EVisionTM - Universal Monitoring and Measurement Instrument
for pure Electric or Hybrid Vehicle or Boat

Updated Dec 04 '2009


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METRIC MIND ENGINEERING PRESENTS

EVisionTM is sophisticated instrument which allows to monitor, accurately measure and record many parameters related to a traction battery. It is designed primarily for use in electric vehicles, but since it is primarily a battery performance instrument, it can be used in an electric boat, bus, motorcycle, any type of hybrid vehicle, or in general in any application (including stationary) where its battery parameters have to be monitored.

As a vehicle instrument, it meant to replace e-meter type of gadget and thus provide many more functions and flexible user configurable display options while getting rid of numerous e-meter shortcomings. EVisionTM not only acts as a "fuel gauge" of an EV or HEV, but also tracks (and logs with external PC) about 15 different parameters. Any three parameters can be displayed at once - two using digital readout (two 3 digit 7-segment LED displays) and one - using 25 segments analog bar. User can assign any 3 of about 15 parameters to any of 3 displays (where respective unit identifiers are available) to be displayed at once, creating custom "page". 20 such combinations (pages) are stored in memory and can be selected at the touch of remote rotary encoder switch. In addition, EVisionTM is equipped with vehicle's stock analog fuel gauge driver allowing using for instance existing fuel gauge on the dash as traction battery SOC monitor. The instrument is powered solely from the traction battery pack via internal isolated DC-DC converter and does not require any other external power to function. It will monitor and display status of auxiliary onboard 12V battery, but does not require it as a power source. EVisionTM is equipped with galvanically isolated standard RS232C serial interface for capturing streaming data, configuring unit and update the firmware. All parameters and values are date/time stamped and continuously streamed out in NMEA ASCII format whether acknowledged/captured or not. Corresponding software with GUI for a PC is included, however because it is only an interface for serial comm routines and actually Windows HyperTerminal handles communication, identical job can be performed using any serial terminal software such as Z-terminal for Mac or any serial comm. pack for Linux.

Here is the testimonial of the first beta tester John Wayland who installed and evaluated EVisionTM in his White Zombie - first world's quickest street legal electric drag racing vehicle.


Specification for pilot pre-production units is listed below.

Measured and displayed parameters:

Traction battery

  • Instantaneous voltage, V
  • Instantaneous current in or out, A
  • Instantaneous power in or out, kW
  • Running capacity balance, Ah
  • Running energy balance, kWh
  • Present SOC, %
  • Temperature (highest of 2 zones), °F or °C
  • Indication of direction of battery current, OUT (drive) or IN (regen or charging)
  • Cycle life counter, full cycles
  • Traction battery imbalance detection and measurement

Auxiliary 12V battery:

  • Instantaneous voltage (V)

Vehicle:

  • Current vehicle speed1,2
  • Energy consumption, Wh/mile and/or miles/kWh2
  • Odometer2
  • DTE (Distance to empty) estimation2
  • TTF (Time to Full) estimation in charging mode
  • Indication of charging status
  • Night time display dimming and HMI illumination
  • Sleep with wake up on ignition or charge
  • Automatic drive/charge/idle mode detection
  • No power consumed from onboard auxiliary 12V battery, no such battery is required for full functionality.

Instrument

  • Streaming running data out from the serial port
  • Download and Upload instrument configuration parameters, user preference, battery and vehicle parameters
  • Long retention of internal RTC setup for correct time stamping without power applied (~ 1 week).

External controls:

  • Stock analog fuel gauge drive
  • Charger disconnect after predefined charge is completed

EVisionTM consists of at least 4 sub-blocks - main controller, HMI (remote user interface via rotary encoder) shunt measurement PCB and external or in-dash display. Optional speed sensor is required for efficiency and distance estimation calculations. Inter-component communication is implemented via CAN bus. Front end measurement hardware is based on BRUSA Ah counter shunt and measurement PCB to maintain backward compatibility with legacy BRUSA Ah counters. Thus existing BRUSA Ah counter owners can keep their measurement board with shunt and upgrade only EVisionTM display and main controller. Display comes in 2 flavors: external in a spherical enclosure and internal - without enclosure (for in-dash integration). 12V auxiliary battery voltage is monitored, but not used to power EVisionTM. In fact 12V power doesn't have to be present for proper instrument operation. The power is supplied directly from the main traction pack and the power consumed is about 2 W in running mode and about 300 mW in sleep mode.

On this example of external display, vehicle efficiency (Wh/mile - US version) is configured for upper display, battery power (kW) - for lower display and battery relative state of charge (%SOC) - for the analog bar, acting as a fuel gauge. Relative SOC level is also outputted through the analog gauge driver as PWM signal.

1 US models display Imperial units (distance - miles, speed - MPH, temperature - °F) while EU models display metric units (distance - kilometers, speed - km/h, temperature - °C).

