26

Compare the following two images: The path planning is somewhat trivial. There's only one path: the rope. The motion planning on the other hand is not that easy. In a maze the path planning is hard and motion planning is easy: Of course both planning tasks can be easy or hard at the same time or anything in between. They are linked to one another in that ...


7

Yes. As @hauptmech mentioned, you can use your forward kinematics to get the center of mass of each link in the base frame. Then you can simply compute the weighted average of the masses and positions to get the overall center of mass. In other words: $$ M = \sum_{i=0}^n m_i $$ $$ \mathbf{P}_i^0 = pos( \mathbf{T}_i^0(\mathbf{q}) \mathbf{T}_{i_m}^i) $$ $...


6

What's the difference between turn-by-turn GPS and driving a car? GPS is path planning: high-level commands like, "turn right in 1 mile." Driving is motion planning, which means following a route established by path planning while at the same time taking care of the minutia: interfacing with the car, staying in lane, watching for pedestrians, obeying ...


6

better you say ? That's a nice wheeled robot you have there. Can I borrow it for a day? Thanks. Wow, it's really fast, I cannot keep up with it walking or running on the street. Truly an amazing machine. I'd like to show it to my friends and family. They are waiting in my flat that's on the 3rd floor up the stairs...what do you mean it cannot move over ...


4

The Boston Dynamics’ Atlas robot doesn't actually use servo motors. It uses electrically-powered hydraulic actuation. I saw a presentation by Boston Dynamics' Marc Raibert where (if I remember correctly) he said they used to use Moog actuators designed for the aerospace industry, but that they were now using a motor that they build in-house that is ...


3

You need enough domain knowledge to be able to tell if someone is bullshitting you or not, to be able to determine when someone has an achievable or unachievable project idea, to be able to determine who has talent and who doesn't, etc. And money. A lot of money. Quality engineers don't work for free.


3

From another point of view, bipeds(humanoids) are regardless of their use interesting since they are high dimensional nonlinear hybrid systems. Sure, there are more systems with those qualifications, but the special thing with bipeds is that we have a clear intuition of what is right and wrong even without any mathematical background. Furthermore, take a ...


3

That looks like a fun pair of arms :-) Yes, if you already have a known pose, choosing a solution that minimizes movement is a decent choice. The obvious draw-back is that which choice is made for a particular pose then depends on history, which may make validation harder. Another choice would be the one that minimizes the torque (because of gravity/load) ...


3

Keep in mind that the ZMP is a simplification. In practice with walking robots the support polygon is constantly changing so it can be tough to keep the ZMP inside. Pregenerated (offline) trajectories will only work in very specific conditions (flat ground, no disturbances), and only if you can model your support polygon well. That said, everything you ...


3

ROS is good for when you start writing code to run on a PC. It lets you write independent modules that interface through standard messages and service calls. Furthermore, it has a large user base with lots of off-the-shelf tools, drivers, and higher-level behaviors. What ROS is not good for is inter-microcontroller communication. (ROS's communication is ...


3

There isn't really a difference. "Path planning" might be used more often to simply describe the problem of finding a desired path from one state (or sub-set of states) to another. Whereas "motion planning" might be used to describe the same problem but more specifically the actual commanded motions that the robot uses to track the series of desired states ...


2

The "best" robot wrist in terms of human analog is probably the omni-wrist by Mark Rosheim. It has a large range of motion, and does not have singularities or gimbal lock that plague other more conventional wrists. However, it is fairly complicated mechanically, and thoroughly patented i believe. The book Robot Evolution: The Development of Anthrobotics ...


2

Bear in mind a Stewart platform has six degrees of freedom - yes it does reproduce the main motions of the human wrist, but it adds extra ones such as the ability to change its overall length. There is (I would guess) additional complexity in building one - finding suitable compact actuators and linkages, additional work to control its path, perhaps ...


2

The majority of the noise you're hearing is not from the motor itself but from gearing, which both servo motors and drills have a lot of. However, if you don't have a gearbox then when power is cut the torque exherted by the motor will become zero and your arm will fall. I would reccomend a standard brushed DC motor with an encoder for precise control, ...


2

Path planning would essentially be setting out a path on a particular terrain for the robot to navigate, primarily automatically, coupled with the shortest route detection avoiding obstacles. Motion planning could be termed as the the procedure by which you enable your robot to move - which type of sensors to use, what type of wheel to move, automatic or RC,...


