The SilverStream project is developed to address the challenges associated with new technologies for future urban mobility. In particular, SilverStream will develop and demonstrate a radically new light and affordable vehicle concept (L-category) for the ageing population in congested European cities with scarce parking space.

The consortium has focused his attention, so far, on some  key objectives closely related to the development of the L-vehicle among the seven ones identified in the DOW :

• OBJECTIVE 1: Specifications related to the needs of urban and ageing population
  • (addressed in WP1)
• OBJECTIVE 2: Enhanced vehicle manoeuvrability for urban context
  • (addressed in WP2)
• OBJECTIVE 3: Sustainable ergonomics, health monitoring and adaptive HMI for minimum-fatigue vehicle operation
  • (addressed in WP2 and WP5)
• OBJECTIVE 4: Dual voltage 12/48 V power network for modular and scalable E/E architecture
  • (addressed in WP3, WP4 and WP5)
• OBJECTIVE 5: Hybrid energy storage system for extended operating life and increased efficiency
  • (addressed in WP3)
• OBJECTIVE 6: Compact in-wheel drive units for light urban mobility solutions
  • (addressed in WP4)

Objective 1

• coCreation is the research methodology implemented in the City of the Future Living Lab scenario. This research methodology has its roots in the renowned Living

Lab process, where the focus is on the users communities embedded within “real life” situations and environments.

Researchers involved in Living Lab activities work under FCSR Ethical Comittee supervision.

The process of User Requirements (Urs) identification and analysis has been based on a variety of tools, used in a complementary way, belonging to the Co-design phase approach. The set of tools include:

• Literature review
• Personas & Scenario (coCreation)
• User Surveys
• Interviews with field experts.

Following the analysis of the results obtained with the above mentioned tools, a preliminary list of raw URs has been prepared for each of the four area of interests (i.e. design, ergonomics, motor aspects and cognitive/emotive aspects).

Each  raw requirement has been analyzed and split in smaller requirements and categorized considering the following flow chart

A total of 67 User Requirements have been identified and reported in following format.

Objective 2

Large steering angles at the front wheels combined with torque-vectoring for reduced turning radius of < 3 m (30% less than a Renault Twizy) for easier parking and increased maneuverability.

Front suspension to be modified for SilverStream

Rear cameras to facilitate driving and parking. Images from the camera will be displayed on the HMI screen when the user select rear shift.  

• Reduction of motor drive power losses of ˜ 30% through variable front-to-rear and left-to-right wheel torque distribution
• Enhanced vehicle safety through torque-vectoring control with increased lateral acceleration limit of ˜ 5% and yaw damping of > 25% (technology transfer from the EU FP7 E-VECTOORC project)
• Wheel slip control functionality for low friction surfaces

Objective 3

• Lightweight seats designed for: i) optimal posture including lumbar and neck support for comfortable and low-fatigue driving; ii) easy egress and ingress through 90 deg swivel function
• Assisted rear e-lift (30 kg payload) for easy loading and unloading of the car
• Innovative HMI based on gesture recognition simplifying the operation of the auxiliary systems

e-seat and rear e-lift

• Based on ergonomic guidelines from FCSR, MTM is working to select a proper systems to handle the required seat movements. A roto-translation platform would be installed under the seat
• Furthermore a small crane has been selected to be installed in the rear boot

Roto-translation platform (L) and small crane (R)

• 3D Simulation of the movements have been performed to check the right integration of the e-seat in cabin
• At the moment a possible interference problem with the steering wheel has been identified and MTM is working on some suitable solutions

e-seat: preliminary study at MTM with SPARCO

HMI

The specifications of the communication between HMI and VMU are under definition, with particular respect to the integration of the CAN channel into the HMI system. In addition to classical infotainment functionalities, HMI will make available:

• vehicle information (speed, gear, …)
• an air condition system control panel (HVAC)
• a parking rear camera
• a debug section with information coming from powertrain (HESS, INVERTER, …) will be extremely useful during the vehicle development phase

HMI: preliminary architecture

HMI: prototype at JAC

• A possible solution regarding the integration of HMI<>VMU<>HVAC has been shared between partners( I&M, MTM and JAC). Integration of engineering information from powertrain is currently under development (both JAC and ELAPHE are involved in).
• A suitable rear camera has been selected and JAC is working on its integration in the HMI system.
  

Objective 4

• A native dual voltage (12/48 V) power network for safer and simplified E/E architecture
• Flexible E/E design to allow scalability across the L-category vehicles
• Multi-core processors for higher computational power and ease of system integration

E/E architecture (proposal)

The SilverStream electrical architecture is still under development based on the specification we are collecting from different partners contribution.

Vehicle Management System

A smart Vehicle Management System is under development (in the figure a similar system developed by I&M and IFX within the eDAS project).

The VMS will be in charge to manage all request from the driver and to coordinate different system in order to satisfy them.
It will receive command from HMI to control HVAC and all the other onboard actuator.
Moreover it will run torque-vectoring control strategy, developed at Surrey, and will provide the torque set-point to the powertrain.

HVAC

A proper way to integrate a novel concept based on heating pump for both cooling and heating the cabin has been selected. The system will be located in the engine bay and would be connected to the existing cabin ventilation body. The system would be controlled by the VMU based on temperature set point and other settings received from HMI.

HVAC in heating (L) and cooling (R) mode respectively

Objective 5

Various solutions of the HESS system are under investigation, including a different use of the SuperCap in order to simplify the 12V board-net and the design of the DC/DC /12/48V)

HESS with (L) and without SuperCap (R)

Objective 6

• 4-wheel-drive architecture for enhanced manoeuvrability, safety, vehicle dynamics and energy efficiency
• Lightweight (of < 5 kg) compact (of < 200 mm diameter and of < 100 mm axial length) efficient (> 92% efficiency) three-phase permanent magnet direct drive in-wheel motors (with 100 Nm peak torque per corner)
• Enhanced vehicle drivability (jerk reduction by 100%) and adaptable accelerator pedal response with the elimination of the torsional dynamics of the half-shafts
• Integration of electric motor and inverter for efficient and simple packaging

direct drive motors

In depth analysis of both in-wheel and near-wheel solutions have been performed by Elaphe