2 Speed sensor required (included with all M3 models).

 

Main electrical characteristics:

  Model M3-GR-US, M3-GR-EU M3-BW-US, M3-BW-EU
  Display color   Upper digital - green, lower digital - red,
  analog bar - yellow
  Upper digital - white, lower digital - blue,
  analog bar - white and blue
  Measured battery current range   0.01...250A or 0.02...500A in or out standard.
  (Custom shunts for higher current up to 2,500 battery amperes readout     are available. Resolution and accuracy reduced proportionally)
  Measured traction battery voltage   80...400 VDC continuous, 500 V peak.
  Measured aux. 12V battery voltage   0...16 VDC
  Measured traction battery capacity   0...999 Ah
  Measured traction battery energy storage   0...999 kWh
  Measured traction battery relative SOC   0...100%
  Measured traction battery power   +/- 0...650 kW
  Measured temperature   -35°C...+99°C
  Full charge cycles counter   0...65535 cycles
  Vehicle speed displayed   0...999 MPH (US),  0...999 km/h (EU)
  Trip odometer max value   999 miles (US),  0...999 km (EU)
  Power supply current (from traction pack)   6 mA @ 350VDC, 20 mA @100 VDC (running mode, no optional expansion module)

 

Display unit dimensions

External display In-dash display

 evision_round_front-s.gif (3454 bytes)

evision_round_side-s.gif (4116 bytes)

evision_indash_face-s.gif (3674 bytes)

evision_indash_top-s.gif (1405 bytes)

 

Model selection matrix guide:

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Model comparison table:

   Parameter

M2 model M3 model
  Efficiency live data available   No Yes
  Analog fuel gauge driver available   No Yes
  Vehicle speed data available   No Yes
  Data streaming via serial interface   No Yes

  

 

Please NOTE: Currently only following models are available in pilot production:

MMC-M3-N00-GR-US, MMC-M3-N00-GR-EU
MMC-M3-N10-GR-US, MMC-M3-N10-GR-EU
MMC-M3-300-GR-US, MMC-M3-300-GR-EU
MMC-M3-310-GR-US, MMC-M3-310-GR-EU
MMC-M3-400-GR-US, MMC-M3-400-GR-EU
MMC-M3-410-GR-US, MMC-M3-410-GR-EU
MMC-M3-500-GR-US - special order, subject to additional lead time
MMC-M3-510-GR-US - special order, subject to additional lead time
MMC-M3-500-GR-EU - special order, subject to additional lead time
MMC-M3-510-GR-EU - special order, subject to additional lead time

 

December 2009 UPDATE:

Pilot pre-production of 80 units was completed by the end of November 2009 and EVision proved to be very successful EV instrument on the market. Therefore MMC transitions to a production mode of about 500 improved units available throughout 2010. Therefore pilot pre-production units are no longer available and new model is scheduled for release in January 2010.

Main improvements of new production EVision include:
- New LED display appearance - now user can request any RGB color display with standard being blue and white.
- Dual shunt measurement circuitry improving accuracy of tracking relatively low charging current (0...40 A and 0...100 A ranges) while extending measurement range of drive/regen current to 4,000 A.
- Widest in industry traction battery working voltage span - 65...900 VDC is handled.
- Noise immune fiber optic link between shunt measurement unit and main controller/display improves safety and robustness for high power applications (sport performance or drag racing EVs, trucks/buses, etc)
- Addition of "favorite" buttons allowing quickly get to the home page and increment/decrement pages thus eliminating need to use rotary encoder. Either (or both) control methods can be used.
- Addition of opto-isolated charger control output
- Addition of optoisolated programmable power steering control output

Firmware and documentation downloads (applies to pilot production units only):

  EVision Set Up software for MS Windows (s/n prior to 50, 1.8MB zip file)
  EVision Set Up software for MS Windows (s/n 51 onwards, 2.1MB zip file)
  EVision main controller (SOCM) firmware (s/n 51 onwards, 106kb zip file)
  EVision Display (DD) firmware (s/n 51 onwards, 57kB zip file)
  User's manual download (draft, v 0.9.12, 768 kb pdf file, units s/n 51 and greater)
  User's manual download (draft, v 0.9.08, 1.3 Mb pdf file, units s/n 1...50)
  EVision NMEA serial data string fields definition (14 kb pdf file)
  RS232 streaming data string example (v3, 10 kb pdf file)
  CAN frame signals info (41 kb pdf file)
  CAN node TX signals info (16 kb pdf file)
  CAN node RX signals info (22kb pdf file)
  CAN frames info (37kb pdf file)
  CAN network info (10 kb pdf file)
  ECUs info (10 kb pdf file)

  Datapack for capture/plot utility developers

 

  Unit conversion page
  Price list



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