Robo Builder Web Site - Just Money Robots

A practical application, where we are applying the robot racer's navigation and obstacle avoidance system to, is an automated mower. University of Maryland gave us a Scag 52" hyrdo walkbehind platform to us to evaluate our system's effectiveness at real life mowing. See video

Commericial mowing labor is about 60% of gross income.

We finally got the mower traveling along parallel lines with our PID controller using RTK corrected gps(real time kinematic provides sub inch accuracy). Here's a video clip of PID RTK gps feedback line following.

Mower tracking with RTK GPS.

The PID controller should also work for curved line following. Nice for going around trees, shrubs and flower beds as well as mowing irregular spaces.

Next the mower needed a simple way to setup each mowing site.

Software was developed to first define the mowing site perimeter. So far we have a simple cad method of drawing the polygon and a second method of capturing the GPS corner coordinates. By scanning a survey map or aerial photo as a background, the perimeter drawing method provides fast job setup. Once on site the system will ask to user to capture the GPS of two or more reference points which will automatically scale and register the site map.

We used the second method and captured the Phillip's farm test site (see photo to left) and then developed a program to Auto generate the virtual lines that the PID controller will then follow. This software is now running on the mower and works great. Here it is shown on the tracking screen.

This user interface will make it simple to setup and control mowing. Mowing patterns to be supported are vertical, horizontal, diagonal patterns as well as following the perimeter then spiraling inwards in concentric swaths.

Additionally, we will use this interface to capture human produced mowing patterns and then have the PID controlled mower follow them.

The perimeter map also provides a safety feature which will shut off the mower when the mower passes outside the perimeter.

Inside obstacle perimeters will be added to allow the mower to steer around known obstacles. These will be hand drawn and also captured by sensors as the mower mows.

Upon the first mow, the GPS system will capture altitude data for each GPS point. This will be used to generate a nice 3D terrain map of the site. This terrain map will in turn allow better mower speed and direction control on steep and uneven terrain.

Luckily the racer, mower, excavator, skid steer and troweling machine all have track steering so the steering and navigation systems are all the same. This allows us to spread our development costs across many applications. As a result we can provide better and cheaper solutions to each product. Since we are designing to very demanding requirements of the racer, which needs to detect obstacles far away and react very quickly, we will have a system that performs above and beyond the needs of the slower moving applications.

Buck Bartley's equipment that is currently being Robo-ized:

The Bobcat mini excavator - Dec 9, 2002 - Stick & Bucket controls, Stick flex sensor, Control rig, the whole system - Dec 10, 2002 Bobcat simulator

NH Skid Steer Loader

Equipment manufactures are welcome to donate their equipment for autonomous control

Here are some pictures of various elements of our current projects:

The Brain

Light force steering (for Bobcat mini excavator)

Backhoe Arms/bucket swing controls( for mini excavator)

Positioning sensors (gyro, accelerometer, photoresitor, laser triangulator, and arm/bucket/swing angle sensor)

Range Collision avoidance sensors(short range IR triangulator, medium range ultrasonic, long range ultrasonic)

Heavy force Air steering system(for New Holland Skid loader)

Air steering relays