the maturity of the system design is high enough, key component selections are made and we have a good understanding about the product architecture, the actual design work can be started. The design phase takes normally three to four months, and this is the period when the magic happens. At the end of this phase, we have the first version of the final product in a digital form and the recipe for how to manufacture it.
Simulation helps to verify and validate the intended function of a product
In the design phase, it is still relatively easy and affordable to make design changes. But, how to find design flaws without a proper verification? Traditionally used fast prototyping and test & fix iterations are not feasible for such a complex system like a carputer. There are certain design areas that may benefit from using test boards but making a full-blooded prototype already in the design phase is not reasonable from the points of view of costs or schedules. Also, the software (SW) development goes hand-in-hand with HW, so it is unlikely that the overall system maturity is capable of enabling a full-scale verification at this early stage.
“Simulations are used to improve the design reliability before having the first functional prototypes in our hands.”
Therefore, we use simulations to improve the design reliability before we have the first functional prototypes in our hands. In recent years, an extensive research has been conducted in the simulation to model large complex systems and understand their behaviour. The simulation brings the greatest benefit in the beginning of the product development when there are still more opportunities to influence on the product design than later in the development. The simulation is also the fastest and the cheapest way to test design ideas without expensive prototyping. Fixing the problems after the first prototype rounds or even after the compliance testing is much more expensive and time consuming than fixing them during the design stage.
Even though the simulation is not a silver-bullet to tackle all the design flaws, it is a valuable tool to evaluate and verify the product architecture in the early stage of the product development. On the second part of the blog, I will present different simulations that are performed for the Motion T Carputer design.
1 M. Broy, “Automotive Software and Systems Engineering”, presented at 25th International Conference on Software Engineering, 2003, pp. 719-720