Files
smargopolo/MATLAB/motion/pvt_polynomial_algorithm.m
2019-07-31 10:49:21 +02:00

81 lines
1.5 KiB
Matlab

% Implementation of a PVT motion algorithm.
% 23.8.2018, Wayne Glettig
% Fastest track from x0 to xT, with the following given constraints:
% vmax: maximum speed of travel
% amax: maximum acceleration
% dmax: maximum deceleration
% The algorithm also takes in account start and end velocities v0 & vT
% And plots the result in (x,t), (v,t) and (a,t) plots.
%% INPUT PARAMETERS:
x0=0; %Start position
v0=1; %Start velocity
xT=-5; %Target position
vT=0; %Target velocity
vmax=0.5; %Maxium allowed velocity
amax=0.4; %Maximum acceleration
dmax=-amax; %Maximum deceleration
t0=0; %Start time
tT=20; %End Time
dt=0.01; %time step
%% CALCULATE PROFILE:
A= [t0^3, t0^2, t0, 1; ...
tT^3, tT^2, tT, 1; ...
3*t0^2, 2*t0, 1, 0; ...
3*tT^2, 2*tT, 1, 0];
b= [x0;xT;v0;vT] ;
x= A\b;
c1=x(1);
c2=x(2);
c3=x(3);
c4=x(4);
%% STEP THROUGH PROFILE WITH GIVEN SAMPLE RATE:
%Vectors for results
T = t0:dt:tT;
X = zeros(length(T),1);
V = zeros(length(T),1);
A = zeros(length(T),1);
J = zeros(length(T),1);
for (i = 1:length(T))
t = T(i);
a= 6*c1*t + 2*c2;
v= 3*c1*t^2 + 2*c2*t + c3;
x= c1*t^3 + c2*t^2 + c3*t + c4;
%Write to vectors
X(i)=x;
V(i)=v;
A(i)=a;
end
%% PLOT CURVES:
subplot (3,1,1);
plot(T, X,'r+-');
hold on;
ylabel('x(t)[m]');
subplot (3,1,2);
plot(T, V,'g+-');
hold on;
ylabel('v(t)[m/s]');
subplot (3,1,3);
plot(T, A,'b+-');
hold on;
ylabel('a(t)[m/s^2]');
xlabel('t[s]');