Design team members: Wahini Ambihapathy, Trecia Brown
Supervisor: Professor Fakhri Karray
Background
Current models of vehicles are equipped with various safety devices in an effort to minimize the risk of injury to occupants in the event of a collision. These devices include seatbelts and airbags. Seatbelts are designed to restrain the body and restrict the forward motion of the body in a collision. Airbags are the second level of protection in that they supplement the usage of the seatbelts by cushioning the body during forward motion. Current airbag systems have been designed to deploy against the chest of the occupant since this has been found to be the sturdiest part of the upper body and thus minimize internal injury caused by the extensive force applied by the airbag. This, unfortunately, is a problem because the design of airbags has not taken variations in anthropometric data into consideration. Consequently, small-statured adults and children are at greater risk of injury caused by the airbag deployment as opposed to that caused by the collision. Since airbags have been credited with saving thousands of lives, a need has arisen to maximize these life-saving properties while minimizing the risk of injury.
Project description
The purpose of this project is to create an airbag system that will imitate the behaviour of a human operator where the decision-making process will incorporate numerous factors. Some of these factors are:
- Use of seatbelts during the collision
- Anthropometric measurements of both passenger and driver
- Presence/absence of child seats
- Speed and position of impact
The objectives of this workshop project are to produce an intelligent airbag system that will
- minimize the number of airbag-related injuries
- provide for different levels of airbag deployment
- allow for integration in any vehicle
- -minimize costs due to inappropriate activation of the airbag
Design methodology
Criteria
- Ease of implementation: The solution should be as simple as possible to facilitate its implementation both in hardware and software. This will also ensure that it is an attractive solution to automobile manufacturers.
- Minimal change to existing vehicle design: The solution should be easily integrated into existing vehicle models without requiring significant refitting.
- Superiority to existing solutions: The new design should try to succeed where the other solutions have failed. It should be an improvement on existing solutions and should fulfil the outlined objectives.
Constraints
- Costs: The solution should minimize overall costs.
- Existing regulations: The solution should comply with current federal guidelines.
- Weight: The solution should not add an excessive amount of weight to the vehicle.
Proposed design
The current proposed design takes existing airbag systems and adds intelligence to the model. The intelligence that has been proposed is a fuzzy logic inference engine. A fuzzy logic engine was chosen due to the ill-defined system of inputs. It allows for an if/then rules set and logic processing required for the choice of the activation state. The final intelligent system will be based on a large number of inputs, but the solution that this project will look at will only consider 5 inputs. The inputs were limited to 5 variables to control the scope of the project and to limit the size of the inference engine and its rules.