Electric Experimental Vehicles

The electric mobility research group at MRM operates two electrified experimental vehicles, especially for assessments of centralized vehicle operation management with integrated driving safety functions. These are a Mercedes Benz C-Class passenger car converted to electric all-wheel drive as well as an electric moped extended with an all-wheel drive power train.

Contact

Dr.-Ing. Michael Buchholz
Room: 41.2.219
Phone: +49 (0)731 50 27003
E-mail | Homepage

EVA-MRM

The "Electric experimental Vehicle with All-wheel drive at MRM" (EVA-MRM) was built by the Institute of Measurement, Control and Microtechnology (MRM) on bases of a Mercedes-Benz C class in collaboration with a company specialized in electric vehicle conversion. The power train consists of one electric motor per wheel, which can be controlled individually depending on the momentary driving situation and the driver's set-points. Thus, steering can be supported by the power train ("active yaw" or "torque vectoring"), which can, for example, be used to improve cornering stability. The driving torques are calculated by a real-time optimization algorithm on a rapid-prototyping control unit. This control unit has access to all relevant vehicle systems including the mechanical braking system. The experimental vehicle has an official approval and homologation for road service for test drives in regular traffic.

The experimental vehicle has the following technical charateristics:

  • Vehicle base:
    • Mercedes-Benz C 250 CDI 4MATIC BlueEfficiency T model (S 204)
  • Independent all-wheel drive:
    • Front wheels: induction machines
    • Rear wheels:  synchronous motors
    • Each with clutchless transmission with fixed ration
  • Battery:
    • 104 lithium iron phosphate cells in series connection
    • Nominal voltage: 330 V
    • Nominal capacity: 33 kWh
  • Mechanical braking system:
    • Blending of mechanical braking and recuperation by braking pedal with electric simulator unit
    • Access to mechanical single wheel braking by rapid-prototyping control unit (brake-by-wire)
  • Vehicle Control:
    • Freely programmable base ECU with standard operation software
    • Rapid-prototyping control unit MicroAutoBox by dSPACE for testing and evaluation, allows for take-over of single or all control tasks from the base ECU
    • Access to all relevant vehicle systems and data
  • Operation conditions/approval:
    • Test vehicle approval and homologation for road test in regular traffic in Germany
    • Prepared for additional equipment like radar sensors of cameras

If you are interested in our experimental vehcile for research projects, a detailed specification is available upon request.

Picture of the experimental vehicle EVA-MRM (red Mercedes C-Class)
Experimental vehicle EVA-MRM
Picture of the experimental vehicle with open bonnet
Engine compartment of the experimental vehcile EVA-MRM
Picture of one of the vehicle's battery packs
Battery pack
Picture of charging outlet of the electric experimental vehicle EVA-MRM with plug
Charging of the electric experimental vehicle

All-wheel Drive ELMOTO

The motorcycle with electric all-wheel drive was built within the project "Sicherheitsfahrwerk mit Elektro-Allradantrieb für E-Bikes & E-Motorräder" (Safety chassis with electric all-wheel drive for electric bicycles and motorbikes) with the help of the project partners GIGATRONIK Technologies GmbH (Ulm), ID-Bike GmbH (Stuttgart) and ipdd GmbH & Co. KG (Stuttgart) and with funding by the Ministry of Economic Affairs, Labour and Housing Baden-Württemberg. Starting with the electric moped ELMOTO HR-2 by ID-Bike, the all-wheel drive was realized by integrating an additional front wheel motor and it's dedicated inverter. A supercapacitor module in addition to the built-in battery allows for recuperative braking of the experimental moped. Supervisory control is provided by a rapid-prototyping control unit, which - besides others - applies a situation-dependent torque distribution for acceleration and braking using real-time optimization. To fulfill this task, an estimation of the momentary driving state is performed and the loss characteristics are taken into account for efficiency reasons. The experimental vehicle has an official approval and homologation for road service for test drives in regular traffic.

The all-wheel drive moped has the following technical charateristics:

  • Vehcile base:
    • ELMOTO HR-2 by ID-Bike
    • Maximum speed in regular traffic: 45 km/h (vehicle class  L1E)
  • Power train:
    • Additional motor (original hub motor of the rear wheel) at front wheel
    • Power all-wheel drive: 2 kW nominal / 4 kW peak
  • Hybrid energy storage:
    • Battery of the original electric moped
    • Supercap module for recuperation
  • Braking system:
    • Brake-by-wire via second turning handle
    • Recuperation with electric motors ans supercaps
    • Additional braking resistors
    • Electric control of the mechanical rear wheel brake
    • Original mechanical braking system still redundantly available
  • Vehicle Control:
    • Rapid-prototyping control unit: MicroAutoBoxder by dSPACE
    • Distribution of driving and braking torques by supervisory control depending on driving situation
  • Operation conditions/approval:
    • Test vehicle approval and homologation for road test in regular traffic in Germany
    • Driver and vehicle state supervision by additional sensors

If you are interested in our experimental vehcile for research projects, a detailed specification is available upon request.

Picture of the all-wheel drive motorbicycle
Experimental vehicle all-wheel-drive ELMOTO
Picture of a person riding the all-wheel drive ELMOTO
Test ride on all-wheel drive ELMOTO
Detailed picture of the supercap module of the all-wheel drive ELMOTO
Supercap modul for recuperation
Picture of the additional front wheel drive
Front wheel drive with brake calliper modification