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Advanced Architectures Chassis/Traction concept for Future Electric vehicles

Periodic Reporting for period 1 - ACHILES (Advanced Architectures Chassis/Traction concept for Future Electric vehicles)

Reporting period: 2018-12-01 to 2020-05-31

The global shift towards electric vehicles (EVs) is expected to achieve a tipping point in the following years. At a local level, EVs are able to improve the urban air quality by reducing emissions of pollutants while mitigating the noise. At a global scale, EVs help reducing GHG emissions. In addition to these environmental aspects, the technical advances made on electric motors and components during the last years have fostered the economic competitiveness of EVs.
However, the deployment of EVs still needs to overcome several significant technological barriers that slow down the market uptake, including limited driving range and less smooth dynamics in more demanding braking/acceleration events compared to conventional ICE vehicles. These are substantially influenced by the vehicle’s performance in terms of motion dynamics and braking strategy. Thus, regenerative braking is a key functionality in EVs with the capability of transforming kinetic energy back into electrical energy, charging the battery and hence extending the travel range. Improving the regenerative brake towards a fully electric drive control is still a challenge. Its integration with active torque control vectored separately to each of the wheels enables enhanced motion dynamics that further increase the energy efficiency and reduce the weight. In addition, these improvements will enhance the driving experience, increasing the user comfort and safety, favouring the mainstream adoption of EVs for the consumer.

ACHILES focuses on developing a new E/E control system architecture that integrates the next generation of e-brake and e-drive functionalities and paving the way to finally integrate such functionality in a centralized domain energy control unit concept. The advances proposed will significantly reduce weight, system complexity and cost while increasing reliability, users comfort and safety/security aspects.

The goal of ACHILES is to design, model, manufacture and test a novel E/E architecture that will allow to:
• Reduce the total cost of ownership by 10%;
• Increase the driving range by at least 11%;
• Increase autonomy with respect the centralized computer driving unit and braking system; compared to a benchmark existing EV.

In particular, four new technological concepts are developed:
• A new wheel concept design will be equipped with full by-wire braking, including a new friction brake concept;
• A centralized computer platform to host the edrive functionalities and reduce the number of control units and networks while fulfilling safety & security requirements;
• An out of phase control that allows to intentionally operate the electric motor inefficiently to dissipate the excess of braking energy in case of fully charged batteries;
• A new torque vectoring algorithm to significantly improve the vehicle dynamics.
The following activities have been performed in the first period from M1 to M18:
• Full definition of the vehicle specifications and requirements for fulfilling the project objectives;
• Definition of the test procedures at component and vehicle level to guarantee the ACHILES vehicle performances in terms of targets for future EVs and project KPIs;
• Definition of the vehicle control architecture and Central Computer Platform (CCP) interface;
• Modelling and control of the powertrain and battery system components;
• Development of safety concepts for the ACHILES vehicle;
• Development of innovative torque vectoring algorithm;
• Design of the new wheel concept and brake system, including out-of-phase control, together with the powertrain components.
• Planning for the vehicle integration, first at virtual level and then at physical level into the actual vehicle. Both preliminary testing on the baseline vehicle at IDIADA facilities and testing plan have been defined.
Achiles will develop four new technological concepts in order to take the work beyond the state of the art:
• A new wheel concept design will be equipped with full by-wire braking, including a new friction brake concept;
• A centralized computer platform to host the edrive functionalities and reduce the number of control units and networks while fulfilling safety & security requirements;
• An out of phase control that allows to intentionally operate the electric motor inefficiently to dissipate the excess of braking energy in case of fully charged batteries;
• A new torque vectoring algorithm to significantly improve the vehicle dynamics.

The impacts and results foreseen within Achiles are presented below together with the current status after Period 1:
Impact 1: ACHILES will be able to increase the driving range to at least 11% and decrease the yearly energy consumption per km. This will allow to save up to 24 GWh per year for the 2026-2030 period.
So far, Achiles has developed a new torque vectoring algorithm for enhancing the motion control and an optimized novel friction and regenerative e-braking concept and defined the detailed requirements for reducing the energy consumption.
Impact 2: ACHILES innovations will be able to reduce the cost of components and sub-systems by: i) introducing a centralized domain controller architecture (CCP) compared to the efforts needed when installing decentralized individual control units; a potential saving in cost up to 20% is targeted on top of the complexity reduction and the lower susceptibility to electromagnetic compatibility and security; and ii) by introducing an out of phase concept in the e-motor which will allow removing brake resistors and hence reduce cost.
Impact 3: ACHILES innovations will extend the operational range w/o recharge by up to 15% at some operating conditions by enhancing efficiency of regenerative braking in order to recover more energy, with an affordable battery size. With the new braking concept incl. regeneration and the optimized control architecture developed in this first period the autonomy of the vehicle is increased without increasing the size of the battery pack or changing the charging process.
Impact 4: ACHILES new wheel and brake concept will enhance understeering and oversteering behaviours by improving the blended braking of current EVs, improving the vehicle stability and enhancing the comfort thanks to the smooth electric control and management during driving. Also, the maintenance and replacement schedules and costs will be reduced, while the security and safety will be enhanced. To this end, ACHILES project has already designed the new wheel and brake system concept, resulting in reduced cost and maintenance, which is being prototyped. Safety and security levels have been considered within the new concepts and are being evaluated.
Impact 5: ACHILES innovations will be fully tested in two demonstration platforms and demonstrate that the driving range is increased compared to the baseline vehicle.The new concepts and technologies will be implemented in the demo vehicle.
Impact 6: ACHILES aims to contribute in the EV adoption, which will allow to cut CO2 emissions with respect to the use of ICE vehicles. By developing the new technologies considered in this first Period, ACHILES increases the vehicles efficiency and decreases the CO2 emissions significantly. In addition, there have been active dissemination activities and collaboration with the EVOLVE cluster towards a fast adoption of EVs, further addressing environmental, societal and health issues.