Updated: 1 August 2012
Extensive simulation has been completed. A realistic model for an engine, hydraulic unit and accumulator has been developed that will be used for generic vehicle studies. This phase was developed to determine the performance of a Miser equipped vehicle against a conventional vehicle. This study has shown and still continues to predict a realistic percent saving that the Miser can do compared to a conventional vehicle. The two areas that are key outputs are a) to see how much of the theoretical regenerative braking a Miser can recover including all inefficiencies. This will be used to determine optimum accumulator and pump sizes for future designs, and b) the other aspect that must be shown is the fuel saving resulting from being able to optimize the engine relative to a conventional transmission. Continuing on from this, the model has been and is continually being expanded to a) other vehicle sizes and b) specific types of drive (eg. max acceleration). Ongoing enhancements include minor improvements relating to the efficiencies of the gears, etc. This is the major direction at this time. The simulation will be an ongoing activity.
The control system is also dependant on some results from the simulation and is still awaiting some of those outputs before it can be completed. However, the basic hardware and interfaces to the computer have been shown to work. Having mounted the control system in the vehicle and having driven it in “speed summing mode”, proved to be encouraging and great fun! Now we continue to develop each of the other modes based on the simulation work. The major work in this area is to determine which mode to use at various times and how to transition between modes. It has been seen that the transition between each mode will require advanced control systems and will require significant work. The control system is being developed to include a data logging ability. Once the control system is developed to completion, the system must be transferred from Labview to a conventional microchip type control system. Currently, it is an ongoing process.
Universal Gearbox Design
The Miser type gearbox is mechanically quite simple and comparatively small, so a single design can be extended across a wide range of vehicles. This means that it does not require a wide range of sizes to cover many vehicle sizes. The basic mechanical layout of a universal gearbox has been developed that could be used in vehicles up to the size of a Jeep / Land Rover. This concept must be confirmed by detailed design and sizing using design standards and commercial software. There are aspects of the design such as the twin planet gear system that will require external contracting for the detailed design. The concept is that this gearbox will be mounted virtually in any direction (front, right, left, etc, inputs on front or back end). The areas that still require significant work are the selection of the clutches and the hydraulic pump. These will be based on industry standard type components for the initial designs. The basic design then needs to be used to develop a similar design for mid range truck type vehicles and another version for large trucks and earth movers.
This vehicle was developed using available components and is therefore not optimized. It was used as a pure test bench only and every component will eventually be replaced by a production version. We drove this vehicle periodically over a period of nine months to prove that our technology works…it performed above expectation! Very exciting! Our next step is to complete a vehicle specific production Miser…this is in the pipeline.