9

Crash-test prototypes

Our crash testing programme for global homologation is so rigorous that nine out of 17 C_Two prototypes will be crash tested in three phases.

Design and simulations

The design process is long and complex: we start with a rough concept which is virutally simulated. Once we’re happy with the result, our design and engineering departments refine the model.

The C_Two monocoque is the biggest carbon fiber single part ever produced in automotive industry.

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Everything from the active front splitter and intelligent underbody air flaps to the adaptable air brake is designed, developed and tested to perfection in-house, the Rimac way.  

Development has been performed in the loop triangle between:

Computational fluid dynamics simulations

• We’ve performed more than 1000 simulations just for the external aerodynamics
• Each simulation model consists of over 120 million elements with up to 180 million for the detailed heat transfer models)

Wind tunnel testing

• Drag coefficient is correlated within 2.4%
• More than 100 components were exchanged during the tests to confirm the correlation and characteristics between the CFD simulation results.

Track testing

• The active aerodynamic system adapts to a chosen driving modes in less than one second
• In Track Mode, the air brake actuates in 0.3 seconds

34%

Aerodynamic efficiency improvement

From the initial C_Two concept to the validation prototype, as a result of continuous optimisation, aerodynamic efficiency has been improved by 34%

C_Two aerodynamic profile variations:

• In Range Mode drag is reduced by 17.5% when compared to the Track Mode. 
• Shifting from Range to Track Mode increases downforce by 326% 
• High speed configuration (DRS) reduces drag coefficient by 10%  while keeping balanced downforce. 
• The fully extended rear wing increases rear radiator mass flow by 7.7% 

C_Two has the largest differentiation on drag and downforce coefficients which means it’s able to meet Range and Track performance targets with a simple driving mode change.

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Vehicle Dynamics development starts by defining the target weight, dimensions and desired suspension settings. After the tyres have been selected and the suspension hardpoints are set, we start to aim for the targets. Once the kinematics are defined, 15-depth of field and multibody simulations are conducted to define the parameters of the springs, dampers, antiroll bars and bushings. 

41

Seconds

Is how long the driver is braking with more than 0.8G during one Nürburgring lap in C_Two.

249

Degrees of freedom

Used in full vehicle Multibody System model in Kinematics and Compliance simulation

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After setting the targets acceleration, top speed and lap time – the choice of tire dimension and model was one of the most crucial decisions.

Numerous vehicle dynamics simulations were done with physical and empirical tire models. Those models used in simulations are provided by Pirelli from the tire test machines data, the same they used for FIA Formula 1 indoor testing.

2.8x

Times more load

During braking, the front tire is loaded 2.8 times more than the rear tire.

Once the vehicle architecture was entirely defined, our simulation and performance team gave detailed requirements to Pirelli for achieving target vehicle balance, longitudinal and lateral performance. The closed development loop between Pirelli and us includes simulations of maximum loads generated by aerodynamic force, or downforce.

Based on the latest tire requirements, Pirelli is building an indoor test prototype tire. The stage of tire development by testing of prototype vehicles. During the test sessions on the proving grounds and track, test and development drivers select the best prototype tire. After the latest iteration and test session, Pirelli starts the process of industrialization and homologation, preparing for serial tire production.

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By reading the road ahead – using the car’s nine onboard cameras, LIDAR, radar and 12 ultrasonic sensors – the on-board supercomputer calculates the optimal level of torque to deploy to each independently driven wheel over 100 times a second. 

19k

Simulations

Were conducted prior to 1000 hours of in-vehicle algorithms fine tuning

Taking inspiration from the natural world, like the Cheetah’s ability to change direction in a split second, our system is capable of adjusting the torque output of each motor in both directions – acceleration and braking – resulting in exceptional levels of agility and control.

Compared to conventional systems, where hydraulic brakes are used to stabilise the vehicle, the R-AWTV makes use of all four electric motors to aid braking, replacing the need for ABS and ESP systems.

While conventional drivetrains are hindered by their slow reaction times and inability to control each wheel separately, our system develops levels of grip never seen before. More stable and safe while enabling a more agile and dynamic driving experience, R-AWTV allows the car to be configured in infinitely different ways, for any given situation.   

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The system is capable of evaluating and analysing ability its surroundings and the car’s state in a split second, calculating the right trajectory and vehicle commands and executing them in real time. The driver receives audio and visual instructions are fed through the car’s speakers and displays.

Created and designed in-house, the development of the system has so far taken place over three years by our team of scientists, software engineers, test drivers and psychologists. Together, they have built the whole system – conducted everything from phycological analysis and computer simulations to real-life, on-track testing using development mules.

3

Years

The amount of time spent developing and testing the system to date

6

Terabytes

The amount of driving data collected by the car per hour, the equivalent of 1.68 billion photo files

Linked to the web, the system shares the performance and achievements of the driver with other users, creating an online Driver Coach community. Through users driving on different tracks, the system records the session data to compile an accessible track complexity index, which ranks the difficulty of various racetracks all around the world.

The post Driver Coach appeared first on Rimac Automobili.

1k

Arms/motor

Maximum motor current (10 sec peak)

The performance, mass and dimensional requirements could only be met using Rimac development methods.

The post Inverter development appeared first on Rimac Automobili.

28

m/s

of circumferential speed (18000 rpm) on Input Shafts Radial Seal 

Each component in our C_Two Gearboxes is pushed to physical limits with materials and components currently available on market. 

The post Gearbox development appeared first on Rimac Automobili.

The development of components starts with initial requirements, drawings, and calculations. Each new design is checked with simulations. The knowledge obtained from the results is implemented then into a new iteration of the design. This fast development process leads to components that are reliable and once real-life tested perform as planned.

14

System parts in our battery cooling system

Our Battery cooling system model consists of 38850 elements, 204734 scalar equations and 14 main system parts: Heat exchangers, HVAC, pipes, joints, splits, valves, pumps, battery modules, and control algorithms in one model to ensure top performance on both road and track.

The post Components development: Structural Analysis appeared first on Rimac Automobili.

Custom infotainment OS and rich in-vehicle applications, telemetry system capable of monitoring storing and analysing data from thousands of vehicles simultaneously and mobile phone applications capable not only to provide information about your car but also giving you the power of control are just some of the sexy things going out of Software Department. 

Having whole software stack?development?under one roof?by using cutting-edge technologies makes us?flexible, fast, and innovative?lettings us pushing the boundaries between possibilities & imagination.?Software?is?the one responsible for?bringing the Connected?prefix to Vehicle?term?and the one?breathing?life into an electric monster.?

30 commands for controlling the vehicle via mobile app

500

Functionalities

There are over?500?functionalities in the C_Two infotainment?system.

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