# Basic Arm Kinematics **URL:** https://get-help.theconstruct.ai/c/course-support/basic-arm-kinematics/53.md [Latest](https://get-help.theconstruct.ai/latest.md) · [Categories](https://get-help.theconstruct.ai/categories.md) · [Tags](https://get-help.theconstruct.ai/tags.md) --- ## [About the Basic Arm Kinematics category](https://get-help.theconstruct.ai/t/about-the-basic-arm-kinematics-category/5478)
**Author:** [@bayodesegun](https://get-help.theconstruct.ai/u/bayodesegun)\ **Replies:** 0\ **Last updated:** [September 28, 2020, 11:46am UTC](https://get-help.theconstruct.ai/t/about-the-basic-arm-kinematics-category/5478 "2020-09-28T11:46:39Z")
This category is for questions and discussions related to the Basic Arm Kinematics course. Before posting a new question, please use the search button to see if a similar topic already exists. --- ## [Equation does not conform to Simple SOH CAH TOA definition](https://get-help.theconstruct.ai/t/equation-does-not-conform-to-simple-soh-cah-toa-definition/21556)
**Author:** [@mxenya](https://get-help.theconstruct.ai/u/mxenya)\ **Replies:** 3\ **Last updated:** [January 23, 2023, 9:09am UTC](https://get-help.theconstruct.ai/t/equation-does-not-conform-to-simple-soh-cah-toa-definition/21556 "2023-01-23T09:09:43Z")
From the Simple SOH CAH TOA definition, this is not right. Kindly advise. --- ## [Rigid body basics - incorrect trig equations?](https://get-help.theconstruct.ai/t/rigid-body-basics-incorrect-trig-equations/21558)
**Author:** [@mxenya](https://get-help.theconstruct.ai/u/mxenya)\ **Replies:** 1\ **Last updated:** [January 12, 2023, 9:25am UTC](https://get-help.theconstruct.ai/t/rigid-body-basics-incorrect-trig-equations/21558 "2023-01-12T09:25:04Z")
I think the trig equations for the alpha angle on y-axis are incorrect. --- ## [Rigid body basics - Question about DETERMINANT](https://get-help.theconstruct.ai/t/rigid-body-basics-question-about-determinant/21557)
**Author:** [@mxenya](https://get-help.theconstruct.ai/u/mxenya)\ **Replies:** 1\ **Last updated:** [January 11, 2023, 11:53am UTC](https://get-help.theconstruct.ai/t/rigid-body-basics-question-about-determinant/21557 "2023-01-11T11:53:04Z")
Given that DETERMINANT represents the degree of DEFORMATION of SPACE, is this statement “One last property of the Rigid Body Rotation Matrix is that the DETERMINANT has to be 0 ALWAYS.” right? --- ## [Unit 6: Project](https://get-help.theconstruct.ai/t/unit-6-project/18926)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [August 31, 2022, 2:02pm UTC](https://get-help.theconstruct.ai/t/unit-6-project/18926 "2022-08-31T14:02:30Z")
Hello! I am working on project of ur3 arm kinematics, the part 3 of FK and IK is not clear. Although solution is given but nothing happens after running the file, no error but no output…I tried to print values of varia… --- ## [Unit2 Basic Arm kinematics](https://get-help.theconstruct.ai/t/unit2-basic-arm-kinematics/18626)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [August 16, 2022, 11:38am UTC](https://get-help.theconstruct.ai/t/unit2-basic-arm-kinematics/18626 "2022-08-16T11:38:18Z")
Hello! My Question is related to python file of Unit2 rotations\_conversion.py, why took offset in it as 1 and -1: Code: q\_x = quaternion\_about\_axis(0, (1,0,0)) if roll\>=0: roll\_range = range(0,roll,1) offset = 1 e… --- ## [Unit 6 Project Baisc Arm Kinematics](https://get-help.theconstruct.ai/t/unit-6-project-baisc-arm-kinematics/18727)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [August 16, 2022, 11:37am UTC](https://get-help.theconstruct.ai/t/unit-6-project-baisc-arm-kinematics/18727 "2022-08-16T11:37:28Z")
