Parameters - Revision history

Frohro: /* Inverted Penululm Project *

2011-03-10T00:01:41Z

/* Inverted Penululm Project *

← Older revision		Revision as of 17:01, 9 March 2011
Line 88:		Line 88:
	b2 = 2a2J2; % Nms/rad Viscous friction of pendulum 2 (rotational)		b2 = 2a2J2; % Nms/rad Viscous friction of pendulum 2 (rotational)

	scale = [rd2pi/4096 2*pi/4096 -0.05/250];
			% It appears that the labels on the pendulum for positive x
			% and negative x are backwards, and it appears that the angle
			% for theta is also backwards. It is really CW is positive,
			% not CCW. A positive pwm value to the motor moves the pendulum
			% toward what is marked as NEG x (to the right).
			% I made the scales below reflect that to correct the sign problems
			% with the measured variables. You must correct the motor voltage
			% in your code.


			scale = [-rd2pi/4096 -2*pi/4096 -0.05/250];

Frohro: /* Pendulum Hardware Control */

2011-03-09T19:24:56Z

Pendulum Hardware Control

← Older revision		Revision as of 12:24, 9 March 2011
Line 210:		Line 210:
	global ctrlbox_con;		global ctrlbox_con;

	pwm = min(max(cmdval*32767,-32000),32000);		pwm = min(max(cmdval,-32000),32000);
	data = [pwm, 0, enable, period];		data = [pwm, 0, enable, period];
	send(ctrlbox_con, typecast(int32(data(1:4)),'uint8'));		send(ctrlbox_con, typecast(int32(data(1:4)),'uint8'));

Frohro: /* Pendulum Hardware Control */

2011-03-09T14:06:18Z

Pendulum Hardware Control

← Older revision		Revision as of 07:06, 9 March 2011
Line 139:		Line 139:
	% send sample period		% send sample period
	period = 1000000./srate;		period = 1000000./srate;
	~~fprintf('period: %d %x\n',period,int32(period));~~
	ctrlbox_send(0,0,period);		ctrlbox_send(0,0,period);

Frohro: /* Pendulum Hardware Control */

2011-03-08T02:11:55Z

Pendulum Hardware Control

← Older revision		Revision as of 19:11, 7 March 2011
Line 95:		Line 95:
	===Pendulum Hardware Control ===		===Pendulum Hardware Control ===

	Here is a pendulum hardware control script that should help with yours:		Here is a pendulum hardware control script that should help with yours. You basically need to modify tcpdemo4 (immediately below) with your control code in the appropriate place.

	% tcpdemo4 - demo script to communicate with new pendulum interface		% tcpdemo4 - demo script to communicate with new pendulum interface
Line 178:		Line 178:
	% disable motor and disconnect		% disable motor and disconnect
	ctrlbox_shutdown();		ctrlbox_shutdown();

			The function ctrlbox which is used above is given below for your edification.

	% ctrlbox.m		% ctrlbox.m

Frohro: /* Pendulum Hardware Control */

2011-03-08T02:07:46Z

Pendulum Hardware Control

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Frohro: /* Pendulum Hardware Control */

2011-03-08T02:05:43Z

Pendulum Hardware Control

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Frohro: /* Pendulum Hardware Control */

2011-03-08T01:50:49Z

Pendulum Hardware Control

← Older revision		Revision as of 18:50, 7 March 2011
Line 110:		Line 110:
	% receive data:		% receive data:
	% enc0, enc1, enc2, enc3		% enc0, enc1, enc2, enc3
			% enc0 is the long pendulum angle
			% enc1 is the short pendulum angle
			% enc2 is the angle of the encoder of the motor
			% enc3 is the knob control
			% All encoder values are 4096 counts per revolution except enc3.
	%		%
	% command value is -1.0 full scale negative motion, +1.0 full scale		% command value is -1.0 full scale negative motion, +1.0 full scale

Frohro: /* Inverted Penululm Project */

2011-03-08T01:37:14Z

Inverted Penululm Project

Show changes

Frohro: /* Inverted Penululm Project */

2011-03-08T01:20:21Z

Inverted Penululm Project

← Older revision		Revision as of 18:20, 7 March 2011
Line 92:		Line 92:

	T = 1/f;		T = 1/f;

