TSUMO (Tsunami Motion)

Have you guys seen the Tsumo? (Tsunami Motion) It's a 6DOF coin operated arcade game, there is one in the TimeZone arcade parlour near me. It's not that impressive or immersive but then again maybe that's because of it's lack of game support. It is very hard to steer and aim because of YAW and too much freedom of movement so that you constantly over correct in all dimensions.

http://tsunamivisual.com/prd_MW4.html

EvanF

This vid shows a bit better, how the mechanics work.

http://www.youtube.com/watch?v=OxWJXlYQFis

Do you think that the freewheel issue could be minimized a wee bit by arranging the cranks that way (horizontal)

regards
Christian

Wow that's some clever mechanics, everytime I went to TimeZone with the kid's I wondered what was under that shroud, now I know!
Yes it certainly looks like they have built some sort of anti freewheel mechanism into there, whether by virtue of design or by default of its articulating manner!
I wonder if we are able to design some simple elegant solution like that and whether it is within our DIY abilities and resources to build it?!

EvanF

@YoBuddy

Yes but how do you know how much PWM duty/period cycle to pump into each motor actuator to make it go into a holding pattern or a slow cycle rhythm, include the problem of different users weight variations. This is the problem I have come up with in my 3DOF platform which freewheels. The end result is a jitter as the motor cycles back and forward and this jitter varies based on what PWM frequency you pump in. If you don't include enough duty cycle the actuators go backwards if you put in too much you have too much gravelly rumble in your 'braking' as the angle encoders overcorrect as they search to maintain position.

EvanF

This may give you an idea of the problem of freewheel issue when trying to hold a given position.
I have used my 3DOF chair as an example in this simple animation.

(I can only view gif animation if clicking on it and opening in new window.)



EvanF

Hi Evan,

Yes, this arrangement of arms will surely decrease the freewheel effects! But will work only in 6-DOF platforms.

The Rumble you get in you 3DOF platform is because of the lack of PID control of the motors! The PID can be self adjusted to the load of the motor for some point making it stable! Perhaps you can try my AVR electronics that have such PID control of the motor... I tried to force a freewheel motor connected to my electronics and it didn't rumble! Just sat steady in a little lower position!!

I see that you are just using compare function on your control electronics (if > 255 goto 255, If <255 goto 255)... This is the cause of the rambling!

Perhaps I have to make a documentation video on this to understand it better!

Regards, Thanos

HI I just bought one of these and only recived the chair with motors and drives I belive they are vfds but I cant be sure they have pots connected to inverters and 3 wire operation I belive left right and position I cant find any info on the inverters but have hooked a pot up directly and the motors will move and brake in unision with rheostat but are limted to 180 degrees

I was going to buy one but there sold out right now . so I got impatient bought a 5k wire wound rheostat and am able to control motor with rheostat from 10 v dc power to signal . im going to try a low pass filter pwm to analog from Arduino running servo code from site there is quite a bit more movement in the swiveling arms then I first thought Im qurious now if this design could take the strain off wiper motors if used for 6dof, will post pics of the mechanics .

I know this is old as heck but i finnal got around to playing with the 6dof 5 year update lol ....... the controllers connected to this motion sim are vfd and operate off of pwm the closed loop system is pre programed for duty cycle from factory 0-10 v is all that is requiered for position controll ZeroV= 90Deg 10V =0Deg