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ILDP

Stage 1: 8x8 and a Trailer

ILDP was the proof of concept stage where a prototype system could be presented, tested and evaluated. Based on the success of this stage, DND would make a decision whether or not to continue on with the production stage, ILDS.

It was also the stage where they players were picked and prepared for ILDS. The people at DRES, basically with all of the technical know how, were the project managers for ILDP. Their role was two fold: develop the system into a working product and develop the team of contractors to deliver and support the production systems if ILDS went ahead. GDC was selected as the prime system integrator - a role like a general contractor. They would to be responsible for ILDS. A handful of other companies including Qsine were selected by DRES for their technical expertise in specific areas. It would be up to us to make our contributions via GDC for ILDS.

ILDP progressed with DRES's people calling the shots and, for the most part, GDC's people rode shotgun. While everyone understood that they would take the reigns in ILDS, it split the hierarchy and made for some strange relationship building. We were selected by DRES to design and build the vehicle but there was also a complex trailer that carried and positioned the TNA sensor. For some reason GDC was given the task of delivering the trailer and they were instructed by DRES to contract Qsine to design and build it.

GDC's people had never worked with us before and I think they were a bit put out being told who they had to work with. I remember our first meeting thinking "These guys think we are going to stick it to them!" Of course we had no intention of doing that. With DRES having the faith to give us authority on the trailer, we were not about to tarnish their reputation by abusing the power given to us.

The vehicle that the VCG proposed for the project was a scaled up version of the ARGO demonstration vehicle. It was an 8x8, skid steered vehicle with bogie suspension as seen here with the trailer in tow.

DRES is not actually military; it is a civilian organization doing military research. As such, ILDP being a DRES experimental project, as opposed to a DND project, the documentation requirements were relatively light and the time frame compressed. It was about a year from the time things got started to when the vehicle was delivered. We worked along side the people at DRES throughout the project. In fact, when the vehicle assembly started, Chris Brosinsky, Rob Ellingson and Steve Penzies came to Qsine to help out and get an early start on installing controls and accessories from some of the other systems.

The VCG guys at DRES set vehicle's basic specifications. They wanted:

  • An 8 wheel, all-wheel drive configuration to keep the weight distributed and ground pressure light.
  • A quad bogie suspension to maintain wheel contact with the terrain.
  • To use differential wheel speed for steering (basically skid steering) as it would allow the vehicle to pan (turn on the spot) if required.
  • Diesel power
  • A top speed of 10 km/hr
  • 100% gradability
There were other specifications for ingress and egress angles etc. but the above specifications are really what was important to the project. We used a small Kubota 4 cylinder diesel engine and coupled it to a 46 Series, Sundtrand, closed loop hydraulic pump. Each wheel was driven with a Black Bruin radial piston motor. These motors where dual displacement, which made the transmission act like a 2 speed transmission (i.e. high/low configuration). The other interesting thing we did was make the trransmission act like a four speed gear box. Typical to radial piston motor's, the Black Bruin's could be set to free-wheel mode by floating the pistons off of the cam rings. We integrated controls right into the bogie pivots so the motors could be set to free-wheel mode in left/right pairs. With all motors working, we had a maximum torque/minimum speed configuration. With all but one pair of motors kicked out, we had a minimum torque/maximum speed configuration. Besides having the controls integrated into the pivots, we also made the bogie arms as hydraulic manifolds so there was no external plumbing. Unfortunantly, we never took very good photos of this so I can't show them.

Basically, the four modes create discrete torque/speed ranges to work within but the variable displacement pump gave continuous speed control in each mode, from zero to full speed. The advantage of the hydrostatic transmission is that it can attain infinite ratio. In other words, the engine can spin at full RPM while the vehicle is stationary. There is no need for a clutch. In fact, with the pump at zero displacement, the vehicle is held at zero speed. So unlike an automatic transmission with a torque converter, the hydrostatic drive will not coast down a hill. Over time it will creep on a hill so a brake is required when the vehicle is parked but for operatonal stops, friction brakes are unecessary.

The major problem with this vehicle was that it could not keep all of it's wheel firmly on the ground. The four bogie pivots can be imagine like legs on a table: on uneven ground only three touch at one time and the fourth is always floating in the air as the balance changes. While the bogies kept all of the wheels on the ground with the Argo, we realized it was only because the chassis was flimsy enough to act like a suspension. Our vehicle was designed with a very rigid chassis to hold the sensors firm so that their positions would be predicatable as the vehicle experienced pitch and roll from the ground conditions.

This is the major reason why the vehicle changed from ILDP to ILDS. The trailer turned out to be quite cumbersome and designed out of ILDS also.