NSF-Funded Student Design Projects:
Parts Dispensing and Counting System

Designers: David Sant, Vijay Gummadi
Client Coordinator: Ronald Zapinski
Keith Bovenschen School
Supervising Professor: Robert Erlandson, Ph.D.
Department of Electrical and Computer Engineering
Wayne State University, Detroit, MI 48202

INTRODUCTION

Keith Bovenschen School in Warren, Michigan serves students between the ages of 3 and 26 who have various types of disabilities. As a means of keeping the students active in the community and promoting positive work skills, Bovenschen staff engage the students in a variety of counting and sorting tasks. The school has contracts with local businesses to package items by count or by weight. Many Bovenschen students, however, have limited finger dexterity and cannot count reliably without assistance. The modular Parts Dispensing and Counting System combines sensor technology with existing assistive technology devices to help students with disabilities accurately count and sort small materials.

SUMMARY OF IMPACT

Students with severe mental and physical impairments are often unable to participate in vocational tasks due to their impairments. The Parts Dispensing and Counting System allows students to start the task by simply hitting a switch. When switches are used to compensate for physical or mental performance, a larger population of students can participate. Furthermore, it was found that the noise of the materials rotating in the dispensing bin aids in holding the students’ attention, and, because the process is begun by hitting a hitting a single switch, this project provides a means for these students to understand cause-and-effect relationships.

TECHNICAL DESCRIPTION

The system setup consists of a coffee can mounted on roller bearings that is powered by a motor to rotate at approximately 30 RPM. The can’s lid has four holes for the parts to fall through located at diametrically opposite ends, and a funnel located at the base of the apparatus collects and routes the parts as they are dispensed into a collection bin (see figure 1).
 
 

At the bottom of the funnel are infrared sensors that detect each part as it passes through the funnel. An ETL Counter Controller, which can be programmed to count a specific number of parts, keeps track of the number of parts passed by the infrared sensor. When the session’s counting goal has been reached, the process halts, allowing staff or other students to replace the current collection bin with another. To start the process again, the user hits the switch connected to the ETL Counter Controller.

The system can also be interfaced to an ETL Indexing Turntable for increased functionality. By incorporating the turntable, staff may set collection bins at up to eight indexed stop points on the turntable. When one session goal has been reached, the turntable advances to the next indexed position, and, after the switch is hit again, the system will begin to dispense material into the new collection box (see figure 2).
 
 

By allowing the system to handle both the material handling and counting procedures, the cognitive and physical demands of the task are reduced, allowing individuals with increasingly sophisticated types of disabilities to participate. The system costs approximately $400 without the turntable and $1000 with the turntable.