There are a few disparate projects, eg. @gedeschaines, @adityadua24 to be pulled together and shipped.

Can I use Link object to create a link without using DH parameters (like using custom transformation matrix and frames)? if so, how? if not we should add an option to the class.

Execution of " jacob_dot(Arms(1),q,qd) " leads to
Error using *
Inner matrix dimensions must agree.

Error in SerialLink/jacob_dot (line 82)
rd{i} = cross(w{i}, a{i}) + Q{i}*rd{i+1};

To address the problem, I believe the following lines should be corrected as follows (some transposes are missing)
rd{n} = cross( w{n}, a{n})';
rd{i} = (cross(w{i}, a{i}))' + Q{i}*rd{i+1};
r{n} = a{n}';
r{i} = a{i}' + Q{i}*r{i+1};

I think the following code should work, however it outputs an error saying i didn't define the workspace option, which i clearly did.

q0 = [4,3];

L(1) = Link('theta',-pi/2,'alpha', pi/2,'a',1);
L(2) = Link('theta',    0,'alpha',-pi/2,'a',0);

R = SerialLink(L,'name','Arm');
             
R.plot(q0,'workspace',[-10,10,-10,10,-10,10]);

Error using RTBPlot.plot_options (line 755)
Prismatic joint(s) present: requires the 'workspace' option

Error in SerialLink/plot (line 212)
opt = RTBPlot.plot_options(robot, varargin);

Error in test (line 8)
R.plot(q0,'workspace',[-10,10,-10,10,-10,10]);

I can not generate the Jacobian matrix of a robot with rpy representation with CodeGenerator
I tried to modify line 59 of "genjacobian.m" to use rpy:
J0 = CGen.rob.jacob0 (q, 'rpy');
But I get the following error when generating the Jacobian:

Conversion to logical from sym is not possible.
Error in tr2rpy (line 110)
if abs(abs(R(3,1)) - 1) < eps % when |R31| == 1

Error in SO3/tr2rpy (line 278)
rpy = tr2rpy(obj.R, varargin{:});

Error in SerialLink/jacob0 (line 84)
rpy = tr2rpy(Tn);

Error in CodeGenerator/genjacobian (line 59)
J0 = CGen.rob.jacob0(q,'rpy');

It seems that the underlying problem is that the tr2rpy() function does not work with symbolic expressions, for example :

syms r p y
T=rpy2tr(r,p,y)
rpy=tr2rpy(T)

Conversion to logical from sym is not possible.

Error in tr2rpy (line 110)
if abs(abs(R(3,1)) - 1) < eps % when |R31| == 1

I'm attempting to install version 10.2 of the Toolbox on the latest Octave 4.2.1 in Arch Linux.

I've never used MatLab, Octave, or the Robotics Toolbox before, so I hope I'm not overlooking anything obvious.

I followed the directions in the readme, extracting rvctools to /usr/share/octave/4.2.1/m.
I then copied '@link', '@seriallink', and '@quaternion' to /usr/share/octave/4.2.1/m/rvctools/robot.

Calling mdl_puma560 as suggested in the readme yields the following error:

>> mdl_puma560
error: class not found: Link
error: called from
    mdl_puma560 at line 78 column 6

I tried renaming '@link', '@seriallink', and '@quaternion' to 'Link', 'SerialLink', and 'Quaternion' respectively. Then the classes seem to be recognized, but this results in a series of warnings on startup:

warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Link/subsasgn.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Link/subsref.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Link/char.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/double.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/plus.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/minus.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/dot.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/mrdivide.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/norm.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/mtimes.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/inv.m shadows a built-in function
warning: function /usr/share/octave/4.2.1/m/rvctools/robot/Quaternion/mpower.m shadows a built-in function

I am not sure if this is the expected behavior or if I have broken something...

