Group SD0623
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Group SD0623 -- Bucket Sensors (Bobcat Co.)
MEMBERS:
Tyler Mosset, Kristopher Deaustin, Justin Peterson, Kalvin Hoff
INTRODUCTION:
Our group is working on a system to interface with current bobcat Skid-Steer Loaders. We are designing a system that will tell the operator of the machine critical information about the bucket and lift arms. The operator will be able to look at an LCD display while running the machine. The information that will be displayed on the LCD screen will include information such as bucket height, bucket angle, arm height, and it will also take into account whether the machine is tilted in any way, such as sitting on a side hill or going up or down a hill.
This information is critical to the operator of the machine for many reasons. Some forms of work require that you know exactly how high the bucket is, allowing you to clear obstacles. You might encounter this when you are loading such things as trucks or carts.
REQUIRMENTS:
- Operate off 12V DC power supply
- Filter power supply to eliminate noise
- Measure height within 3cm of accuracy
- Measure angle of bucket relative to the Bobcat skid-steer
- Detect the skid-steer angle relative to earth
- Endure all kinds of environmental conditions
- Physical size must be as small as possible
- Minimize cost
- Create user friendly display
- Use microprocessor to process information from sensors
OPTIONS CONDSIDERED
There were A few different options that were considered in the design of this system. A possible design was considered that used sensors mounted on the hydraulic system of the machine. These sensors would measure the amount of hydraulic fluid going through the hoses. There was also a possibility that we could measure the pressure from the hydraulic cylinder. This option was not chosen for a few reasons. To effectively minimize cost and resources we decided that this method was not efficient. A few other reasons also contributing to the decision were mechanical factors. We decided that this type of system would have a few weak points using the hydraulic system. If there were a leak in the hoses or cylinders this would affect the readings of the instruments. This is often a very prominent problem as machines get older and hoses and seals start to wear out.
This picture is of our 1/3 scale model of a Bobcat lift arm. The sensors that are mounted are inclinometers that measure angles. Sensor 1 on the bucket reads the angle of the bucket. Sensor 2 will allow us to determine the height of the bucket. And sensor 3 represents the chassis of the machine, this tells us what kind of plane the machine itself is on. If the Bobcat is on unlevel ground this will affect how high the bucket is off the ground.
This is a photo of your final PCB board. The main components are the 2 PIC processors, the A2D chips, and the max filters.
This is a photo of the control side of our enclosure.
This is a photo of the LCD output. It is diplaying height in inches and the angle of the bucket in degrees. Also front/back and left/right measurments are in degrees. It also shows with machine is being uesed Vertical or Radial.
