×

Happy to Help!

This website doesn't store cookies. Enjoy the experience, without worrying about your data!

Great, thanks!

Motor Control Hardware and Software Development for an Electronic Power Steering (EPS) System

About the Customer

Our customer is a Europe based Tier-1 supplier of automotive steering and driveline solutions.

They were searching for an experienced Product Engineering partner for Proof-of-Concept (complete hardware and software solution) development, for one of their ambitious Electronic Power Steering (EPS) solution.

Business Challenge

There was a limited time frame for developing the complete hardware and software components of the electronic power steering and also validate it on the test-bench created by the OEM.

On top of that, the system was supposed to be ISO 26262 ASIL D compliant. This required expertise in creating safety plans and to follow the complete safety lifecycle as mandated by ISO 26262 standard.

Moreover, the need for integration with software stacks like J1939, was also felt to manage the communication with automotive ECU.

Since we had a ready-to-deploy J1939 stack solution, we were confident of adding value to this project by reducing the time-to-market

The customer also evaluated our expertise in motor controller development. By the virtue of our experience and skill-sets, we were on-board for this proof-of-concept development of EPS ECU.

However, the customer encountered a major roadblock during software porting.Due to limited on-chip memory (RAM and ROM) of DsPIC 30F4011 platform, it became imperative for the customer to port highly-optimized embedded software to the EPS system.

Re-designing or changing the hardware platform would have impacted the bottomline of the project negatively, leading to substantial financial loss. Also, the DsPIC Microchip platform was best suited for the required EPS application, meaning that the only feasible resolution was an Optimized Embedded Software.

Embitel’s Solution

After a few rounds of discussion with the customer’s automotive steering and driveline solutions team, it was decided that MPC5643L dual core micro controller will be best suited hardware platform for this project.

Our task was precisely cut-out, which was to develop the complete vehicle ECU hardware and software solution for the EPS.

The first step was to develop the hardware using this microcontroller. Following components were developed and integrated with the system:

The customer also evaluated our expertise in motor controller development. By the virtue of our experience and skill-sets, we were on-board for this proof-of-concept development of EPS ECU.

ASIL D certified MPC5643L dual core micro controller

2 KW NIDEC Motor (Automotive Grade)

ASIL D Pre-driver Component– Controls the motor with integrated PWM; Regulates HALL sensors etc.

Gate Driver IC- Acts as power amplifier for MOSFETS; Also sends error feedback to the ECU in a closed loop system

Voltage measurement sensor- Measures the motor voltage and passes the info to the ECU as a feedback

H-Bridge Component– MOSFETs

Steering Angle and Toque Sensor– Measures the angle and torque on the steering

HALL Sensor Feedback– To measure RPM, Motor Speed etc and send the data to the ECU

Temperature Sensors- Measures the temperature and feeds the reading to the ECU. This facilitates shutting down of the motor at high temperature

Our team also partnered to develop low-level drivers, hardware abstraction libraries and the application software required for the hardware platform and the peripherals.

We also designed various software algorithms in order to support necessary Motor Control features and functionalities.

Here’s the complete list of software algorithms that were developed

Algorithms
   Steering Control– Assist factor algorithm; torque sensors value, and angle sensor provided as inputs to the steering assist function, by external hardware. This algorithm also fetches RPM value via CAN message.
  Motor Control– It is an algorithm that sets the motor speed based on the torque. It also interfaces with steering assist functions.
  Signal conditioners– They smoothen the pulse value from the hardware. The sensors will provide ECG like values that need to be conditioned. This is called signal conditioning. The value is given to the motor controller after signal conditioning.
  Sensor Drivers– ADC drivers are required for reading the values from the sensors
  Actuator Drivers– PWM- used to adjust the motor speed; Gate driver unit drivers
  J1939 Based Bootloader and Diagnostics: Ready-to-deploy stack for ECU communication and vehicle diagnostics
  Standard Core- Memory handling, EEPROM, Scheduler

We tested the software and hardware using various testing tools. We also collaborated with the customer for End-of-Line Testing.

We tested all the software and hardware components on the test bench provided by the customer.

Some of the issues faced during this process and how they were rectified

The major problem that was faced in the test-bench was a jerk in the steer wheel. We were not able to get the desired smoothness.

Based on the parameters, we identified the issue in the assist factor algorithm. Our automotive developers were able to fine-tune the algorithm to adjust the assist factor.

“A safety lifecycle for hardware and software development was running in parallel to ensure that the components are ISO26262 ASIL D compliant. A safety manager was assigned for this and was supported by different teams.”

Embitel’s Impact

We were successful in developing the POC in 3 months- the time period that we were given by the customer. This helped the customer develop a PoC of an ISO 26262 ASIL D Electronic Power Steering ECU in a short period of time.

We were able to accomplish the task due to the following reasons:

Our power steering system and software capabilities

Ready-to use Bootloader J1939 for diagnostics

Team of Motor Control Experts

Tools and Technologies Used

IDE- CodeWarrior

Vehicle Spy for CAN Signal Simulation

CANOe Analyser

Contact Us

© 2018 Embitel. All Rights Reserved