Functional Description of EGM
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Status September 2003 (EvoBus-Service / AFT)
Page: 29 of 83
2.4.1
Throttle valve control
The throttle valve of the M 447 hLAG is positioned by an electric throttle valve actuator (DKS from
Woodward). The throttle valve actuator has its own integrated power and control electronics. The throttle
valve, electrical throttle valve actuator and the electronics form a unit. The throttle valve actuator is
supplied with power from the vehicle (not by the EGM). The actuator receives a target specification from
the EGM - the
throttle-valve target position
7
. The electronics integrated in the throttle valve carries out the
position control of the throttle valve and returns a position feedback to the EGM - the
throttle-valve actual
position
8
. This means the position control of the throttle valve is not carried out by the EGM, but instead
by the throttle valve actuator itself.
The target specification of the EGM is a PWM signal. The throttle valve actuator interprets the pulse duty
factor as the specification for the
throttle-valve target position
.
Throttle valve control: TV = f(throttle valve position)
7
Variable in Star diagnosis or on-board diagnosis (measured value 22)
8
Variable in Star diagnosis or on-board diagnosis (measured value 23)
DK - Pulse duty factor Woodward - throttle valve
TV [%] = f(target value)
TV
Target value
