Questions tagged [mobile-robot]

A robot which is capable of moving from one place to another, usually of its own volition.

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74
votes
4answers
12k views

Why are Mars rovers so slow?

Mars rovers are typically very slow. Curiosity, for example, has average speed of about 30 meters per hour. Why is it designed so slow? Is it because of some specific power restrictions or for other ...
30
votes
3answers
7k views

What is a suitable model for two-wheeled robots?

What is a suitable model for two-wheeled robots? That is, what equations of motion describe the dynamics of a two-wheeled robot. Model of varying fidelity are welcome. This includes non-linear models,...
27
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5answers
54k views

Which type of actuator will be suitable for a very strong robot arm

I wish to build a robotic arm that can lift a useful amount of weight (such as 3-6kg on an arm that can extend to approx 1.25 meters). What actuators are available to accomplish this. The main factors ...
25
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6answers
23k views

What algorithm should I implement to program a room cleaning robot?

For this question assume that the following things are unknown: The size and shape of the room The location of the robot The presence of any obstacles Also assume that the following things are ...
23
votes
4answers
13k views

How should emergency stops be wired?

Emergency stops are obviously a good idea on most robots, how should they be wired? What systems should be killed immediately, and what should stay working?
17
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3answers
2k views

Why do Mars rovers designers prefer wheels over tracks?

Typically Mars rovers use wheels and not tracks. I guess Spirit would have better chances getting out of that soft soil should it have tracks. In general, Mars surface structure is not known in ...
16
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2answers
18k views

Wheels vs Continuous Tracks (Tank Treads)

I'm building a small robot using some cheap Vex Robotics tank treads. However, my choice of picking tank treads is almost purely based on the fact that they seem like more fun than wheels. I don't ...
15
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6answers
7k views

What is the difference between path planning and motion planning?

What are the main differences between motion planning and path planning? Imagine that the objective of the algorithm is to find a path between the humanoid soccer playing robot and the ball which ...
14
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2answers
12k views

Calculate position of differential drive robot

How do you calculate or update the position of a differential drive robot with incremental sensors? There is one incremental sensor attatched to each of the two differential wheels. Both sensors ...
13
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3answers
4k views

Do “nano bots” (that can fit inside the human body) actually exist?

I was wondering, do we have real nano bots, like the ones in the movies? I think we have bots which can move through the blood vessels, am I right?
12
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5answers
1k views

What are the reasons for not having autonomous robots in our daily activities?

The fact is that the more I search the less I find autonomous (real) robots in use. The companion robots are all toys with limited useless functionality. Whenever there is a natural disaster you don’t ...
12
votes
2answers
907 views

Is it better to have weight distributed over the wheels or the center of the robot?

When designing a standard 4 or 6 wheel robot, is it better to have the weight distributed primarily in the center of the robot, or over the wheels, or is there no difference? Specifically, which ...
12
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1answer
1k views

How to get two continuous tracks (tank treads) to move at the same rate?

I've got a couple Vex 269 Motors hooked up to an Arduino Duemilanove. These motors run a some Vex Tank Treads. The two motors are run as servos on the Arduino using the Servo Library. The problem I'm ...
12
votes
3answers
8k views

Calculating the efficiency of Mecanum wheels

I'm part of a FIRST Robotics team, and we're looking into using Mecanum wheels for our robot. What are the advantages and disadvantages of using Mecanum wheel versus regular ones? From looking ...
12
votes
2answers
3k views

Differences between Ackermann steering and standard bi/tricycles concerning kinematics?

I got the following homework question: What are the general differences between robots with Ackermann steering and standard bicycles or tricycles concerning the kinematics? But, I don't see what ...
12
votes
1answer
2k views

What is a good approach to a Quadruped Gait?

I have a small quadruped with three degree of freedom legs which I have been working on: 3DOF Mini Quadruped. My original code for it was a simple servo controller on the arduino, and Scala code ...
11
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2answers
3k views

Correct way to use Subsumption Architecture with Robot C

I've been doing a lot of reading lately about Subsumption Architecture and there are a few different ways people seem to advocate. For instance some people use a global "flag" variable to have a ...
11
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1answer
2k views

How can the dynamic effects of motor current on a digital compass be characterized and compensated for?

