Page 38 - Mechatronics with Experiments

JWST499-Cetinkunt
JWST499-c01
24 MECHATRONICS Printer: Yet to Come October 9, 2014 7:39 254mm×178mm
Engine side
Engine harness
ECM
4-16 OEM harness
Hydraulic
electronic
unit
injectors Vehicle side
Ground –
*Rail pressure Cruise stud 12/24 V
control valve on, set, & +
*Speed/timing resume ECAP
sensor switches
J1587
Coolant temp Service data
sensor
& parking link
Fuel temp brake switches
sensor
Clutch
*Oiltemp switch Electronic dash
sensor
Inlet air Jake brake
temp sensor switches J1922 powertrain
Inlet manifold data link
pres sensor
Coolant
Atmospherlc level switch Throttle Pedal
pres sensor sensor
Oil pressure
sensor Vehicle
Engine speed sensor
Fuel pressure brake
sensor Diagnostic & warning
*Rail pressure * Required for HEUI operation lamps
sensor
FIGURE 1.21: Control system components for a modern engine controller: sensor inputs,
ECM (electronic control module), outputs to actuators. Reprinted Courtesy of Caterpillar Inc.
6. atmospheric pressure sensor,
7. manifold temperature sensor,
8. ambient air temperature sensor,
9. exhaust gas oxygen (EGO) sensor,
10. knock detector sensor (piezo-accelerometer sensor)
The controlled actuators in an engine (outputs) are:
1. fuel injector actuation: injection timing, duration (injected fuel amount, also called
fuel ratio) and pulse shape control,
2. ignition sparks: timing (only in spark-ignited gasoline engines, not used in diesel
engines),
3. exhaust gas recirculation (EGR) valve,
4. idle air control (IAC) valve, which may not be present in all engine designs,
5. waste-gate valve,
6. exhaust back pressure valve, and
7. turbo charger.

ECM is the digital computer hardware which has the interface circuitry for the sensors
and actuators and runs the engine control algorithm (engine control software) in real-time.
The engine control algorithm implements the control logic that defines the relationship
between the sensor signals and actuator control signals. The main objectives of engine
control are
1. engine speed control,
2. fuel efficiency, and
3. emission concerns.