ECU Master TUNER3 Manuel de service télécharger pdf (Page 22)

Boost control

Using DET3 in Fuel Implant mode gives the possibility of controlling the boost pressure both in open loop and

closed loop. In order to be able to use the boost control all injectors have to be connected into the first power

output (pin 20 of the device, work in full group mode).

Open Loop

Controlling the boost pressure in Open Loop mode is

based only on duty cycle of PWM signal controlling the

electric valve. Because of that depending on the

conditions (i.e. temperature, engines strain) boost

pressure may vary. In order to eliminate this problem

Closed Loop control should be applied (with feedback).

However the first step is the creation of a 2D table of

base duty cycle at given RPM in order to receive

approximate values of the desired boost (menu Boost

control / Boost DC Table). Values on this table vary from

0% (valve not energized) to 100% (valve fully

energized). It is worth noting, that due to the way electric

valves work the typical usable range of signal’s duty cycle is from 15% to 85% .

Closed Loop

At the time when the boost is set with DC Table corresponds the expected boost values, one can move to

defining the boost map (in kpa) in the RPM function (Boost control / Boost target table). In this table, we present

the desired boost which the controller will try to achieve independently from the engines work conditions. The

controller modifies, based on the PID algorithm, the duty cycle of the electro valve, defined in Boost DC Table.

Correct defining of the PID parameters allows acquiring stable boost pressure without oscillation. First the value

of the P (proportional) parameter has to be set (I and D should be set to 0), so that the controller will closing on

the desired boost target with small oscillation. Those oscillations can be eliminated with correctly set values of

the I (integral) and D (derivative) parameters.

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ECU Master TUNER3 Manuel de service Page 22