# Tag Info

Accepted

### How can I use an RC servo to rotate more than 360 deg and still maintain positional accuracy?

While originally creating this question I ended up finding an RC servo that can do this. HiTECH makes an RC servo (HS-785HB) that uses a muti-turn potentiometer rather than a standard rotary ...
• 725
Accepted

### How do I find the inverse kinematics of a 5-DOF manipulator having the following DH parameters?

A general IK solution is not possible for an arm with less than 6 joints. You can move the gripper to any point (within reach) but you can't completely control the orientation. If you fix the ...
• 1,702

### How do I find the inverse kinematics of a 5-DOF manipulator having the following DH parameters?

If you say you're are stuck after values for the first two angles, you are probably trying an analytical approach. Try solving for IK using standard techniques Jacobian Pseudo Inverse or Cyclic ...
• 671
Accepted

### Definition of robotics manipulator?

The original manipulators referred to in that article were through-the-wall pantographs which moved radioactive materials without the human operator having direct contact with those materials. The ...
• 4,396
Accepted

### What does it actually mean by Task Planning?

I think what you are seeing here is a decade advancement in microprocessor and robotic control technologies. By the time the second and third papers were written, in 2000 & 1998, the definition ...
• 4,263
Accepted

### Is there a Java or mathematical algorithm for Pure Path Pursuit?

In words, rather than code. Assume you have the path defined as a dense list of points. Find the point on the path closest to robot Draw a circle of radius R about that point, then find the point on ...
• 1,702

### Matlab Simulation using Webots!

You've got two serious problems clearly stated in your error message: Warning: Name is nonexistent or not a directory: C:\Program Files\Webots\lib\matlab And The MATLAB "MinGW-w64 C/C++ ...
• 16k
Accepted

### Robots with less than 6 degrees of freedom

Short answer: No. Long answer: In how many dimensions you are defining 'any'? The best way to understand it is actually through math. Let's say you have a desired position p=\left[\begin{matrix}x\...
• 103

### Can you detect if encoder wire is connected on a motor?

If you have a situation where your motor can break your system, for a small DC motor then rather than relying on a solution which requires the software to detect the condition, instead add limit ...
• 531
Accepted

### why atleast three points are needed to control 6 dof?

We need to be able to track 3 points, (sometimes called features), on a solid body to estimate its 6dof pose relative to the camera. Each has an estimated position in the 2D camera image. If you ...
• 4,445

### Is there a more accurate feedback loop with less overshoot or disturbances than PID?

You might want to try a Non linear controller if you want disturbance rejection. But I will suggest you to fine tune your PID first. Now, back to non linear controls, you need to develop a very good ...
• 163

I believe you should start from below and up. First, validate the inverse kinematics for the 4 legs you build. Remember that small mistakes accumulate over time, so it's best to ensure minimum error ...

First of all, I would implement a simple gait type with static stability. It is the easiest to implement and if you have already figured out the leg inverse kinematics it should bring fast results. ...
• 6,682
Accepted

### Beginner Sets for intermediate devs

If you want to start programming a robot that's already built, the Scribbler 3 (S3) robot by Parallax, inc. is relatively affordable and comes already assembled. The programming relies on Blockly, a ...
• 46
Accepted

### What is the concepts of submaps in LIDAR based graph slam algorithms?

The word is exactly as it sounds. It is a submap of a larger map. Essentially a large map is broken up into smaller submaps in order to improve the computational complexity. In the reference you ...
• 1,881

### Low power to motors -- motor power jumper issue

I had the same problem with the "Ultimate 4tronix Initio 4WD Robot Kit" - the motors make some noise, but do not start moving. I tried using 8 batteries instead of 6 (for higher voltage on the motor), ...

### Controller Design using Webots!

Since you already have controller code written for the physical robot, I recommend creating a set of adapters so you can run the same code in Webots, instead of rewriting everything from scratch. The ...
• 1,363

### How can I allow for this code to switch from remote control to autonomous?

The code for “task autonomous()” should be outside of the main() function.
• 4,396

### How to calculate potential enegy of manipulator dynamics?

We have the position of the COM of the $i_{th}$ link with respect to the $(i-1)_{th}$ frame (or joint). Also, the homogeneous transformation matrix relating the $(i-1)_{th}$ frame to the $0_{th}$ ...
• 31

### Conversion of roll, pitch and yaw from ENU to NED

ENU = East, North, Up NED = North, East, Down So, if you have x_ENU, y_ENU, and z_ENU, then: ...
• 16k
1 vote

### Need Suggestions for real-time number or object detection with Arduino + MATLAB?

If you want to do some basic obstacle detection with an arduino your best bet is either using an ultrasonic sensor or a LIDAR. Image processing is likely to be too complex for an arduino that is also ...
1 vote

### How to determine x-axis if the two z-axis are parallel in Denavit Hartenberg representation

Make them parallel to the previous X Axis. This helps reducing the number of non-zero coordinates in the DH table which in turn means less + and * operations in the calculations.
• 6,682
1 vote

### Is there a Java or mathematical algorithm for Pure Path Pursuit?

Here's an example implementation in Java for FRC: https://github.com/Team488/SeriouslyCommonLib/blob/master/src/main/java/xbot/common/subsystems/drive/PurePursuitCommand.java Let us know if we can ...
1 vote

### How to proceed whith this design problem?

1) StackExchange is really not intended for the side-by-side mentoring it seems you are looking for. It is a good place to ask questions about specific problems you run into. 2) Python is not the ...
• 725
1 vote

### Flight controller drift issue

You are using cheap MEMS components, they are typically prone to noise and drift. I don't know how you retrieve your angles but the sensors are giving you angular velocities and linear accelerations. ...
• 1,412
1 vote
Accepted

### How to get starting location of robot using IMU Sensor (without using gps)

An IMU gives you linear acceleration and rotational speed. It doesn't give a position. You can integrate the output of an IMU to get a linear position and angular orientation (the pose), but you ...
• 16k
1 vote

### How to keep track of (x,y) co-ordinates of a line-following bot?

Keeping tracking of (x,y) location would fall under state estimation. One fundamental method of state estimation is odometry.
• 71
1 vote

### First steps in robotics

Answering for others with the same question... I understand the OP has long since moved on I don't disagree with the others here, but have a different take. Direct answers to your questions (with an ...
1 vote

### First steps in robotics

I agree with what @PrestonRoy regarding the academic aspects. But, there is a big learning by doing component too. The earlier you start the better. Don't wait until you "know everything you ...
• 725
1 vote

### First steps in robotics

I am a graduate student whose research is applied to robotics. I recommend: Linear algebra and Calculus Basic programming skills, learn arduino and another language Electronics courses - basic ...
• 181

Only top scored, non community-wiki answers of a minimum length are eligible