System module

The system package collects all basic system functionality necessary to operate the car. This includes mainly basic diagnosis routines and the vehicle state machine.

Contact person: alexander.wischnewski@tum.de

Models

• mloc_diag_vehicle.slx collects several minor diagnosis functionality.

• mloc_statemachine.slx is the main state machine of the vehicle managing the startup, driving and emergency states.

• mvdc_performance_assessment.slx monitors performance related criterions of the controllers and the general driving behavior

Basic Setup

In the following, the basic tuning process is described for all algorithms in this component. Take care that some data dictionaries have vehicle specific version. This is always named e.g. db_xxxxxxxx.sldd. If you change a parameter, you have to do it in the vehicle specific version. This is configured before simulation or building the model automatically by the vehicle project.

Diagnosis ‘xx_mloc_diag_vehicle’

The diagnosis component provides a check, whether the vehicle is in a safe takeover condition. P_MLOC_SafeForTakeOver_FMax_N specifies the maximum allowed force request, this should be negative and approximately 10% of the maximum braking force. Furthermore, P_MLOC_SafeForTakeOver_vabsMax_mps gives the maximum admissable speed for takeover. These are checked during the startup sequence, therefore it is essential to calibrate it properly.

The vehicle unstable diagnostic can be activated via P_MLOC_ActivateVehicleUnstableDetection_b. It will check the side slip angle and compare it to the maximum safe value specified via P_MLOC_BetaMax_rad. If this is reached, an emergency brake is triggered.

State Machine

P_VDC_SoftEmergencyTimeout_s specifies the time until a hard emergency brake is performed after a non-critical failure was detected. This time should only be changed if you are aware of the consequences!

TUM Vehicle State:

Number	State	Description
0	OFF	System is off (no state)
10	STARTUP_Init	System startup started
11	STARTUP_WaitForSystem	Wait for CAN and hardware components
12	STARTUP_WaitForAIDriverComms	Wait for other AI driver components
20	IDLE_ActivateSensorFusion	Enable sensor fusion
21	IDLE_WaitForSensorFusion	Wait until sensor fusion is ok
22	IDLE_ActivateDriver	Enable trajectory driver
23	IDLE_WaitForDriver	Wait until trajectory driver is ok
24	IDLE_WaitForVehicle	Wait until vehicle is ready to drive
30	DRIVING	Normal driving
50	EMERGENCY	Soft emergency (uses emergency trajectory)
60	HARDEMERGENCY	Hit brakes and put steering straight

TUM Strategy Strategy:

Number	State	Description
0	S_OFF	System is off (no state)
10	S_STARTUP	Process started and initializing
20	S_IDLE	Standstill and waiting for vehicle controller
30	S_DRIVING	Normal driving
40	S_BRAKE2STOP	Mission finished and stopping the vehicle
50	S_EMERGENCY	Emergency situation detected

Error codes

The debug signal debug_ErrorCode (in the debug struct) holds a combined error code which encodes the most likely errors in a bitwise fashion. It is logged as a uint8 and therefore it is required to break the code into the bits manually (e.g. a value of 7 means that code 1, code 2 and code 4 are present). The error codes are:

Code	Description
001	Performance trajectory not ok
002	Emergency trajectory not ok
004	Path Deviation too high (below critical)
008	Path Deviation too high (above critical)
016	Trajectory Comms not ok
032	Strategy Comms not ok
064	Controller not ok
128	Trajectory too short for TMPC
256	Vehicle unstable
512	External module not ok