Student Projects
Contact Information
Country: Brazil
Year Submitted: 2018
University: FATEC Santo ANDRE
List of Team Members (with year of graduation):
Homero de Oliveira, year of graduation, 2017
Faculty Advisers:
Prof. Dr. Edson Caoru Kitani
Main Contact Email Address: Edson.kitani@fatec.sp.gov.br
Project Information
Title: Hardware in the Loop for Testing Automotive Alternators Dynamically
Description:
The project aim to develop an equipment to test automotive alternators dynamically, creating similar conditions as we have in the passenger cars. In this situation, it is possible to collect more accurate data about the electrical and mechanical conditions of the alternators.
The equipment is composed by a three-phase induction motor, frequency inverter, 1.2kW electronic load, automotive battery and data acquisition system based on DAQ USB 6009 and LabView 2016. All those parts are mounted in a workbench that can accept different sizes of alternators.
Using the DAQ USB 6009 we can generate an analog signal (0-10V) to control the frequency inverter and then control the speed of induction motor and control the 1.2kW electronic load using analog input (0-10V) also. Both systems simulate speed and load. The profile of the electrical load and speed is recorded using a real vehicle and then reproduced in the HIL workbench.
Products:
The main products used from NI was: DAQ USB 6009 and LabView 2016.
The Challenge:
The initial challenge was to develop a safe equipment to test automotive alternators with capability to impose the same speed / load conditions found in the real engine vehicle. In this way, it is possible to perform several tests simulating the real situation of vehicle engine, however without exposing the user or operator in unsafe conditions.
Integrate hardware and software was not an easy task in this project. The first idea was to use a microcontroller PIC 18F4550 and discrete analog hardware. During the initial discussion with the team it was realized the solution could take a long time and not accomplish a reasonable result. Although, the unique nonstandard hardware designed and built was the 1,2kW electronic load.
The Solution:
The solution was to implement the control platform using a standard software that provide a full integration between hardware and software. The natural choice was to create the framework using LabView and the hardware DAQ USB 6009. Comparing all requirements (hardware and software) necessary by microcontroller and LabView showed us the advantage of the second option.
Basically, the LabView VI software controls the frequency of the inverter using a linear scale (0 to 10V for 0 to 60Hz) simulating the speed variation and another analog output to control and simulate the load consumption. Controlling that two variables (speed and electrical load) we impose different profiles of working over the alternator and evaluate the electrical and mechanical responses. The operator can read the test values on the front panel and have a log file at the end of tests. Additionally, the system has a speed feedback to keep the rotation of the motor constant. Though, varying the intensity of the load it is possible to get the alternator performance curve for each speed.
The operator can work in two ways: manually or automatically. In manual mode, there are knobs and switches to control speed and electrical load consumption. In manual mode is possible to perform adjustments and some repairs. In automatic mode, the program reads a file with a test script, using spreadsheet file format and divided in three variable columns: speed, current load and duration in second. On each line, we can write a test condition and duration providing a quite flexible system to test and evaluate the performance of alternator.
One of the main benefits of using NI platform is the easy and full integration between software and hardware. We did not have problems with software driven system or incompatibility, missing drivers, etc. No adjustments were required.
Another benefit was how fast we could prototype and test the software and hardware integration with our workbench. No compilation process neither flashing memories were necessary. Additionally, the design of professional front panel in an intuitive and easy form was the greater benefit.
Finally, during the development of the project, LabView allowed us to focus on the solution of our design and not over the coding or software details and compilation errors. The vast amount of library functions speed up the design too.
The figure below shows a general overview of our implementation. We took a commercial alternator test workbench and automated it in order achieve capabilities that was not thought before.
Figure 1: - General overview of HIL of Automotive Alternator Workbench
The next figure represents a simplified framework of our solution.
Status of the Project
The design was part of Graduation Thesis and presented at the end of 2017 to the Examiners at FATEC Santo Andre. On that perspective, we consider the project finished.
Time to Built
The time to develop and built was eight (8) months, because the workbench is a commercial product without any automation. We implemented all controls and resources such as the 1,2kW electronic load, frequency inverter, etc.
Additional revisions
As a suggestion to enhance the design and performance we can mention:
- Enhance the speed control, implementing the PID strategy;
- Install a thermal control device to generate heat or cooling in order to simulate the thermal variations;
- Optimize the datalogging and data analysis.
Link to Video