Digital compasses (magnetometers) require a hard/soft iron calibration in order to be accurate. This compensates for the magnetic disturbances caused by nearby metal objects -- the robot's chassis. (...
10
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5answers
4k views

Seeking dirt cheap, wheeled, programmable robot

I was playing the old "confuse the cat with a flash-light" game, when I thought that I might like to program a confuse-a-cat robot. Something, probably with tracks, which can right itself if he flips ...
10
votes
2answers
1k views

Sonar for obstacle avoidance: how many sensors and where to place them?

For avoiding obstacles during 2D robot navigation what is the best position/angle to place the sonar sensors? How many should there be? I would like to know if there is some theory or examples for ...
10
votes
1answer
2k views

Why should I still use EKF instead of UKF?

The Unscented Kalman Filter is a variant of the Extended Kalman Filter which uses a different linearization relying on transforming a set of "Sigma Points" instead of first-order Taylor series ...
10
votes
4answers
6k views

How to make an “invisible line following robot”?

I would like to build a robot which follows a virtual path (Not a visible path like a 'black line on a white surface', etc). I'm just enthusiastic by seeing some sci-fi videos which show robots carry ...
9
votes
4answers
3k views

What are human-friendly terms for mobile-robot orientation and relative direction of non-robot objects?

Within robotics programming, orientation is primarily given in terms of x, y, & z coordinates, from some central location. However x, y, z coordinates aren't convenient for rapid human ...
9
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2answers
3k views

Shape Memory Alloy wire for robot gripper arm actuation: How to vary grip pressure?

For a robotic gripper arm we are designing for factory floor use on very small components, we propose to use electrically activated Shape Memory Alloy (SMA) wire harnesses for actuation. The device ...
9
votes
3answers
2k views

Quadruped Learning Simulator

I'm currently building a robot with four legs (quadruped), 3 DOF (Degrees of Freedom) and Its been suggested here that I use a simulator to do the learning on a computer and then upload the algorithms ...
9
votes
2answers
1k views

Extended Kalman Filter with Laser Scan + Known Map

I am currently working on a project for school where I need to implement an extended Kalman Filter for a point robot with a laser scanner. The Robot can rotate with 0 degree turn radius and drive ...
9
votes
2answers
183 views

Robotics Location Following and Tracking?

I am building a robot that will follow a target as the target moves around. I would like some help with the setup for tracking the target. The most obvious solutions are Ultrasound or Infrared sensors,...
8
votes
2answers
712 views

Are power and torque required related in some way?

I am designing a new platform for outdoor robotics and I need to calculate the power and/or torque that is needed to move the platform. I have calculated that I need about 720 W of total power to move ...
8
votes
3answers
2k views

SLAM without landmarks?

First, is it possible to build map without landmarks for a robot in 2D? Let's say we have an aisle surrounded by two walls. The robot moves in this environment. Now is it feasible to build such a ...
8
votes
1answer
574 views

Building a balancing robot with differential drive

I've already built a two wheeled balancing robot using some continuous rotation servos and an accelerometer/gyroscope. I upgraded the servos to some geared DC motors with 8-bit encoders with the goal ...
8
votes
5answers
1k views

Strategies for managing power on electrical systems for mobile robots

What are some good strategies to follow while designing power supply for electrical systems on mobile robots? Such robots typically comprise of systems with microprocessor, microcontroller, DSP, etc ...
8
votes
1answer
485 views

Are time-of-flight cameras like the swissranger affected by outdoor fog?

I'm looking to build an outdoor robot and I need to know if time-of-flight cameras like the SwissRanger™ SR4500 work in fog, does anybody have some experiences on that?
7
votes
4answers
918 views

What is the technical name when robot wheels are aligned to perform spot turn?