However, now the mdl_puma560 command gets a little further, finding the class, but returning a different error:

>> mdl_puma560
parse error near line 261 of file /usr/share/octave/4.2.1/m/rvctools/robot/Link.m

  syntax error

>>>                     p = properties(this(j));
                                     ^

error: called from
    mdl_puma560 at line 78 column 6

I am a complete beginner, so I don't know what is wrong with that syntax.
I am not sure if the problem stems only from my ignorance, or perhaps from some change in Octave since the Toolbox patch was initially released, since that was now six years ago.

Thanks in advance for any support.

Index exceeds matrix dimensions.

Error in SerialLink/plot3d (line 154)
opt.ws(5) = mn(3);

Get RTB 10.x working with Octave

The code generation demo \demos\codegen.m fails in at least two points. Both are related to the recently introduced SE class framework.

• codegen.m line 130: tic; Tz2 = specRob.fkine(qz); t2 = toc Here we have qz being an SE [1x3] class instance. The symbolic toolbox does not understand, how to substitute this.

• codegen.m line 204: J02 = specRob.jacob0(qz) A breakpoint inside jacob0.m reveals that the fkine method for some reason returns a [4x4] matrix instead of an SE class instance. Hence the dot notation in line 73 (jacob0.m) fails. Strange enough, the previous call to jacob0 does not cause this issue.

All other lines in codegen.m pass.

This line strikes me as incorrect.

Vr = cross(o,D(:,i)) + v;

D is in body coordinates, but o and v are in world coordinates, so this doesn't make any sense.

Assuming Vr should be in body coordinates, I think this should be

Vr = inv(R) * (cross(o,R*D(:,i)) + v);

Create a Simulink that wraps plot_vehicle to animate a vehicle. Possible checkbox options for trail, continuous animation, start and end only etc.

should support a base transform and return the base wrench

Add omnidirectional base subclass
Add bicycle model with steering wheel rate input

Make curvature planner into Navigation subclass
Make ReedsShepp planner into Navigation subclass

when i run a command >>q = Quaternion( rpy2tr(0.1, 0.2, 0.3) ) in matlab, it failed because of lack of definition of numcols function.

Recently, I used the plot3d function, and select the 'movie' option as 'my.mp4', but I met the error 'Animate is not defined',
I really did not find the relevant file or function definition in the toolbox.
How can we solve this problem?

Prototype parser in urdfparse,m

Should be option to SerialLink constructor, perhaps SerialLink.URDF(filename)

and/or a standalone class

u = URDF(filename)
u.trchain(i)   % for i'th end effector ETS

display method shows something like [linkname]--jointname--[linkname]-- etc, maybe nicely layed out tree for robot with multiple end-effectors.

How to turn multi end-effector robot into a graph, rather than list?

Ultimately how to generalise SerialLink to ETS rather than DH? Perhaps a list of Link or ETS objects, or create a common superclass for both?

Add more corner detectors, leverage OpenCV?
Or leverage CVST?

Hey Peter,

Thanks for your work so far.

I am needing an older Version of your Toolbox (Version 9.7) for some older MATLAB-Tool-Files. Please mark the Version-Milestones in the future, so that people can easily download older Versions of your great Toolbox. Any advice on how to download this specific version?

Thanks in advance!

Add new classes to support Featherstone style spatial vectors for dynamics

Add animation movie fields to the mask for quad rotor plot and robot plot

I am opening this issue on behalf of Marc Killpack, who reported a bug on the googlegroup with the following desciption:

The problem is with the following lines of code in the "jacobe.m" file:

if isa(q, 'sym')
J(6, robot.n) = sym();
else
J = zeros(6, robot.n);
end

I think the "sym()" function has changed in later versions of MATLAB. However, after examining these lines of code, I can't tell what the purpose is except to declare those entries as symbolic variables. However, just commenting out those lines in the source code solved my problem. It may be that MATLAB is handling symbolic variables overall in a better way so I don't need these lines anymore. However, if it breaks something else, I'd love to hear if someone else sees something I'm missing.

