2019

HT04 on the Endurance track at Formula Hybrid 2019

HyTech's car at the finish line

Engineering Summary

For the 2019 competition year, our team continued our iterative design approach. We applied three design principles during our design of HT04: lightness, serviceability, and robustness.

Our weight decreased 45 lb (20 kg) compared to our 2018 vehicle, with a noticable weight reduction in each vehicle subsystem.

We greatly increased vehicle serviceability in a number of ways. We implemented an easy-to-install eccentric chain tensioning system as well as a drivetrain package that could be installed and removed from the vehicle without dissassembling. Quick disconnect brake lines allowed us to remove the pedal box or corners without having to rebleed brake lines. Our high voltage battery pack redesign featured easily removable panels and a busbar layout that reduced dissassembly and assembly time.

Our team found many ways of increasing the robustness and reliability of the new design. We designed a rigorous testing platform for our batteries, ensuring that each cell was reliable before assembling it in our high voltage pack. We retrofitted our new electrical system onto an old vehicle, allowing us to perform extensive testing early on in the development cycle. We also developed a new assembly process for our Battery Management System circuit boards, decreasing the failure rate and time spent on assembly.

Results

We won first place for the second year in a row at Formula Hybrid, placing first in the Design, Autocross, and Endurance events, and setting a record as the fastest electric team to ever finish the 44 km Endurance course. We also set our own personal record as this was the first competition where we successfully competed in every event.













HT04 Vehicle Details

General
  • Weight: 368 lb (166 kg) measured at Formula Hybrid
Chassis
  • Steel tube space frame
Suspension
  • Double unequal length wishbone
  • Ohlins TTX25 dampers
Powertrain
  • Chain sprocket reduction
  • Clutch type limited slip differential
Electric Drive
  • Motor: Emrax 207 Medium Voltage
  • Inverter: Rinehart PM100DX
  • Battery: 72S1P LiCoO2 pack with 5.8 kWh energy capacity
  • Peak output: 80 kW
  • Peak torque: 160 Nm
Electrical Controls
  • Low voltage controls: Power distribution module, telemetry and data logging system, and vehicle ECU integrated onto single PCB
  • High voltage controls: Isolated BMS utilizing Analog Devices LTC6804 chips and custom management software
  • Telemetry: Live vehicle data transmission via cellular network as well as onboard logging

2018

HyTech Racing at FSAE Electric 2018

HT03B on the track at Formula Hybrid 2018

In 2018, HyTech competed in both the Formula Hybrid and Formula SAE Electric competitions. Our team won first place at Formula Hybrid, placing first in the Design, Project Management, and Endurance events. We won sixth place at FSAE Electric, placing second in the Cost and Efficiency categories.

HT03B Vehicle Details

General
  • Weight: 413 lb (187 kg) measured at Formula Hybrid
Chassis
  • Steel tube space frame
Suspension
  • Double unequal length wishbone
  • Ohlins TTX25 dampers
Powertrain
  • Chain sprocket reduction
  • Clutch type limited slip differential
Electric Drive
  • Motor: Emrax 207 Medium Voltage
  • Inverter: Rinehart PM100DX
  • Battery: 72S1P LiCoO2 pack with 5.8 kWh energy capacity
  • Peak output: 80 kW
  • Peak torque: 160 Nm
Electrical Controls
  • BMS: Custom 5-board system utilizing Analog Devices LTC6804 chips
  • Low voltage control boards: Power distribution unit and dashboard/torque controller unit
  • Telemetry: Live wireless data visualization utilizing XBee modems













2017

HyTech Racing at Formula Hybrid 2017

In 2017, HyTech completely redesigned the mechanical and electrical systems on a new chassis, bringing the vehicle weight to under 380 pounds. We are proud to have taken first place in the design event at Formula Hybrid 2017.


2016

HyTech Racing at FSAE Electric 2016

HyTech Racing at Formula Hybrid 2016

This year HyTech designed and built our vehicle to compete in both Formula Hybrid and Formula SAE Electric competitions.

Chassis Details

  • Completely new team-designed frame
  • Torsional stiffness FEA: 2550 ft.lb/deg
  • MDF jig designed for efficient and accurate chassis welding

Driveline Details

  • Motor output (front) sprocket and rear sprocket designed and machined in-house
  • Front sprocket machined out of Aluminum 2024 to reduce weight (versus Steel) while maintaining a factor of safety >1
  • Hard mounted differential carriers machined out of Aluminum 6061; sticking to a robust and tested design
  • Motor mount manufactured from Steel 4041- reduces stress points, holds up to the maximum torque
  • Powered by the Enstroj Emrax 207 which is lighter than the other options in the market, yet powerful enough to handle the load of the car

Mechanical Controls Details

  • Steering
    • Custom 6061-T6 rack housing allows for low friction rack translation
    • 32x force magnification from steering wheel to steering rack
    • ~5° steering free play
    • 32° of steering
  • Brakes
    • Adjustable pedal position for better ergonomics
    • Manufactured with aluminum for decreased weight

Suspension Details

  • Short 65" wheelbase for lower polar moment of inertia
  • 52" track width reduces lateral weight transfer and increases lateral force produced by the tires when cornering
  • Steering rods aligned to have just 0.1° of steer for two inches of wheel displacement
  • Uprights and hubs CNC machined in-house.
  • Hubs designed to be interchangeable between left and right corners
  • Camber adjustable from 0° to -5.0° by use of threaded washers at the upper A arm point
  • Suspension designed to keep outside wheels at a 0° of camber under the maximum allowable body roll of 2° when cornering

Electrical Controls Details

  • Modular system of boards allows for easier development and replacement of controls system components
  • Electrical boards designed using EAGLE CAD, then manufactured on campus by team members using printed circuit board milling
  • Arduino software developed by team members and shared publicly as open source
  • Aluminum battery enclosure and front controls enclosure created using water-jet and in-house welding
  • Arduinos communicate with motor controller and battery management system entirely over CAN Bus network
  • Real-time data is read by the Arduinos and sent to a steering wheel display

High Voltage System Details

  • Emrax 207 Medium Voltage motor powers the drivetrain
  • Rinehart PM100DX Motor Controller controls the Emrax motor
  • Orion Battery Management System tracks cells
  • Single accumulator container holds all batteries and most high-voltage components
  • 4 team-packaged accumulator segments hold 82 LiFePo4 cells in series

2015

HyTech Racing at Formula Hybrid 2015

Vehicle Overview

CAD Design

Electrical Overview

2013

HyTech Racing's 2013 team is archived at this link.