Hello! In the Given project of Ur3, from the dh table, create transformation matrix general as given in solution? if yes the T3\_4 matrix is showing d3 while it is zero in dh table? iimage attached Dh values… --- ## [Unit3: Forward Kinematics exercise 3.4](https://get-help.theconstruct.ai/t/unit3-forward-kinematics-exercise-3-4/18726)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 1\ **Last updated:** [August 16, 2022, 7:52am UTC](https://get-help.theconstruct.ai/t/unit3-forward-kinematics-exercise-3-4/18726 "2022-08-16T07:52:45Z")
Hello! In Forward kinematics Unit, ecxercise 3.4, tb\_1.py, after executing getting the required result, but in next para it is told that for nice appearing we replace theta\_1 to its symbol θ1, but i am getting this … --- ## [Basic Arm Kinematics Unit3 Forward Kinematics](https://get-help.theconstruct.ai/t/basic-arm-kinematics-unit3-forward-kinematics/18428)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 4\ **Last updated:** [August 4, 2022, 3:23pm UTC](https://get-help.theconstruct.ai/t/basic-arm-kinematics-unit3-forward-kinematics/18428 "2022-08-04T15:23:43Z")
Hello! DH parameters (alpha i, a i, theta i, d i) have same meaning as (alpha i-1, a i-1, theta i, di)? some books uses first notation, i is actually no of joints…kindly clarify this. 2ndly in DH table given the value… --- ## [Unit 2, section 2.1.4](https://get-help.theconstruct.ai/t/unit-2-section-2-1-4/18379)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [July 31, 2022, 12:19pm UTC](https://get-help.theconstruct.ai/t/unit-2-section-2-1-4/18379 "2022-07-31T12:19:43Z")
Hello! Why angle here is taken theta/2? image attached --- ## [Unit 3: basic arm kinematics](https://get-help.theconstruct.ai/t/unit-3-basic-arm-kinematics/18371)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [July 31, 2022, 12:18pm UTC](https://get-help.theconstruct.ai/t/unit-3-basic-arm-kinematics/18371 "2022-07-31T12:18:43Z")
Hello! The kinematic diagram and frame assignment is not clear told in Unit 3(Forward Kinematics), Can someone pls help. Thanks --- ## [Unit 2, 2.1.5 Composition of rotations](https://get-help.theconstruct.ai/t/unit-2-2-1-5-composition-of-rotations/18381)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [July 31, 2022, 12:16pm UTC](https://get-help.theconstruct.ai/t/unit-2-2-1-5-composition-of-rotations/18381 "2022-07-31T12:16:51Z")
Hello! can someone xplain these two points? If we post-multiply, the Z rotation is intrinsic, it is applied to the current coordinate frame (the can rotates about the axis of the cylinder). If we pre -multiply, the Z … --- ## [Sympy package missing](https://get-help.theconstruct.ai/t/sympy-package-missing/14818)
**Author:** [@tuf01133](https://get-help.theconstruct.ai/u/tuf01133)\ **Replies:** 5\ **Last updated:** [July 23, 2022, 8:04am UTC](https://get-help.theconstruct.ai/t/sympy-package-missing/14818 "2022-07-23T08:04:56Z")
I need to do a pip install of sympy in order to run the sample code. Preinstalling the package or adding this to the documentation would be helpful. Thanks! --- ## [IDE not loading for course basic Arm kinematics](https://get-help.theconstruct.ai/t/ide-not-loading-for-course-basic-arm-kinematics/18237)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 1\ **Last updated:** [July 18, 2022, 8:21am UTC](https://get-help.theconstruct.ai/t/ide-not-loading-for-course-basic-arm-kinematics/18237 "2022-07-18T08:21:50Z")
IDE has not been loading for last two hours. Anyone has facing the same problem. Thanks --- ## [Joint controller GUI failing to control arm in exercise 2.1](https://get-help.theconstruct.ai/t/joint-controller-gui-failing-to-control-arm-in-exercise-2-1/12368)