In previous mail:
This tiny code snippet from below used to work in the toolbox last year, but doesn't seem to work any more:

syms q1 q2 q3



robot = SerialLink([Revolute('a', 0.4), Revolute('a', 0.4), Revolute('a', 0.4)]);
robot.jacob0([q1, q2, q3])

This snippet isn't particularly important, but being able to evaluate SerialLink functions symbolically was really nice. Any suggestions of what's happening?

With geometric models (cylinder, box) or STL meshes

convenience wrapper around timer and waitfor that accounts for loop delay

could be used in Animate, tranimate, tranimate2 etc, vehicle and arm animations

Change units to metres, to fix the floor tiling problem.

Reported by basvroeg, Jul 30, 2013
What steps will reproduce the problem?

1. Create a RangeBearingSenors:
2. sensor = RangeBearingSensor(veh, Map(10), V, 'range',[0.1 20],'angle',[-135 135]);
3. Seems like superclass Sensor cannot handle options from class RangeBearingSensor

What is the expected output? What do you see instead?
A range bearing sensor object with given range and angle. Instead, i get the following error:

Error using tb_optparse (line 211)
unknown options: range

Error in Sensor (line 71)
opt = tb_optparse(opt, varargin);

Error in RangeBearingSensor (line 90)
s = s@Sensor(robot, map, varargin{:});

Error in Localization (line 40)
sensor = RangeBearingSensor(veh, Map(10), V,
'range',[0.1 20],'angle',[-135 135]);

I am trying to do parameter estimation of puma 560 using this library. I am able to get the inertial parameter estimates perfectly.

1. I have a doubt if the Bm, Tc represents coefficients of Coulomb and viscous friction respectively or does it represent maximum /minimum friction limits, for ex. Tc takes a range (like: -0.1 to +0.1) as input. What does this number signify?

2. If Bm, Tc is not coefficients of Coulomb and viscous friction respectively. Is there a way to calculate the coefficients using gear ratios, Tc, Bm?

3. Is stribeck, stiction modelled in puma 560 and is it visible at low-velocity?

Thanks in advance

In the zip files available on http://www.petercorke.com/RTB/, this file exists, but I don't understand how to use the toolbox from a cloned git repo.

Running startup_rtb.m doesn't load, for example, functions under common. Actually, I don't understand in which repo those functions are hosted. (For example runscript.m.)

The issue can be reproduced with these three lines of code:

mdl_twolink
cg = CodeGenerator(twolink);
cg.gengravload

It produces the error:

 Assignment has more non-singleton rhs dimensions than non-singleton subscripts

Error in sym/privsubsasgn (line 1040)
                L_tilde2 = builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);

Error in sym/subsasgn (line 877)
            C = privsubsasgn(L,R,inds{:});

Error in SerialLink/rne_dh (line 219)
                tau(p,j) = t;

Error in SerialLink/rne (line 85)
            [varargout{1:nargout}] = rne_dh(robot, varargin{:});

Error in SerialLink/gravload (line 43)
		tg = rne(robot, q, zeros(size(q)), zeros(size(q)));

Error in CodeGenerator/gengravload (line 56)
G = tmpRob.gravload(q);

Error in CodeGenerator/geneverything (line 290)
            [G] = CGen.gengravload;

The source seems to be that in rne_dh.m l. 219 the variable t is a 1x2 vector. A solution is suspected in Link.m l. 516 to 531.

Hi, I am trying to get the symbolic inverse kinematics for a RRR robot but i am getting some errors. Below is the input:

L1 = Revolute('alpha', 0, 'a',1, 'd', 0, 'qlim', [-pi pi]);
L2 = Revolute('alpha', 0, 'a',1, 'd', 0, 'qlim', [-pi pi]);
L3 = Revolute('alpha', 0, 'a',1, 'd', 0, 'qlim', [-pi pi]);
R = SerialLink([L1 L2 L3]);
sol = R.ikine_sym(3);

And the output:

----- solving for joint 1
subs sin/cos q1 for S/C
cant solve this equation
k = 1 2
ans = txcos(q1) + tysin(q1) - 1 == cos(q2) + cos(q2)cos(q3) - sin(q2)sin(q3)
tycos(q1) - txsin(q1) == sin(q2) + cos(q2)*sin(q3) + cos(q3)*sin(q2)

Error using SerialLink/ikine_sym (line 191)
cant solve

Error in closedform (line 17)
sol = R.ikine_sym(3);

Reported by baxter.irt, Jul 28, 2014
What steps will reproduce the problem?

