POSITION COMMUNICATION SYSTEM
Sponsored by:
NATIONAL COLLEGIATE INVENTORS AND INOVATORS ALLIANCE (NCIIA)
SUBMITTED TO:
Department of Mechanical Engineering
University of Idaho
SUBMITTED BY:
Full Load E-Team
Ian Toevs
Matt Shewmaker
Veronica Meyer
Seth Elkington
Matt Hess
Chris Jenson
December 16, 2003
INTRODUCTION
During the original Full Load E-Team design review, it was called to the attention that some major design issues had not been addressed. These issues include: a product definition that will guarantee market success and delight the users, a conceptual design that communicates all features intended in the product and that can be purchased at reasonable costs, and a prototype or prototype elements along with experimentation activities demonstrating implementation feasibility.
After this was established, the E-Team decided to redefine and reevaluate the problems, which are as follows: the truck drivers cannot see to guide themselves while loading, and it is difficult for the harvester operator to provide input for additional tasks. From this, the team decided that the system needed to be as automated as possible and then developed alternative design concepts.
ALTERNATE CONCEPTS
Other ideas proposed for automating the signals communicated by the PCSys are shown in Table 1.
Table 1: Alternate Design Concepts
Item / Use / Advantages / DisadvantageUltrasonic sensors / Maintain lateral positioning between truck and harvester / Accurate Distance measurement between objects / Expensive, interference issues, extensive installation
Photo-gates / Determine load level in truck bed / Automatically resets / Expensive, interference issues, extensive installation
Laser sensors / Load level and lateral position / Accurate Distance measurement between objects / Expensive, interference issues, extensive installation
Load cells / Load level and lateral position / Provide weights of each truck load / Expensive, extensive installation
Radar sensors / maintain lateral position / Accurate velocity measurement between objects / Interference issues, extensive installation
Table 1 allowed us to compare the different concepts by compare their advantages and disadvantages. From this table and additional research, the pool of ideas was narrowed down to ultrasonic sensors combined with a radar velocity sensor. However, it appears as though using these ideas will be more expensive and harder to implement than using the proposed wireless video camera/monitor set paired with radio communication.
PRODUCT DEFINITION
This product will:
• Provide position information to the truck driver(s) relative to the position of the harvester.
• Ensure that the truck is positioned for proper loading.
• Be competitive in cost and function with existing technology.
• Eliminate unneeded workload for the harvester operator.
The final outcome will be to form a corporation which will manage the manufactured product to be sold to the mass market.
DESIGN CONCEPT
In light of recent feedback from several individuals, The Full Load E-Team has drastically changed the design concept of the Position Communication System (PCSys). The team will move toward a design that will require less input responsibility from the harvester operator and place the majority of position adjustment responsibilities in the hands of the truck operator. In theory this idea shows promise; however, the implementation of the concept could prove to be very challenging.
The current design involves the harvester operator continually transmitting position adjustments to the receiver in the truck cab. The new design will utilize a small wireless camera with a view of the truck bed. The camera image will be sent to a monitor in the cab of the truck from which the truck operator can make position adjustments. Locations being considered for mounting the camera are shown in Figure 1.
Figure 1: Possible Camera Locations on Harvester & Truck
These four camera locations shown in Figure 1 were chosen based on our testing North of Pullman, WA on December 6, 2003. This picture is a typical situation for the potato harvest and accurately shows the positioning of the harvester and truck relative to each other. For each location, a short description can be seen below:
- Above the harvester in line with the boom, looking down on the truck bed
- At the rear corner of the harvester closest to the truck.
- Placing a camera at a front and back corner of the truck bed
- Above the cab of the tractor
Camera mounting can be customized based on the customers’ best interests.
Receiving the camera’s transmission is a monitor located in the truck cab. This monitor would display exactly what the camera’s view is so that position adjustments can be made. Due to space restrictions in the cab, a simple T.V. tube monitor will not be as feasible as some kind of flat screen. An LCD display that could be mounted in the same line of sight as the driver’s side rear view mirror would be ideal.
