Robotic Vehicle Platform: Background Presentation

1. Robotic Vehicle Platform:Background Presentation Steven Rois (ME) Chris Wakeley (ME) Kenneth Smith (ME) Andrew Krall (ME)

2. Mission Statement "The mission of this family of projects, within the Vehicle Systems Technology Track, is to develop a land-based, scalable, modular open architecture, open source, full instrumented robotic/remote controlled vehicular platform for use in a variety of education, research & development, and outreach applications within and beyond the RIT KGCOE. The family of projects should use an engineering design process to develop modules and subsystems that can be integrated by subsequent senior design teams. Project P07200 serves as the foundation or starting point for a series of senior design projects.” RP Family Page (P07200) https://edge.rit.edu/content/P07200/public/Home

3. Project Iterations • Started 2006-1 • RP 10 and RP 100 platform projects were started in 2006-2007 • Motor modules for RP 10 and RP 100 were started in subsequent quarters in 2006-2007 • 1st Generation RP 1 motor modules started 2007-2 • 2nd Generation platform for RP 10 started 2007-1

4. Personnel Advisor: Dr. Wayne Walter Primary Customer: Dr. Ed Hensel Resources/Funding: RIT, Gleason Foundation, Dresser-Rand Corporation End Users: KGCOE, RIT student body, faculty research, public, hobbyists/enthusiasts

5. Robotic Platform • RP 10 and RP 100 must be able to carry 10kg and 100 kg payloads • Must feature scalable and modular motor modules arranged in a variety of configurations • RP 10 must have a range of one floor of bldg 9 • RP 100 must have a range of the entire bldg • Be able to have skid steering and turn steering (2 wheel drive) • RP 10 and RP 100 were started in 2006-1 • Battery powered (DC) • Size Constraints (RP 100 - 1m3, RP 10 - 1ft3)

6. RP Platform Progression Fully enclosed structure Mounting area for payload 4 wheels-more stable control/operation Fully enclosed Modular wheel attachments Lighter body Fewer components Simpler controls RP 100 3 wheel RP 100 4 wheel RP 10 Small payload area Issues with stability/handling Containment of sensitive components More complex controls Inefficient use of space Heavy/bulky Low ground clearance Component layout may lead to issues Heavy/bulky Inefficient use of space

7. Sensors and Vehicle Data Acquisition • 2006-07: Vehicle Data Acquisition P07301 • This student team was assigned to develop a fully functional, scalable sensor module subsystem. The project hardware and software was designed to support mechanical, electrical and applications software projects. • System Specifications • PC104 Lynx Board • Processing board running Linux to maintain open-architecture • Input Board w/daughter boards • Designed to provide accurate digital signals to be collected by the PC104. • Output • Designed to have 4 channels in the 0-5 V range and 4 channels in the +/-12 V range

8. Sensors and Vehicle Data Acquisition Main Issues Overcome by P07301 Team Output Format: The PC104 could be responsible for converting the binary numbers to ASCII, or the PC104 can send the binary information to the host PC to convert later. Precision of 250 Ohm resistors for current loop output. High precision --> High cost No circuitry to accommodate the output range Not enough current (200mA) to support the PC104 and current output. Current A/D converter does not have anti-aliasing filters or programmable gain. No regulated 12V supply Figure 2: Final input board with daughter boards

9. Motor Modules • Self-Contained drive/steering module. • Torque necessary to move payload (1-100kg). • Top speed of 4.5 m/s. • Same module can be driven or idle. • Steering angle range of 360°. • Support 3, 4, or 6 wheel arrangements.

10. Motor Modules Safe, enclosed drivetrain Electronics isolated from moving parts Strong & versatile frame Modular gearbox Infinite rotation Robust Size/weight – 1/10 of gen 1 Easy to manufacture Meets all RP1 specifications RP100 & RP10 Gen 1 Shaft alignment friction High cost & weight Poor manufacturability Time consuming disassembly Belt and gear skip under load RP1 Gen 1 No belt tensioner Steering rotates driveshaft No smaller than RP10 RP1 Gen 2 Low quantity production cost is high

11. Motor Controls • The Motor Control subsystem contains the inputs used to actuate the motors, but does not contain the motors or driver circuitry itself. The controls subsystem generates the timing and control signals, which are then fed into the Motor Modules subsystem. • Build a control system to command interchangeable motor modules • Control system must be: • Open-Source, Open-Architecture • Modular • Scalable, Programmable • Control system must be controllable by payload or Windows/Linux PC • System must be smaller than previous units

12. Motor Controls • Overall well executed, effective design of the motor controls. • Oversized for application, minimal heat loss, high efficiency • Easy to troubleshoot with multiple status LEDs • Modular and stackable design • Easy to connect all inputs,outputs and power cables • Ability to turn, drive, and stop based on commands issued by the user • Open-source, Java readily available RP1 Gen 2 RP1 Gen 1 • Microcontroller did not have the capacity to generate all necessary control signals • Stepper motor drivers had non-deterministic behavior, required excessive control signals RP10 Gen 2 • One direction communication with the MM • Only set up to work with one MM • Future recommendations: • Decrease size of PCB • Protect against reversed power connections • Add current limiting resistors on all IC output pins to prevent damage to chips due to short circuit conditions. • Future recommendations: • Merge power supplies • Merge microcontrollers • Merge DC Drivers

13. Questions?