Special Functions; Not Can Bus Assisted Application; Acquiring The Motor Resistance; Alignment At The Rest Position - Zapi EPS-AC0 SWs&ENC User Manual

12 SPECIAL FUNCTIONS

Here is a list of special functions hand set assisted, that are not documented yet.

12.1 Not CAN Bus assisted application

Eps_ac0 may work in a stand alone configuration (not CAN Bus assisted). Two
operations are required in this case:
1) Set CAN BUS in the hardware setting menu to ABSENT (see 11.4.5.2) and
recycle the key.
2) Connect a travel demand input to CNA#1 (and a battery positive). It could be a
tiller switch (see connecting diagrams 5.2-5.3). This information is used to turn
the steering controller from stand-by to operational mode depending by the state
of this CNA#1 input.
Without connecting CNA#1 to a travel demand, the steering controller exits the
stand-by mode only for a large jerk of the tiller position.
Obviously we pay duty on working without CAN Bus:
1) It is not possible to change the sensitivity of the steer with the truck speed.
2) It is not possible to reduce the truck speed when the steered wheel angle
increases.

12.2 Acquiring the Motor resistance

When it is possible, the steering motor is controlled sensorless. To get the best
performance in terms of the max torque generated, it is necessary to compensate
for the drop in the motor resistance. So the correct value of the motor resistance
must be known.
Eps-ac0 provides a self-acquisition procedure to acquire the motor resistance.
It is just enough to connect the eps-ac0 to the battery, to the motor and to the wiring
in order no alarm occurs. Then:
1) Enter the ADJUSTMENTS menu searching for ADJUSTMENT #01 setting.
2) Turn ADJUSTMENT #01 to Level 1. (A DATA ACQUISITION alarm occurs and
a half Imax DC current is automatically injected in the motor).
3) Wait about 2 secs.
4) Roll ADJUSTMENT #01 back to Level 0.
5) Save the new setting.
With this procedure the resistance between two motor terminals is automatically
measured and recorded (in milliohms) on the ADJUSTMENT #02 (see 11.4.2.3).
It is also possible to adjust the motor resistance value without self-acquisition by
rolling the ADJUSTMENT #02.
The acquisition of the motor resistance should be performed to find the correct value
when developing a new truck prototype; the correct value will be the default setting
for the mass production of that truck.

12.3 Alignment at the rest position

In the open loop applications (i.e. when the stepper motor is used in the steering
wheel or the steer command is a speed information coming via CAN bus) an
alignment at the rest position is automatically performed when the steered wheel
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