			===Pendulum Hardware Control ===

			Here is a pendulum hardware control script that should help with yours:

			% tcpdemo4 - demo function to communicate with new pendulum interface
			%
			% Syntax:
			% tcpdemo4
			%
			% cnt is number of packets to receive
			% val is max amplitude in volts
			% srate is sample rate in Hz
			%
			% communication with the new ctrlbox is by the ctrlbox.m library
			%
			% receive data:
			% enc0, enc1, enc2, enc3
			%
			% command value is -1.0 full scale negative motion, +1.0 full scale
			% positive motion
			% encoder data is 32 bit raw counts
			%
			% protocol is send command value, then read encoders. Sampling in feedbox is
			% done according to a hardware sample clock.
			%
			pkg load sockets control;
			ctrlbox; % load ctrlbox comm functions

			cnt=4000; % number of times through loop
			srate = 400; % sample rate in Hz

			store = zeros(cnt,5);
			rdata = [0,0,0,0]; % receive data

			% Connection must first be established with the ctrlbox.

			try
			ctrlbox_init();

			disp('finished init');

			% send sample period
			period = 1000000./srate;
			fprintf('period: %d %x\n',period,int32(period));
			ctrlbox_send(0,0,period);

			disp('finished send');

			x = 1:cnt;
			tic;
			for c=1:cnt
			% read encoder values
			rdata = ctrlbox_recv();

			%
			% your control law goes here
			%

			cmdval = sin(6.288double(c)/min(cnt,1000));

			% write pwm values and enable motor
			ctrlbox_send(cmdval, 1, 0);

			% force matlab to check for interrupts and flush event queue
			drawnow;

			% save data
			store(c,:) = [rdata,cmdval];
			end
			runtime = toc;
			fprintf('transactions=%d seconds=%d transactions/sec=%f\n',
			c, runtime, c/runtime);
			drawnow;

			catch
			% if something failed, display error and loop count
			fprintf('c=%d\n',c);
			disp(lasterror.message);
			end
			% disable motor and disconnect
			ctrlbox_shutdown();

			ctrlbox.m
			% ctrlbox.m
			%
			% Functions for communication with the inverted pendulum
			% ctrlbox interface via ethernet.
			1;
			%
			% ctrlbox_init - initialize connection to ctrlbox
			%
			function rval = ctrlbox_init()
			global ctrlbox_con;

			ctrlbox_con = socket();
			sinfo = struct("addr","169.254.0.100", "port", 47820);
			rval = connect(ctrlbox_con,sinfo);

			return;
			endfunction
			%
			% ctrlbox_send(cmdval,enable,period)
			% - send command value, enable, and sample period to ctrlbox
			% - cmdval = -1.0 to +1.0, where 1.0=100% of DC bus voltage
			% - enable = 0 or 1
			% - period in usec
			%
			% - future: measure time avg of pwm value, shutoff motor
			% if excessive.
			function rval = ctrlbox_send(cmdval,enable,period)
			global ctrlbox_con;

			pwm = min(max(cmdval*32767,-32000),32000);
			data = [pwm, 0, enable, period];
			send(ctrlbox_con, typecast(int32(data(1:4)),'uint8'));

			rval = 0;
			return;
			endfunction
			%
			% ctrlbox_recv - receive an array of four values from ctrlbox
			%
			function data = ctrlbox_recv()
			global ctrlbox_con;

			[rdata,len] = recv(ctrlbox_con,16);

			if (len ~= 16)
			fprintf('short data: %d\n', len);
			end

			data = double(typecast(rdata,'int32'));
			return;

			endfunction

			%
			% ctrlbox_shutdown - shutdown connection to ctrlbox
			%
			function ctrlbox_shutdown()
			global ctrlbox_con;

			% turn off motor
			send(ctrlbox_con,typecast(int32([0,0,0,0]),'uint8'));

			disconnect(ctrlbox_con);
			endfunction

Frohro: Created page with '== Inverted Penululm Project == Below is some Octave or Matlab code with the parameters of one of the pendulums. % Double Pendulum Parameters (Tentative: There are two pendulu…'

2011-02-23T18:03:54Z

Created page with '== Inverted Penululm Project == Below is some Octave or Matlab code with the parameters of one of the pendulums. % Double Pendulum Parameters (Tentative: There are two pendulu…'

New page

== Inverted Penululm Project ==
Below is some Octave or Matlab code with the parameters of one of the pendulums.

