SJSU Remote Inspection Device (RID)
SJSU Remote Inspection Device (RID)
The focus of the SJSU RID is to design and build a wireless controlled robot that can navigate disaster sites.
The focus of the SJSU RID is to design and build a wireless controlled robot that can navigate disaster sites. Read more
Who are we?
We are mechanical engineering students from San Jose State University working on our mechatronics-based senior project. The group consists of members Fabian Saldana and Hector Luna-Ramirez. Each member has different strengths that make for a well-rounded team.
What is RID?
The objective of the San Jose State University Remote Inspection Device (SJSU RID) project is to design and build a remotely-operated, proof-of-concept vehicle for inspecting hazardous environments. The RID will feature a track system for maneuvering in rough environments, an arm with a 3ft reach, wireless video and wireless operation. The team members decided to participate in the RID project because it would provide them with an opportunity to create a tool for helping others. The team intends to enter the SJSU RID project in the 2013 ASME Design Competition in Long Beach, CA on April 26 & 27.
How are we doing it?
We estimate the total weight of the RID to be around 100 lbs. and will be constructed using Aluminum 6061. The dimensions of the RID will be 28” (L) x 18” (W) x 10” (H).
Moving this weight around will be two 24 volt Invacare Storm 4500RPM electric motors. These motors come equipped with gear boxes and are designed for high torque applications such as electric wheelchairs. The drive motors will be powered by a Sabertooth 2×60 regenerative motor controller from Dimension Engineering. The Sabertooth allows for a multitude of signal inputs to control the drive motors making it a flexible and powerful controller.
Drive motor and controller test video: http://youtu.be/02WubUARTpI
Powering the entire system are two Werker 12 volt 20 amp-hour deep cycle batteries. A power distribution block and/ or buck converters will be used to distribute power to lower voltage sub-systems such as servos, microcontrollers, and wireless video equipment.
The track system is a work in progress. The team is near a final decision on which way to go with this. Shown below is the team’s first attempt at a track system and some alternatives.
The 2 link arm will consist of a gripper, 2 link sections, elbow joint, shoulder joint, and rotation base joint. The gripper will be a two finger gripper with the ability to tilt and rotate. It will be driven by 3 high torque servos.
The links are 1.5ft long sections of extruded aluminum, which are light weight and rigid, making them ideal for our application.
To drive the elbow joint, the RID will be fitted with Invenscience’s Torxis servo that provide up-to 1600 oz-in (8.3 lb-ft) of continuous duty torque.
Due to the length of the arm, the shoulder joint will require a tremendous amount of torque. Unable to find a commercially available servo with the high torque requirements necessary to drive the arm, a patent pending servo was designed. This servo will yield 5000 oz-in (26 lb-ft) of torque and only weight 4 lbs.
The base joint consists of a Torxis servo that provides the rotational movement for the arm.
The RID will be controlled via wireless communication between two Arduinos, one on the RID and the other in a control panel. Two XBee Pro S1s will be used for the wireless communication. The XBee Pro S1s operate on the 2.4GHz 802.15.4 wireless standard. The 60mW signal output allows for 250kbs data transfer rate with a line of sight range of 1 mile.
The wireless video system consists of three Foscam FI8910W cameras. The three cameras will be strategically placed on the RID to ensure the operator has an optimal view of the environment. Theses cameras offer a variety of wireless features such as 640x480 resolution video, inferred night vision, pan and tilt control, and two-way audio. The operator will interface with the cameras via a computer at the operating station. A secure wireless network will be implemented to allow communication to the wireless cameras.
The team has access to a home workshop equipped with tools they have purchased over the course of several projects. These tools range from a common socket set to a router table. The team will be doing much of the manufacturing themselves in order to reduce the cost of the project as well as to demonstrate what can be accomplished with relatively inexpensive tools.
When will we complete the project?
It is the intention of the team to compete in the 2013 ASME Design Competition in Long Beach, CA on April 26 & 27, therefor the RID needs to be operational by that date. We will have until May 5 2013 to put some finishing touches and prepare it for the end of semester presentations.
How will the money be spent?
Up until now, all funding has been provided by the two team members. The team felt that this was an important first step in convincing others of the sincerity of its intent: we couldn't very well ask people to donate their hard-earned money to the project without first spending our own. The money that has already gone into the project has been spent on some of the major components and prototyping design alternatives. As a result, the team is aware of what works and what doesn't. The team has a plan in place to complete the RID project but requires additional funding to make it happen. All funds being donated to the team will be used to complete the RID and for travel expenses to the competition. Some components that still need to be purchased include but not limited to: track system, sensors, joysticks, wire connectors, fasteners, power distribution system, wireless router, video equipment, software and high-torque servos.
Risks and challenges
While both team members have experience operating metal lathes and milling machines, other obligations such as work and classes made spending hours in a machine shop making parts impractical. Therefore, the team had to rely on the craftsmanship and schedule of several “professional” machinists. Going this route, you run the risk of receiving machined parts that are of poor quality with regard to fit and finish, longer than expected turnaround times, and a huge bill. From this experience, the team concluded that it would be best to include machining time into all future projects and do as much of this work as possible in-house. In addition, it is important to have several contingency plans in place in the event that a situation doesn’t go as expected.
With only two participating members on the RID team, funding the project has proved to be the real challenge. This has required the team members to tighten up their budgets and to make the best use of the tools they have available. “As a result of our own personal pursuits and hobbies, Hector and I have acquired a fairly good set of tools and machinery over the years. This has allowed us to do almost all of the work at home and at a time that is convenient for us. While the initial investment was high in some cases, these tools have paid for themselves many times over in both time and money.”Learn about accountability on Kickstarter
- (21 days)