1. create robot model (for example stanford manipulator or baxter robot model from https://groups.google.com/a/rethinkrobotics.com/forum/#!mydiscussions/brr-users/5X1-6w-Ja1I)
   mdl_stanford
2. calculate inertia matrix without base transformation
   stanf.base = eye(4);
   M1 = stanf.inertia(qz)
3. calculate inertia matrix with abitrary different base transformation
   stanf.base = trotz(pi/2)*transl([1;2;3]);
   M2 = stanf.inertia(qz)

What is the expected output?
Expected: The inertia matrix should stay the same
What do you see instead?
Output: Inertia matrix changes with base transformation matrix
M1-M2

What version of the product are you using? On what operating system?
Robotics Toolbox 9.9; Linux 64 bit; Should not matter here

Please provide any additional information below.

In rne_dh.m, Line 122 (https://code.google.com/p/matlab-toolboxes-robotics-vision/source/browse/matlab/robot/trunk/@SerialLink/rne_dh.m?r=751#112), the base transformation is added to the vector from the first joint frame to the second joint frame (pstar). By doing this, the lever arm is not calculated for the first joint but for the point [0;0;0]. By removing this line, the problem seems solved.

Please contact me, if this is not a bug and I missed something
Regards,

Moritz Schappler,
[email protected]
Research Assistant at the Institute for Automatic Control, Leibniz Universität Hannover, Germany

When I run the example in 7.4.2 for determining the Dh factors, i met the error

Attempt to execute SCRIPT DHFactor as a function:
D:\Program Files\MATLAB\R2013a\toolbox\rvctools\robot\DHFactor.m

my command is

s = 'Tz(L1) Rz(q1) Ry(q2) Ty(L2) Tz(L3) Ry(q3) Tx(L4) Ty(L5) Tz(L6) Rz(q4) Ry(q5) Rz(q6)'
dh = DHFactor(s)

Is anyone else met this error and how to deal with it？

Hi,

thank you for a fantastic toolbox. It saved my Master thesis!
While trying out robot trajectories I found an error which has an error message that doesn't really give any information about the source of the error.

Code example:

clear all;
mdl_puma560;
steps = 23;
T1=SE3(0.4,0.2,0)*SE3.Rx(pi);
T2=SE3(0.4,-0.2,0)*SE3.Rx(pi);
s = tpoly(0, 1, steps);
Ts=ctraj(T1,T2, s);

I found that the error:

Error using SE3/interp (line 437)
error in trinterp
Error in SE3/ctraj (line 474)
traj(i) = T0.interp(T1, s(i));
Error in untitled4 (line 13)
Ts=ctraj(T1,T2, s);

Shows up as soon as steps is less than 23.

Best regards
Peter Eriksson

To use the ARTE 3D models, need to make the DH parameters consistent between RTB and ARTE. Worth doing for the robots listed above. Maybe use ARTE kinematic models to create more RTB mdl_ files.

Probably bug in SerialLink.plot3d for prismatic joints.

I have trouble in connecting the two arms, can you please help me with this. I recently saw a paper " dual arm robot control based on navigation function with prescribed performance guarantees" in which they connected two arms using DH parameters mentioned in that paper

. Please teach me what command to use to connect two arms and how?. I am looking forward to hear from you

When using the Simulink blocks with the mex compiled fast RNE, the error S-function 'slaccel', flag = 3 (output), at time 0.0. frne: gravity vector expected pops up.
I tracked the bug down to accel.m, where the rne call should be changed from M = rne(robot, ones(n,1)*q, zeros(n,n), eye(n), 'gravity', [0 0 0]); to M = rne(robot, ones(n,1)*q, zeros(n,n), eye(n), [0 0 0]); to work with Simulink. It seems, that the mex version of RNE is not able to process the parameter name.
Edit: I just realized that inertia.m faces the same issue.

