Ramblin' Dan's Workshop

The Sanctum of Fine Art and Invention

Remote Conning System

This is a remote control (R/C) system I am developing for a computer based control systems of a model boat. Rather than conventional old school methods, this uses a high speed TWO WAY data link between the model boat and the operator. This opens a whole new way monitoring the remote controlled object and an unlimited number of special features. Read On.

The Remote Conning System (RCS)

Thoughts on Advanced Applications for RCS

This is a new concept of the Remote Operated Vehicle (ROV) or Remotely Piloted Vehicle (RPV) control applied to scale model boats. RCS is intended to provide realistic scaled control rather than real time instant response. That is why the term conning system is used. However, the concept can be utilized in any type of remote vehicle control when the human response time is not critical (fast). In this affordable system the display and use of the feedback will be generally too slow to be of use or value in any high speed real time application.

Reasonable application of  ROV control has been accomplished for explorer rovers both on land and under water and long range RPV aircraft of many types. The process is also well established in space and other distant world exploration but response is limited by radio signal delays. Low speed ROV's are used to fulfill missions in the scientific, military, or hazardous investigation areas. All these applications are well established using the RCS type of feedback and are part of the inspiration for use of RCS in slow speed scale model boats.

Currently using RCS in the real time (speed and directional) control in standard R/C small field type model aircraft and all forms of high speed R/C model competition vehicles is not realistic. Scale slow operation is not desired. Data gathering and recording for later historical retrieval is the best application of RCS in these operating conditions. Speed and direction control must always be real time.

Operation of slow speed scale models could be made realistic in their rate of motion and directional control with RCS. In these cases, I am not proposing exact response scaling as I carefully selected the term realistic. The concept is the selective use of the RCS computer to introduce scale like response to commands from the com with complete override in panic situations.

This concept has been used in model train systems to provide realistic type locomotive and train operation for acceleration, drifting and braking.

A high tonnage warship certainly responds differently to helm and engine commands than a high speed personal sport runabout. The heavy ship will take a lot longer to power up, down and stop. Many boat and ship models can be grossly overpowered so they react with far better performance than the prototype craft.

With RCS it is possible to build “canned” effects into manual input and autonomous control sequences. Remember the sequences can be optional and turned off on on at will with proper programming (command) of the RCS computer.

My vision is the shore (captain's) control will include a key pad as part of the interface. Any predefined control sequence can thus be sent to the TCS computer from the key pad via the data link to change on-board sequence of operations.

The key pad can also be used for control of any accessory or routines to control accessories. For example an entry code 789A might be used to turn on a mast light. Then code 789B used to start a computer sequence to blink the light on and off in one second intervals like a beacon. Finally 789C shuts the mast light off. It is all up to the imagination of the programmer and number of I/O pins with how they are programmed. That means there is almost no limit of the number or variation of realistic control functions available.

There are ways to extend control by using multiple processors to add additional I/O capabilities. That is far beyond the original scope of the RCS but certainly not unreasonable.

More Brains

I just made another investment in the hardware for the Remote Conning System (RCS). I sent a big order to Parallax for more computer goodies. Here is the list:

2-Axis Joystick 27800
4x4 Matrix Membrane Keypad 27899
Compass Module 3-Axis HMC5883L 29133
Parallax (Futaba) Standard Servo 900-00005
Parallax 4x20 Serial LCD (Backlit) 27979
PMB-648 GPS SiRF Internal Antenna 28500
Propeller C3 Full Kit 32205
Propeller Peripherals Kit 32311

You can look it all up if you want to know the cost but for me the lowest cost is NOT a determining factor. I am looking for function. I am also single sourcing (Parallax) as much as possible to keep parts acquisition as KISS as possible. If I was building for production I would do more homework in this area.

Items

I selected the joystick for testing as an initial human interface for speed forward and reverse and for rudder control. Eventually I will be driving the dual motors and dual rudders separately. Just because I can. That will provide the most flexibility in programming and in boat operation.

