prismatic | declarative JS library for creating 3D content | Frontend Framework library

I am building a two link system. The parent link is a curved object and the second link has a single degree of freedom to follow the curved length. I attempted to implement this with a prismatic joint but I can only define a linear path. How can I model this system in drake?

In my block diagram I insert an Enumeration, call it "jointKind", and give it attributes "revolute", "continuous", "prismatic", "fixed" and "floating". Each attribute is Scope=Public, Stereotype=enum. Except for Name, Scope and Stereotype I left other fields (e.g. Type, Alias, Initial) empty.

I then create a block, called it "Robot", and give it a property. That property is typed by "jointKind". However when I chose an initial value I'm given an empty space to type my value.

I should think that when I choose an initial value then the attributes I previously assigned to the enumeration are mad available for me to chose from.

How to enforce enumerations on properties typed by Enumeration?

I am a newbie to HTML, CSS and JavaScript and I learned just enough to make a startpage. I have a search bar which toggles between two different search engines when an image element(here it's the logo of the search engine) on the side is clicked and also switches the image element to match the new state. Here's the JavaScript code:

I have started to write some classes to compute the transformation along a kinematic chain. I'm having a templated parent class KinematicChainSegment and multiple specialized implementations of it (e.g. for revolute or prismatic joints). To give a concrete, minimum example - this how I would like it to look:

I'm trying to find contact Jacobian defined as M(q) q_ddot + C(q, q_dot) = G(q) + B(q) u + J'(q) lambda.

I tried to mirror the function CalcNormalAndTangentContactJacobians() as in multibody_plant.cclink but the values are not adding up.

Here is how I setup the system (for the simplest setup possible):

I have a cylinder mounted to world through a revolute joint and a ball that can freely move in the x-y plant through dummy prismatic joints. I run the simulation that drives the joint at constant torque to make contact with the ball and push it off. I log the states of the system through simulation and find an instance when there is contact and look at that particular instance.

I set the MultibodyPlant(MBP) to the states as exactly in the simulation by SetPositionsAndVelocities and SetActuationInArray, and get the relative variables M, Cv, tauG, B, q_ddot, tauExt, and contactResults.

Now I'm ready to find the contact Jacobian. (Updated in reflection to the two suggestions from @Alejandro)

In using a multibody plant (MBP) for estabilishing dynamics constraints for multibody system with contact, we look at the dynamics equation

M(q) q_ddot + C(q, q_dot) = G(q) + B(q) u + J'(q) lambda

where q is the states of the system, *_dot and *_ddot denotes *'s time derivative and double derivative, respectively; M(q) is the inertial matrix, C(q, q_dot) consists of the terms for Coriolis, centripetal, and gyroscopic effect, G(q) is the gravitational force, B(q) is the actuator matrix, u is the input (torque/force), J'(q) is the contact Jacobian transposed, and lambda is the contact force in the contact frame.

is there a way to get the contact Jacobian terms J(q) from the plant or is it up for the users to implement it with the contact results?

Question Update:

I've been trying to verify the returned results from hand-derived Jacobian and there is some mis-matching that I don't understand.

First, I constructed a very simple system: a link fixed to world through a revolute joint and a sphere that can roll in the x-y plane through dummy prismatic joints. The link is named left proximal. The contact Jacobian is easy to derive by hand with contact point returned from contactResults using which, the contact dynamics is verified.

Now, here is how I find contact jacobian from drake functions:

I am not able to run "lein ring uberjar" from my local machine. I get the following errors:

I am writing the following code which specified the attribute must return it even if it is of type obj, array, string or number.

I'm having some problems getting me back certain attributes going even deeper.

I would like to do this without using external modules.

Can you give me some advice?

I am pulling a variable string Rarity from an API.

I then need to shorten this string depending on what I receive. So I am using a big if/else block: