Senior Project – Electrical Engineering – 2009

THE WINGMAN: SELF-SPOTTING BENCH PRESSChris Potts (EE) & Lane Caffaro (ME)

Advisors: John Spinelli (EE) & Jennifer Currey (ME)

ABSTRACT: In modern day society, health and fitness have become the focus of many Americans. As a result, working out and weight lifting plays a large role in many people’s lives. In order to obtain more strength, one must maximize his/her potential muscle growth. The ideal way to do this is by working the muscles until failure. This can be extremely hazardous on the bench press machine without a human spotter there to provide aid if the circumstances require it. The Wingman allows weight lifters to work their muscles until he/she doubts him/herself capable of lifting the barbell. A human spotter will become obsolete, and the lifter will still be able to augment his/her muscle capacity with safety as a priority. The Wingman, there to take the fall so you can be the strongest of them all.

FUTURE Work: - Wireless- Regulator for Amount of Weight- Sensors for Horizontal Movement- Ready Beep/System Failure Alarm- Attachment of Distance Sensors on Barbell- Adjustable Range of Motion by Pneumatic Cylinders

DESIGN GOALS: First, the system must meet the definition of a free weight workout machine. This means that the barbell must not have any constraints on its directional motion and there must be no outside contact with the barbell aside from the weight plates and the lifter’s grip. Also, the lifter must be able to comfortably grip the barbell, so any switches for manual activation must be unobtrusive. Second, the system must act as a spotter and provide assistance to the lifter only when it is necessary. Therefore, the system must be able to recognize when the lifter can no longer lift the barbell, whether it be from manual activation by the lifter or automatic activation by the system. Third, the system must be able to lift the barbell and weight vertically away from the lifter in a relatively quick manner. Finally, it would also be advantageous for the design to include an output device that can display the total time and the number of repetitions for each set.

CIRCUIT DIAGRAMS: Micro/Ribbon Switches: Solenoid Interface:

SYSTEM DESIGN:

FLOW CHART:

BLOCK DIAGRAM:

NOTE: For mechanical details, please see Lane Caffaro’s poster in the ME wing.

EVALUATION: The microcontroller was able to properly communicate with all the switches, sensors, and solenoid in order to raise/lower the air pressurized pneumatic cylinders only when the lifter needed assistance. The micro switches correctly activated the system by energizing the solenoid and deactivated the system once the barbell was racked. The ribbon switches worked as a manual trigger so as to deenergize the solenoid when lifter released his/her grip. The distance sensors automatically deenergized solenoid, regardless of ribbon switch operation, if the barbell was uneven by 6 or more inches or if barbell was stationary for 2 or more seconds. Lastly, the LCD accurately displayed the total time and the number of repetitions for each set. Therefore, the Wingman is a true free weight system and a safe alternative to lifting without a human spotter.