Calling the function
rpy2tr(0.6,0.8,1.4)
returns the wrong rotation matrix. In particular, it calls the function rpy2r, that respectively calls rotx, roty, rotz, that use the sind and cosd functions that assume the angles in degrees. I fixed this problem by changing the conversion in radiants as a conversion in degrees.

Look at possibility of wrapping open rave. Maybe the IK functions

Hi, I'm trying to use the DStarPO algorithm. Everything works woderfully until I call the "path" method with ds.path(start) as done in the example. Whenever I try this, I get an error saying that the "path" method doesn't exist. I read through the code in both DStarPO and other related files and can't seem to find where "path" is. Would it be possible to give me some direction as to where I can find "path", and how I can implement it?

Vehicle class is currently bicycle model.

Should have abstact superclass Vehicle with subclasses Bicycle, DiffDrive etc

Should not effect EKF or ParticleFilter classes.

If I declared the limits of the prismatic articulation, why do I have to declare the limits of the workspace?

Unify ETS.m with ETS3.m

I'm using Matlab R2018b, RTB10.3
I try to use simulink to visualize the movement.

The four blocks from left to right are mstraj, xyz2T, ikine and plot.
Then an error occurs like this:

I'm sure the problem happens due to ikine block because I visualize the movement without simulink correctly. Then I look inside the ikine block, I find it looks like this:

I change it like this and everything works fine. (I haven't used Matlab before, I'm learning it just for a few days so I'm not sure whether this is a feature or a bug.) Is there any solutions that I don't need to change the rolocks.slx?

trail option, doesn't draw any line

plot one robot in two windows, second one fails in animate()

add method to return graphical joint angles

Reported by sarim.utoledo, Oct 3, 2014
What steps will reproduce the problem?

1. Connect the EV3 brick by USB
2. Run the command: gyrorate = b.inputReadSI(0,Device.Port2,Device.GyroRate);
3. The value is NaN. Doesn't matter if the robot is moving or not, it is always NaN. It also tends to reset the Gyro Angle every time it runs.

What is the expected output? What do you see instead?
The command should give the value of the gyro rate. If stationary, it should give zero. But it always gives NaN.

What version of the product are you using? On what operating system?
I am using QUT EV3 MATLAB toolkit, current version on Windows 7 64 bit with MATLAB R2013a. Other functions seem to work fine.

Please provide any additional information below.

Oct 3, 2014 Delete comment #1 sarim.utoledo
Just to make it clear, I have checked the connections etc. The Device.GyroAng works fine, so I am sure Gyro sensor is connected to the port I am using there.

I'm doing the 3D design of a cylindrical robotic arm and I want to import the CAD to Matlab to work with plot3d. What requirements should the * .stl files have to be able to visualize the arm in Matlab?
How can I do it?

When I use RIB10.1 to plot my robot, there is an error：

Prismatic joint(s) present: requires the 'workspace' option

I know it 's because there is a prismatic joint in my robot, but when I add workspace option the error still exists. At last I return back to RTB9.10 and excute the code, there is no bug this time. And I refer to the manual it's not included in the incompatible changes. So I think maybe it's a bug in the new version.
My code lists as below.
L(1) = Link([0,0.363,0.300,0,0],'standard');
L(2) = Link([0,0,0.260,pi,0],'standard');
L(3) = Link([0,0,0,0,1],'standard');
L(3).qlim = [0,0.3];
L(4) = Link([0,0,0,0,0],'standard');
RobotArm = SerialLink(L,'name','SCARA')
RobotArm.plot([0 0 0 0],'workspace',[-1 1 -1 1 -1 1])

The effect of RTB9.10

What could be the cause of this error?
I am trying to generate a trajectory to move the manipulator.