Group 1

1.1. Context Diagram
a. {pressBrake, releaseBrake}
b. {pressAccel, releaseAccel}
c. {sendBrakeSignal}
d. {sendIincreaseSpeedSignal}
e. {engineControlUsingBowdenWire}
1.2. Shortcomings
f. {brakeControlUsingBowdenWire}
g. {increaseSpeed, decreaseSpeed}
h. {sendBrakeSignal}
i. {controlBrake, brakeStatusSignal}
SC1: Engine cannot automatically stop (decreaseSpeed immediately) when it is very
close to another car ahead of it.
SC2: Engine cannot increaseSpeed automatically with the desired speed or default
speed when there is distance big enough ahead of it after braking.
SC3: The system can not measure the distance to an object in front of the car.
SC4: The Driver must drive fully concentrate to preserve the desired speed and safe.
1.3. Facts
F1: The standard car is equipped with an anti-lock braking system (ABS) that has
an additional digital input to activate the Brakes. The ABS digital input is
realized by a serial (RS-232) connection with 9600 Baud, odd parity, and one
stop bit. Values between “0” and “255” readMsgforBrake. When Driver
pressBrake and then BrakePedal send brakeSignal “255” to the ABS, the car
brakes as strongly as possible. Otherwise when Driver releaseBrake,
furthermore send brakeSignal “0” will send to the ABS, and the Brakes are
released completely.
F2: Controller-area network (CAN or CAN-Bus) is a vehicle bus standard designed
to allow microcontrollers and devices to communicate with each other within a
vehicle without a host computer
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