ECU Software Validation using Hardware-In-Loop Test Setup Automation Shrirang Agashe Eaton Technologies Pvt. Ltd. EON Free Zone, Cluster C, Wing 1, MIDC, Kharadi, Pune 411014 20-Oct-12
Need for Hardware In Loop Test Setup VALIDATION To demonstrate that the product fulfills its intended use when placed in its intended environment. Need For ECU S/W VALIDATION (In Vehicle Testing): 1. Increase Software Reliability (Safety) 2. Decrease Warranty Claims HIL System plays key Role in Software VALIDATION. The key benefits are: 1. Expedite VALIDATION Process 2. Reduce In Vehicle testing Resources (Test Tracks, Vehicles, Man Power) 3. Regression Testing for Different Software Versions HIL System Provides the Simulated / Virtual Intended Environment for VALIDATION of S/W in ECU Under Test 2 2
HIL System Components 1. ECU Under Test: Holds S/W To Be Tested 2. Power Supplies: Provides VBATT & GND to all electrical components 3. Real Time Computer: Simulation of ECU Environment (Plant Models) 4. Signal Generation & Measurement Cards: Electrical Interface 5. ECU Harness: Electrical Connections 6. Communication Cards: Simulate the messaging with other ECUs 7. Simulated Loads: Current Sink 8. Fault Insertion Unit: Electrical Diagnostics 9. Host PC: Operator / Environment Inputs, Static linking between RTPC, I / O Cards, Communication Cards 3 3
H I L S y s t e m I l l u s t r a t i o n 1 : W i n d s h i e l d Wiper Requirement: The wiper should turn on when wiper switch is pressed. Also wiper should turn off when wiper switch is pressed and wiper has reached its parking position. Controller Environment Intermediate Position Input Input Wiper Switch Input Wiper Motor Wiper Motor Limit switch Plant Model Parking Position Wiper Parking position Limit Switch 4 4
HIL System Illustration 1: Windshield Wiper Continued Controller Wiper Motor Electrical PWM / ADC In Card Input RTPC (Simulated Plant) Intermediate Position Wiper S/W Electrical Input Parking S/W Electrical Input Parking Position Digital Out Card Wiper Parking position Limit Switch Host PC GUI Wiper Switch Ethernet Link RTPC Wiper Switch 5 5
HIL System Illustration 2: Transmission Control Module (Auto Transmission) HIL System Fault Insertion Unit Electrical Diagnostics Signal Measurement Cards Plant Model 1. Engine 2. Transmission Dynamics 3. Driveline l Generation Cards Signal Electrical Loads Speed Sensors TCM 4. Brakes Actuators: Information of Commanded Gear Electrical Loads Host PC: 1. Driver Demand 2. Road Characteristics 6 6
Plant Model Design 1. Layout of Model: Input Interface, Plant Model, Interface. Overrides for functional diagnostics. 2. CAN message Interface: Compatibility between MIL and HIL Models 3. Modular Components: Reusability of standard components 4. Configuration Parameters: Managing different variants 5. Modeling Conventions / Guidelines: Common understanding and maintenance 7 7
HIL Setup Automation And Benefits Automation Framework should include: 1. Execution (20%) a. Open Loop and Closed Loop b. Variables to be logged: logging rate c. Safe exit in case of error d. Library Functions for common execution scenario / fault injections 2. Data Analysis (80%) a. Reading the data log files b. Pass / Fail Criteria Benefits of HIL Automation: 1. In Vehicle testing time a. Availability of the test tracks: In lab testing can be done 24 hours b. Time for making the connections for data logging, communication 2. Repeatability in the execution. Test scenario execution is driver independent. 3. Regression Testing: Intermediate releases of software can also be tested. 4. Test Coverage: Same software can be tested on all the variants of the vehicle 5. For diagnostic testing, the FIU can inject the faults with 10 ms timing accuracy. This is impossible in actual vehicle. 6. Exhaustive data capturing, recording and reporting. 7. Consistency in the pass / fail criteria: It is not open to discretion of any person s engineering decision. 8 8