2

Just an extract from my answer to a similar question: Path planning is the process you use to construct a path from a starting point to an end point given a full, partial or dynamic map. Motion planning is the process by which you define the set of actions you need to execute to follow the path you planned. I can also add that you can perform ...


2

When it comes to robots the terms that are most often used are path planning and trajectory planning. While motion is most commonly used in combination not with planning but with control as in motion control. In most cases by path planning the spatial aspect of planning is considered, while trajectory planning (again, in most cases) includes the velocity ...


2

Replying to your comment and the robotic hand mentioned in Gizmag, I think I can answer some of your questions, but before I begin, there are some important references that you should consult to really understand the questions that you have asked. The robotic hand in question operates on the "twisted string" principle, which act as tendons in the hand. The ...


2

Humanoid robots balance and motion planning are not trivial tasks. I believe you will learn a lot if you read about Zero Moment Point (ZMP). Basically, it is a specific point of contact between the robot's planar foot and the ground. What makes this point special is that the reaction forces at it produce zero torque on the robot body. If there is no reaction ...


2

You can use differential IK to solve for a set of IK solutions along a given trajectory. The idea is that you use the IK solution of the current time step, to compute an IK solution for the next time step. Suppose $q$ is your IK solution at the current time step and $x^+$ is the desired end-effector pose at the next time step. You may compute $q^+$ by ...


2

Since it is not sure that your robot is in a plane or not, I would consider it in 3D. You have all the geometrical dimensions of the robot. And I assume you have also all angles in all joints. You need to calculate the X Y and Z coordinates of all centers of masses on the image, relative to the same coordinate system. It is important that they are ...


2

This isn't my area of expertise, but it looks like your guess in your question is correct. From the paper: Let $F_{\mbox{targ}}$ denote the target pose of the gripper, and let $F_{\mbox{cur}}(\theta)$ be the current pose. Then $F^{-1}_{\mbox{targ}} F_{\mbox{cur}}(\theta)$ gives the pose error, measured in the frame of the target pose. This pose error ...


1

To create a company of any kind you need both business skills and interpersonal skills. The main domain knowledge should come from your CTO (Chief Technical Officer) and your engineers. Your main job will be to secure funding for the company. If the company is small enough that you are the CTO also, then you need to be able to impress the engineers. You ...


1

If having a company is more important to you than working in robotics for someone else, business skills and people skills are more important than technical skills. Being successful requires experience, acquired over a lot of time with a lot of learning opportunities (failure). It also requires a good network of people you can draw on for knowledge, ...


1

All depends on much "standards" is your robot and how much coding of the simulator you want to code. If you don't want to simulate contact the easiest way is to write down your own simulator in you favorite language, based on the underlying mathematical model of your robot. If you have access to matlab the simmechanics toolbox, can be interesting because ...


1

There is the problem, that human-like robots are not yet able to move as reliably as humans. Not far ago was there content for robots to get out of car, walk to doors, open the handle and walk inside - a lot of participants failed miserably at such "simple" work. There is so much possibilities for movements, lot of inertia, not well defined ground and not ...


1

Whole body control (WBC) refers to how to control antropmorph structure (as a system), while the computed torque control (CTC) is a method to compute the torque in 1 single joint (i.e. to control 1 element in a system). Computed torque control can be used only is you have an (inverse) dynamic model. I cannot comment on the question of using WBC without a ...


1

Based on the figure on pg 27 of the manual, it looks like the EX-106 implements a simple proportional controller, with a deadband when the servo is very close to the goal position. The manual calls the Proportional term "compliance slope" and calls the deadband width "compliance margin." Looks like you can use a different Proportional term in the clockwise ...


1

Vision will typically use as much processing power as you can provide. Large humanoid (human size) control systems also take a lot of processing power. It is common for a large humanoid to have at least two large computers (one for vision, one for control) or more. Also, each motor controller and many sensor subsystems will have microcontrollers. There is ...


1

The correct question is "Will humans ever be able to know everything about themselves?" In order to transfer an exact copy of A to B you first have to have full knowledge about A especially when it comes to things as complex as the way humans live and think. If at some point in the future humans manage to unravel all the mysteries of the human body and mind, ...


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