The keypad is another human interface for the RCS. Keypad entry will provide an unlimited number of input commands to the system. Type in course or speed for example. *** could be emergency all stop. #01 could be turn on running lights. Like I said, unlimited input control.

The compass can be used for autonomous navigation or a direction feedback to the display on the shore unit.

The second servo is so I can have a separate servo for each rudder. I think they will usually be slaved together but I may want to experiment with individual rudder control. It also supplies redundancy in rudder control.

The 4x20 LCD text display can be used on the shore unit to display system information. I envision the shore unit not attached to a PC computer. I will consider possible PC tethering by Bluetooth or WiFi link.

The PMB-648 is a GPS unit. There is a lot of uses for this device. True speed and direction reporting, autonomous navigation, repeat previous course, return to start, and hundreds of other direction control ideas. It is the heart of the RCS.

The C3 Propeller is a new credit card size version of the computer system. No, it's not a propeller on the end of the motor drive shaft. Ha! It contains some I/O on board and is the right size for the RoboBoat on-board computer. I won't be using some of the I/O like video on the boat but that is of no consequence. I will be using it for development or system debugging.

The peripherals are some extras I am treating myself to, while I figure out how to use the Propeller. It provides a case (probably not suitable for use in the boat but good protection for bench testing), a small video screen and a mouse and small keyboard. I have keyboards and mice but they were low cost with the kit.

So that does it for now. I need to be working out any layout problems with the electronics before I get the boat hull too far closed up for required modifications. I am concerned about interaction between the GPS receiver and the transmitted signal from wireless modems. They may need to be isolated as much as possible. There may also be noise problems from the motors and speed controllers or even the Propeller GPU itself.(I haven't seen that in my initial tests.)

Lots of what ifs to consider but this is the fun I enjoy on this kind of project. A perfectly operational boat out on the pond is a goal. But the fun I get is in the journey to that goal.

C3 Propeller

c3-6c3-7

I have my new Parallax C3 Propeller micro computer running (or is it spinning?) and put it through its initial tests. It is accepting a standard keyboard input and outputting to a small NTSC video screen. It also has a VGA output I haven’t tested. NTSC video only requires 3 output pins on the CPU and the VGA needs 8. That means there is much less CPU overhead to run NTSC video.

The NTSC video output is quite adequate, good enough for a development display screen. I have seen a picture of the VGA screen output and it does look higher quality. If I can find a low cost and small VGA (well, VGA is small {640x480}) screen, I think it would be the way to go for long term use. The problem may be in finding such a low native resolution in a monitor these days. That can wait until there is a need. I have several VGA monitors I can test with.

I am evaluating the C3 for either use on the RoboBoat shore unit or the boat. Right now I have the feeling I may not use it for either as it has a lot of human interface I/O built in that I don’t need and won’t be using for RoboBoat applications. However, it is a very cool micro computer and I will certainly be writing some non-nautical applications for it. I need to get comfortable with low level assembler and high level Spin programming.

I think if I add an XBee wireless modem to the C3 I’ll be in business with a very handy stand alone wireless network terminal node for network communication and data gathering. That’s a good use for my 1 mw Xbees. I plan to move to high power 64 mw Xbees for the RoboBoat.

The C3 can be a stand alone “home base” for a wireless network home automation and control system.  If I pair up an Xbee with a Basic Stamp or another Propeller, I can dream up an almost unlimited number of wireless and non wireless applications.

  • Temperature monitoring indoor/outdoor
  • Various weather functions
  • Home lighting control
  • HVAC control system (I am an HVAC engineer)
  • Garage door monitor and control.
  • Machine control with stepper motors and RPM monitoring.
  • Amateur Radio communications and control

I have just started to scratch the surface with options but I want to keep the focus here on RoboBoat development. I may have to take the C3 to another blog if I wander too far off course.

The above has been done as the complete XBee and Parallax write up has been moved here to RD's Workshop!

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