Although the camera and monitor will significantly reduce the need for the harvester operator to make position change inputs, the E-team still believes that it is important for the truck and harvester operators to have a clear medium of communication. For this reason, a C.B. or 2-way radio will be included in the design. Optimally, the E-team would like to see that the communication between the operators be hands free, so some type of head set or ear piece will be used. Figure 2 displays the integration of the wireless video and radio system.
Figure 2: Block Diagram for the New Design Concept
This block diagram shows the wireless transmission of the camera to the monitor located in the truck cab. It also demonstrates the radio communication between both the harvester and truck operators.
DESIGN EVALUATION
When considering the feasibility of the new product design, the E-Team developed a compilation of possible problems that will most likely be encountered. Weather effects account for many of the potential problems that could occur. The sheer nature of farming produces clouds of dust which will inevitably settle on the camera lens and monitor screen. Some method of prevention such as self-cleaning films used in off-road racing or shields could be utilized to minimize the problem, since it could be troublesome at times for the operators to manually clean the lens of the camera. The monitor however, shouldn’t be as exposed to the dust and could be easily cleaned with a cloth. In addition to this, moisture on or in the camera could prohibit clear video feed to the monitor.
The second main issue is mounting the camera and monitors so that shock and overall wear on the units will be minimized. These mounts will also be required to be easy to install at the beginning of harvest and remove once harvest season is over. Also, the monitor could be stowed in the truck cab during the off season. Generally, the PCSys needs to be reliable, durable, and easy for the operators to install and use.
The third key concerns are the power supplies to the cameras and monitors. Currently, the researched monitors are able to use a typical car battery. Without too much effort, the system could either be powered by a car battery, or be fitted with a simple cigarette lighter adapter. The camera situation could be somewhat difficult as it will most likely be located on the digger or truck bed itself, which are all exposed to the environment. With the long work days of harvest season, standard AA and other batteries will not suffice. Mounting a car battery on the harvester is the forerunning solution for this issue; with its long life and availability it could provide ample power for the camera(s).
COST ESTIMATES
From the latest research, a list of costs for the features has been compiled in Table 2.
Table 2: Preliminary Costs of Features
Item / Cost6 Inch LCD Panel / $150
900 MHz Wireless Camera & Transmitter / $80
900 MHz Wireless Receiver / $40
2-Way Radio System / $80
Voice Activated Mic & Headset / $20
Injection Mold Enclosure / $25
TOTAL / $395
This table shows cost analysis is for the first prototype. It is likely the price will decrease as decisions are made on the final types of components, order increased quantities, and order through vendors. With the superior communication capabilities provided by the PCSys, a higher price is justified.
DETAILED PROJECT PLAN
From the recent design review, the design issues were established and developed into a prioritized list seen in Table 3.
Table 3: Prioritized list of tasks.
Priority / Area of Concern / Task to be Accomplished / Deadline1 / Camera Mounting (Vibrations) / Research steady cam, decide on method. / Jan. 26
2 / Electronic Package (Receiver, Monitor, Radio) / Research steady cam, decide on method. / Feb. 2
3 / Power for camera and monitor / Research steady cam, decide on method. / Jan. 26
4 / Dust and moisture on camera / Research steady cam, decide on method. / Jan. 26
5 / Mounting for monitor/receiver / Research steady cam, decide on method. / Feb. 4
6 / Video, Character Gen. / Research steady cam, decide on method. / Feb. 11
With this list, the E-Team will be able to focus on the most pressing issues first to ensure the designs will be completed early spring semester.
CONCLUSION
Given the E-Team’s new direction, Figure 3 shows the timeline for the rest of the project.
Figure 3: Schedule for the Remaining Year
From the research and testing performed the E-Team has decided that a camera and monitor system is the best method of communication for the application. The team also believes that the new design concept utilizing a wireless video and radio system is a product that will meet and exceed the customer’s needs. While problems will occur with this system, the E-Team believes they can be addressed with research and engineering thought process. In order for project success, the list of concerns in Table 3 will have to be resolved. The cost for this product is more expensive than the cost estimate for the old system, but this is acceptable. This product will be able to do more, it will be easier to interpret, and most importantly, it takes tasks away from the harvester driver, who is already over-loaded with tasks.