% Double Pendulum Parameters (Tentative: There are two pendulums with different parameters. I'm not sure which these go to.)

% Run parameters
%f = input('Control Frequency (Hz) = ');
%crad = input('Pole Radius (1/s) = ');
%psi = input('Spreading Angle (deg) = ');
%eta = psi*pi/180;
%obshift = input('Observer Shift = ');
%Trun = input('Run Time (s) = ');
f=130;
crad=19;
psi=10;
eta=psi*pi/180;
obshift=2;
Trun=60;

kmax = round(f*Trun);
T = 1/f;
Maxpos = 0.25; % Max carriage travel +- 0.25 m
Maxangle = 0.175; % Max rod angle -- 10 deg
Maxvoltage = 20; % Max motor voltage, V
pstart = 0.005; % Carriage position starting limit, m
astart = 1*pi/180; % Angle starting limit, rad

g = 9.81; % m/s^2 Gravitational constant

% SYSTEM PARAMETERS
% Measured Mechanical Parameters
d1 = 0.323; % m Length of pendulum 1 (long)
d2 = 0.079; % m Length of pendulum 2 (short)
%mp1 = 0.0208; % kg Mass of pendulum 1
mp1 = 0.0318;
%mp2 = 0.0050; % kg Mass of pendulum 2
mp2 = 0.0085;
m = 0.3163; % kg Mass of carriage
rd = 0.0254/2; % m Drive pulley radius
md = 0.0375; % kg Mass of drive pulley (cylinder)
%mc1 = 0.0036; % kg Mass of clamp 1*
%mc2 = 0.0036; % kg Mass of clamp 2*
mc1 = 0.0085;
mc2 = mc1;

% *Clamp Dimensions
% Rectangular 0.0254 x 0.01143 m
% The pivot shaft is 0.00714 m from the end

% Motor Parameters (Data Sheet)
Im = 43e-7; % kg m^2/rad Rotor moment of inertia
R = 4.09; % ohms Resistance
kt = 0.0351; % Nm/A Torque constant
ke = 0.0351; % Vs/rad Back emf constant

% Derived Mechanical Parameters

% kg m^2/rad Moment of inertia, clamp 1
%Ic1 = mc1*(0.01143^2 + 0.0254^2)/12 + mc1*(0.0127-0.00714)^2;
Ic1 = mc1*(0.0098^2 + 0.0379^2)/12;
Ic2 = Ic1; % kg m^2/rad Moment of inertia, clamp 2
Id = md*(rd^2)/2; % kg m^2/rad Moment of inertia, drive pulley
Imd = Im + Id; % kg m^2/rad Moment of inertia, combined

J1 = Ic1 + mp1*(d1^2)/3; % Total moment of inertia, pendulum 1 (long)
J2 = Ic2 + mp2*(d2^2)/3; % Total moment of inertia, pendulum 2 (short)
Jd = Im + Id; % Total moment of inertia, motor drive
Mc = m + mc1 + mc2; % Total carriage mass

% Friction Test Data
% Carriage Slope = 19 deg; Terminal Velocity xdotss = 0.312 m/s; From
% twincarriage.m; formula b = m g sin(theta)/xdotss
% Pendulum 1 (long) Exponent a1 = 0.0756 1/s; From longfit.m
% Pendulum 2 (short) Exponent a2 = 0.2922 1/s; From shortfit.m
% formula b = 2 a J

%alpha = 19;
alpha = 12.2;
%xdotss = 0.312;
xdotss = 0.4852;
%a1 = 0.0756;
%a2 = 0.2922;
a1 = 0.0185;
a2 = 0.012;
% Ns/m Viscous friction of carriage system
b = (Mc + mp1 + mp2)*g*sin(alpha*pi/180)/xdotss;
b1 = 2*a1*J1; % Nms/rad Viscous friction of pendulum 1 (rotational)
b2 = 2*a2*J2; % Nms/rad Viscous friction of pendulum 2 (rotational)

scale = [rd*2*pi/4096 2*pi/4096 -0.05/250];

T = 1/f;