Requirement analysis of the ATP driver-machine interface simulation

The Vehicle Computer sent information to the ATP driver-machine interface at a
fixed frequency. The ATP translated the information to a readable data,
according to the prior agreed rules, and showed the data on the interface as
certain rules. The ATP followed multi-level hierarchical design ideas and was
decomposed into various views in its logic functions. Each view could be
divided into multiple sub-views and each sub-view was a further decomposition
of its parent view. Drivers may make driving operations based on the
information displayed in all levels of views, including entering data, such as
Driver ID, train number, train length and so on, controlling the train
independently for functions such as mitigation and change the running status,
and responding to the information sent by the vehicle security computer, such as
the need for confirmation of the driver when transforming from CTCS-2 to
CTCS-3. The information would be sent back to the Vehicle Computer by the
ATP after the driver finishes the operation and then responses were sent back to
the ATP after being confirmed by the Vehicle Computer, which formed a closed
loop for the information communication.
The train initial data, such as Driver ID, train number, train length and so on,
are input at the first step when the driver started to drive. Then the start button
was pressed. The driver should drive in accordance with the interface display.
During driving, the information transmitted from the Vehicle Computer was
responded to by the driver and the driver could control the train independently.

The main responding operations are confirmation of operation level and the
status of the front track.
From the workflow, the functions and use case of the system were confirmed,
including: 1. data display; 2. data input; 3. mode selection; 4. carrier frequency
mode selection; 5. selection and confirmation of operating level; 6. release
selection; 7. departure selection; 8. driver response. The ATP driver-machine
interface shows the information sent by the Vehicle Computer and contacts the
Vehicle Computer and the train driver. Therefore, it can be determined that the
driver and Vehicle Computer are system participants. The system use case
diagram is shown in Fig. 3.