CABRA OWNER’S MANUAL
7
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Steering
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The Cabra utilizes an electric over hydraulic power steering system. The
shaft from the steering wheel goes through an electric power steering gearbox which
boosts the input power of the driver turning the steering wheel. There is an electronic
control unit next to the steering gearbox which senses the input torque.
Care must be
taken when opening the dash panel to not disturb the signal wires which
could cause un-commanded turning while driving. Work behind the dash panel
should only be performed by UTD technicians or those trained on the Cabra.
The output shaft of the electric power steering gearbox turns a hydraulic pump which
then uses hydraulic fluid to actuate the hydraulic ram which turns the wheels. In the event
of a loss of electric power you will still have steering, but it will require much more effort
to steer.
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Brakes
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The Cabra utilizes regenerative braking. The position of the foot throttle
determines the speed the motor controllers are constantly working to achieve. The brake
pedal is not linked to this system. The regenerative braking is only determined by the
position of the foot throttle. For example, if the driver pushes the foot throttle to 50%,
the controllers will accelerate the vehicle to approximately 18 mph. If the driver then
releases the throttle to 0%, the controllers will command regenerative braking which
reverses the flow of electricity and charges the battery pack until the vehicle comes to a
stop on flat ground. (If going downhill it will not come to a complete stop without pressing
on the brake pedal.)
If the battery pack is fully charged and the vehicle
immediately goes down a steep hill, the battery management system (BMS) will
protect the battery pack from overcharging and will significantly reduce
regenerative braking. Running the Cabra in hybrid mode while the state of
charge (SOC) is above 80% will also reduce regenerative braking. Loss of
electrical power to the motor controllers will completely eliminate
regenerative braking.
With little or no regenerative braking, the force required on the
brake pedal is significantly more than a typical modern vehicle since it is a manual
hydraulic brake system without any power assist.
