Auto MowerAn Advancement in Lawn Care Technology

By: Patrick So, Sam Tat, Jackie Chui, Jeff Thai, Josh Flanagan

Content Overview

•Problem•Solution•Design Options•Final Decision•Manufacturing Process•Final Product•Future Product Developments

Problems

•Seniors and persons with disabilities are too physically challenged to push a lawn mower

•Demand exists for these people to have the ability to mow a lawn

Solution• A remote controlled lawn mower would allow a

person to mow a lawn without much effort

• Lawn mower would be controlled through radio signals

• Lawn mower would be mounted on a new frame with a new steering mechanism

Design OptionsFrame Material

1. Square Steel Tube

2. Round Steel Tube

Steering3. Tracks4. Independent

RWD5. Car like (Rack

and Pinion)Safety Covers/Shields

6. Lexan7. Plexiglass8. Sheet metal

Motors for Wheels9. Electric10.Solar11.Gas

Controls1. Radio Control

System

Design MatrixDesign 1 Design 2 Design 3

Frame Square Tube Square Tube Square Tube

Steering TracksIndependent Rear Wheel Drive

Rack and Pinion

Safety Shields Lexan Lexan Lexan

Propulsion Type Electric Electric Electric

Controls Radio Control System

Radio Control System

Radio Control System

Design Options for Steering

Decision Matrix

Design CriteriaDesign Option 1

(Tracks)

Design Option 2(Indep. RWD with Swivel

Wheels)

Design Option 3(Rack and Pinion)

Strength 95/100 95/100 95/100

Cost 75/100 90/100 85/100

Ease of Manufacturing 65/100 90/100 85/100

TOTAL 235/300 275/300 260/300

% of Total Weight 78.3% 91.7% 86.7%

Final Decisions

• Independent rear wheel drive• Electric motors• Square tube frame• Radio control system• Lexan safety shields

Rendering of the Final Product

Independent Rear Wheel Drive

Individually driven rear wheels allow the lawn mower to make precise turns. This is especially useful when the lawn mower is required to traverse through tight areas.

Electric Motors

What could be a better energy type than electricity? Electric motors are clean, efficient, reliable and cheap. Combined with two 3600 Watt-hour batteries, the lawn mower will be able to mow your lawn several times before needing to be recharged.

Radio Control System

The radio control system is the key element in making the lawn mower effortless to use. With a range of 2000 feet, the lawn mower will be able to cover even the biggest lawns.

Safety

Safety is a top concern of the project's engineers. This is why remote control failsafe switches were added to the lawn mower so that the entire unit shuts off immediately if it is out of range of the remote control. Lexan polycarbonate shields will be added in a future revision to not only protect people, but protect the lawn mower from damage due to foreign objects or weather.

Steel Tube Frame

The frame of the lawn mower is constructed using square steel tube. This kind of tubing is cheap and easy to cut & weld, minimizing the cost of manufacturing and, most importantly, the price. Steel is also very tough, so the lawn mower will be able to endure rigorous terrain and harsh weather for years.

The Manufacturing Process

The Manufacturing Process (cont.)

The Manufacturing Process (cont.)

Completed Auto Mower

Auto Mower in Action

Future Developments• Lexan polycarbonate shields will be added.

• The entire lawn mower – the lawn mower itself and the drive system – will be powered using electricity from the batteries.

• Reduce manufacturing costs; design a more compact frame.

QUESTIONS?