I have a robotic simulator that enables a 6 wheel rover to perform spot turn. To prepare the rover to spot turn, I have to arrange/align the wheels in such a fashion: ...
7
votes
3answers
2k views

Fastest maze algorithm for robot

I'm planning on programming a prebuilt robot to solve a maze as fast as possible. The robot has forward obstacle sensors (no side sensors) and 3-axis accelerometer. I'm planning on using the wall ...
7
votes
2answers
1k views

Instantaneous Center of Rotation for a differential Drive Robot

I want to find the instantaneous center of rotation of a differential drive robot. Assuming I know that the robot will travel with a particular linear and angular velocity $(v,w)$ I can use the ...
6
votes
4answers
270 views

How to find out how far a motor has taken a vehicle?

I have a small motorized vehicle with gears as wheels running up and down a track made of gear racks. How can this robot know when it has run half the track? And what's the best method to keep it from ...
6
votes
3answers
5k views

Why would a drone need a magnetometer? Are an accelerometer and a gyroscope not sufficient?

Why would a drone need a magnetometer? What would the drone do with this information? I think it would be to tell direction, but why would it need this if it has an accelerometer and a gyroscope?
6
votes
1answer
433 views

Stabilizing a Robot Arm at a Specified Height

I have a 4-bar linkage arm (or similar design) for a telerobot used in the VEX Robotics Competition. I want to be able to press buttons on my PS3-style controller to have the arm raise to certain ...
6
votes
3answers
966 views

Visual Odometry options? [closed]

What are the pros/cons of the different visual odometry options? Stereo Camera Optical Flow SLAM other? Criteria: how well it performs vs other odometry options/sensors (lidar, radar) sensor ...
6
votes
1answer
3k views

Technology behind Kiva Systems mobile robots

What kind of sensors and algorithms are the mobile robots of Kiva Systems equipped with?
6
votes
2answers
229 views

Protecting electronics against voltage/current extremes and bad polarity

I have built a robot from a wheelchair that has worked very well thus far. It is now time for me to take the next step. I need to implement a permanent power circuit with proper protection. The ...
6
votes
1answer
159 views

Space elevator: What is still needed, apart from the cable and propulsion?

In order to build and operate a space elevator moving crafts and people into space, there are two big challenges that have not been solved yet: Finding a cable with enough tensile strength, Moving ...
6
votes
3answers
986 views

Motion Model for Holonomic Robot

We are working with an holonomic robot equipped with three (120 degree shifted) omnidirectional wheels. The relative movement is estimated by dead reckoning using wheel encoders. To improve this ...
6
votes
2answers
665 views

ComputerCraft (Minecraft mod) navigation: Collision avoidance and path planning/finding in 2D/3D space

I'm programming Lua for controlling computers and robots in-game in the Minecraft mod ComputerCraft. ComputerCraft has these robots called Turtles, that are able to move around in the grid based(?) ...
6
votes
2answers
2k views

Ackerman steering model

I am trying to create a simulation of a robot with Ackerman steering (the same as a car). For now I'm assuming that it's actually a 3-wheeled robot, with two wheels at the back, and one steering wheel ...
6
votes
2answers
2k views

Choosing path planning and obstacle avoidance algorithm for 2D space

I am working on a 2D space where my robot needs to follow a trajectory while avoiding some obstacles. I've read recently about methods for path planning as "Vector Field Histogram" and the "Dynamic ...
6
votes
1answer
273 views

Using Armatures in Morse Robotic Simulator

I'm trying to add my own robot in Morse 1.1 (using Ubuntu 12.04). I am struggling to add an armature actuator and armature pose sensor to an existing robot. Can someone please explain how this can be ...
6
votes
1answer
158 views

How do I design for a target speed?

I need to make an omni wheeled robot platform (4 wheels), which should go at a minimum speed of 15 cm/s. I have an idea for the design, but since this is my first time doing something like this I ...
6
votes
2answers
353 views

Measuring speed of movement in Webots

I have been experimenting with different fitness functions for my Webots robot simulation (in short: I'm using genetic algorithm to evolve interesting behaviour). The idea I have now is to reward/...
5
votes
6answers
553 views

Effectiveness of a Mobile Robot In Relation To Mass

Do mobile and/or autonomous robots become more or less effective the bigger they get? For example, a bigger robot has bigger batteries, and thus bigger motors, whereas a smaller robot has the exact ...