JSycamore
  • Member for 6 years, 9 months
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Building a stationary robot. ROS the right tool for me?
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If all you want from ROS is the publish/subscribe architecture, then I would caution that using ROS probably has non-negligible overhead, especially if you are unfamiliar with it. In particular, the ...

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Urdf as a way to model dynamics?
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2 votes

No. URDF is a convenient way to format information about the model; it is not a model itself.

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Accessibility distribution of three vector fields
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0 votes

Chow's Theorem states that: The driftless system $$\dot q=g_1(q)u_1+...+g_m(q)u_m$$ is locally controllable at $q_0\in\mathbb{R}^n$ if $\text{rank}\bar\Delta(q_0)=n.$ Here, $\bar\Delta$ is the ...

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holonomic and non holonomic constraints in layman's term
1 votes

A constraint on the $k$ coordinates $r_1,r_2,...,r_k$ is holonomic if it is an equality constraint of the form $$g(r_1,...,r_k)=0,$$ and nonholonomic otherwise. These sorts of constraints arise ...

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Is there any error analysis of Irobot Create 2?
1 votes

Ostensibly, the error in angular and linear velocity of the Create 2 is quite large--this is due in part to limitations of open-loop control of the robot based on motor encoders that introduce ...

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I want to know whether the Create2 can interface a LIDAR?
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1 votes

If you are willing to work at it, adding LIDAR to the Create 2 should be possible. If you read the iRobot Create 2 OI Specs, you will see that you can communicate with the Create via serial ...

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Is it possible to detect road surface or navigation area using LRF data or other laser data in a Park?
1 votes

Is it possible to detect road surface (not grass) using LRF data or other laser sensors? Yes it is possible. A laser scanner will give distance measurements along a scan line. Presumably, the road ...

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How do monocular visual odometry algorithms work?
8 votes

Monocular vision is a difficult and very interesting, particularly in its application to the general navigation problem. I will make an attempt at answering your questions, but if you find anything ...

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What are the specifications of the digital compass used in iPhone 6S
1 votes

Typically, and unsurprisingly, proprietary information (to include part numbers, schematics, etc.) is closely guarded by companies. As such, I am not sure how much information you can expect to ...

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Localising a robot placed at an unknown position in a known environment
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3 votes

The problem is that you can't apply path planning until you know where the robot is in the global coordinate frame. There are many localization techniques, and each has its pros/cons; I have used ...

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what books do you suggest for a beginner like me ?
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2 votes

If you only want a single comprehensive text on Robotics, I would recommend the Springer Handbook of Robotics. I covers everything from controls and artificial intelligence to perception and mechanics;...

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Find object using only distance
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1 votes

There are two challenges that you will have to address. First is localization of the robot relative to the Bluetooth source; second is the controller that will drive the robot to the source. To ...

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What does internal sparking in a motor mean?
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2 votes

If you are using a brushed DC motor, then (hopefully) the sparks that you are seeing are a discharge between the commuter and the brushes--this is normal. Another example of this is evident in certain ...

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Are there any others alternatives for PID controllers for line following robots?
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0 votes

Because you don't have any specific robot in mind, let's assume that you have a two-wheeled differential drive robot (TWDDR). TWDDRs can be modeled with unicycle dynamics of the following form: $$\dot{...

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The 3 key components of a robot are controller, servo, and reducer. Can someone give us an "official" explanation of what they do respectively?
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0 votes

Your question is premised on a misunderstanding of what a robot is composed of, but you are close. A robot is an agent that is capable of sensing, thinking, and acting. The sense-think-act (or sense-...

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Switch activated by a microcontroller
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2 votes

You can use a relay for the switch. Relays typically have 4 pins: 2 are the switch, and the other 2 control the switch. For reed relays, the switch is a small metal reed (normally closed) that makes ...

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Covering Up Ultrasonic Sensor
-1 votes

You should consider building a measurement model for your sensor--this will enable you to use your measurements in an effective probabilistic manner. The problem is that beam sensors are noisy, ...

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What are the prerequisites for learning ROS?
2 votes

To learn and use ROS, you do not need to know anything about Linux kernel development, and at first, you shouldn't need to worry about writing drivers. All you need to know is how to use a command ...

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Using robotic simulator for prediction step in probabilistic localization approaches
1 votes

In the probabilistic approaches that you mentioned, specifically Monte Carlo Localization (MCL), the prediction step is made based on state (pose) information and measurements. MCL relies on the ...

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iRobot Create2: Granularity of drive control?
1 votes

In my brief stint working with the Create 2, I noticed the same thing. Specifying very low velocities doesn't work very well, and small increases don't seem to do anything up to a certain point. This ...

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Detect physical touch/hit
1 votes

One option could be to use the MPU6050 IMU, or some other accelerometer. These sensors are cheap, so they will come in under your budget. With acceleration measurements, you can detect impulses ...

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Arduino or Raspberry Pi?
1 votes

One point that hasn't been addressed, which is admittedly outside the scope of the prompt, is whether or not a Pi should be used at all as the off-board component. Unless you are trying to develop on ...

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"Smooth" inverse kinematics model for 2-wheeled differential drive robot
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If I understand correctly, you would like to understand how control a two-wheeled differential drive robot so that you can achieve smooth/elegant driving while arriving at a desired final orientation--...

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Linearize a non linear system
3 votes

The short answer to this question is that linearization won't work, and here's why: Differential drive robots can be modeled with unicycle dynamics of the form: $$\dot{z}=\left[\begin{matrix}\dot{x}\\...

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What frequency does my quadcopter output-sense-calculate-output update loop need to stay stable?
1 votes

Your question can only be answered specifically if we have the model parameters of your system. The most principled approach to answering your question would be to represent the highly nonlinear ...

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What is a suitable model for two-wheeled robots?
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The answer to this is simple, but the other answers obfuscate the dynamics. Differential drive robots can be modeled with unicycle dynamics of the form: $$\left[\begin{matrix}\dot{x}\\ \dot{y} \\ \...

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Ultrasonic Sensor through a column
0 votes

Is the sensor expected to have error of this order? In brief, yes. All sensors will have some degree of noise, which is characterized by the manufacturer. To avoid this, you can use a different ...

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How to create a model for temperature control?
1 votes

Chuck is right; you need to build a model so that you can appropriately choose your controller. Temperature control is non-trivial because the underlying dynamics are non-linear. Because heat ...

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Measuring vehicle's forward and lateral acceleration using a smartphone
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There are many things to consider. Assuming that you are developing an app to accomplish this, you should invest some time in filtering. Depending on the vehicle and the phone's position in the ...

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Stabilising an inverted pendulum
3 votes

The theory that describes what you are looking for is call Control Theory. Search for the Nonlinear Systems textbook by Hassan Khalil for an excellent overview of the material--the inverted pendulum ...

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