**Author:** [@daniel.v.molina1](https://get-help.theconstruct.ai/u/daniel.v.molina1)\ **Replies:** 3\ **Last updated:** [July 16, 2022, 6:24am UTC](https://get-help.theconstruct.ai/t/joint-controller-gui-failing-to-control-arm-in-exercise-2-1/12368 "2022-07-16T06:24:56Z")
I’ve been trying to run the node that enables controlling the arm in exercise 2.1, however, it keeps failing as soon as I enable sending commands using the rqt\_joint\_trajectory\_contoller gui. I would like to use this fea… --- ## [Unit2\_positions.py,, Unit 2 Basic Arm Kinematics](https://get-help.theconstruct.ai/t/unit2-positions-py-unit-2-basic-arm-kinematics/18141)
**Author:** [@misbahsuhail123](https://get-help.theconstruct.ai/u/misbahsuhail123)\ **Replies:** 2\ **Last updated:** [July 16, 2022, 5:35am UTC](https://get-help.theconstruct.ai/t/unit2-positions-py-unit-2-basic-arm-kinematics/18141 "2022-07-16T05:35:14Z")
unit2\_positions.py utilities file is missing, kindly share it… i am getting this error --- ## [Course Project Basic Arm Kinematics](https://get-help.theconstruct.ai/t/course-project-basic-arm-kinematics/16720)
**Author:** [@kevinnoventa](https://get-help.theconstruct.ai/u/kevinnoventa)\ **Replies:** 1\ **Last updated:** [April 22, 2022, 9:44am UTC](https://get-help.theconstruct.ai/t/course-project-basic-arm-kinematics/16720 "2022-04-22T09:44:44Z")
Hi, I wanna ask about this course project Part I & PartII : I still don’t really understand about the assignment. So I need to generate the program for transformation matrix in python? --- ## [Clarkson\_Manipulator URDF Missing](https://get-help.theconstruct.ai/t/clarkson-manipulator-urdf-missing/6976)
**Author:** [@brandon.m.lutz](https://get-help.theconstruct.ai/u/brandon.m.lutz)\ **Replies:** 4\ **Last updated:** [January 24, 2022, 9:25am UTC](https://get-help.theconstruct.ai/t/clarkson-manipulator-urdf-missing/6976 "2022-01-24T09:25:01Z")
The below command is not working for me to copy the urdf for the Clarkson\_Manipulator. The below path does not exist in my environment. Please let me know if there is another path that I should be using. This is at the e… --- ## [1.2 Exercise does not load properly](https://get-help.theconstruct.ai/t/1-2-exercise-does-not-load-properly/13882)
**Author:** [@johnnovak](https://get-help.theconstruct.ai/u/johnnovak)\ **Replies:** 2\ **Last updated:** [November 24, 2021, 6:06pm UTC](https://get-help.theconstruct.ai/t/1-2-exercise-does-not-load-properly/13882 "2021-11-24T18:06:54Z")
running roslaunch assem\_moveit\_config assem\_planning\_execution.launch does not display the rviz motion planning panel. Logged out/in, restarted exercise several times, same result --- ## [Rosrun joint\_trajectory\_controller joint\_trajectory\_controller](https://get-help.theconstruct.ai/t/rosrun-joint-trajectory-controller-joint-trajectory-controller/8289)
**Author:** [@Arnolvalencia1](https://get-help.theconstruct.ai/u/Arnolvalencia1)\ **Replies:** 2\ **Last updated:** [February 17, 2021, 9:44pm UTC](https://get-help.theconstruct.ai/t/rosrun-joint-trajectory-controller-joint-trajectory-controller/8289 "2021-02-17T21:44:53Z")
Goodnight. I am following the course faithfully, in lesson two it asks me to write the following code in the console: $ rosrun joint\_trajectory\_controller joint\_trajectory\_controller But I get the following error mess… --- ## [Kinematic solvers](https://get-help.theconstruct.ai/t/kinematic-solvers/5876)
**Author:** [@LucasReyBraga](https://get-help.theconstruct.ai/u/LucasReyBraga)\ **Replies:** 4\ **Last updated:** [October 29, 2020, 1:04pm UTC](https://get-help.theconstruct.ai/t/kinematic-solvers/5876 "2020-10-29T13:04:07Z")
Hello, I have some problems related with this course. I understand the course and I think that i have some good experience in working with robotic arms and its kinematics, but I don’t find the relation between creating …