Questions tagged [wheeled-robot]

Wheeled-robot is a subtype of mobile robots which uses motor driven wheel(s) to be able to move.

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19
votes
6answers
5k views

Robot never goes straight

I am using 2 identical DC motors and a castor wheel. The motors are connected to L293D motor driver and are controlled by RPi. The robot is not going straight. It veers off to the right. I am ...
16
votes
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 ...
13
votes
2answers
921 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 ...
10
votes
3answers
22k views

What are the signs that a servo might be broken?

I just got a kit and im not sure if its me or not but it appears one of the continuous servos might be broken. What happened first when I plugged it into the microcontroller, it made a humming sound ...
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
1answer
4k views

How does rocker bogie keep the body almost flat?

How does rocker-bogie mechanism keep the body flat / keep the solar panel almost flat all the time? I know there is an differential system that connect both rocker bogie (left and right) together. But ...
7
votes
4answers
930 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
2answers
3k views

Cascading PID DC Motor Position & Velocity Controllers

I'm trying to build a robot with a differential drive powered by two DC Motors. First I implemented a PID Controller to control the velocity of each motor independently. Estimated the TF using the ...
7
votes
4answers
3k views

Robot docking for self-recharging

I want to build a simple obstacle avoider robot, but this time I want it to be self-recharging so I am building a dock for this purpose, so I want it to be able to locate the dock and go for it when ...
6
votes
2answers
312 views

Holonomics Movement vs Holonomics Constraint

I'm reading Mechanics of Robotic Manipulation by Matthew T Mason and I stumbled upon the concept of kinematic constraints. The book mentioned about two types of constraints: holonomic and nonholonomic ...
6
votes
2answers
2k views

L293D won't turn motor backwards

My small robot has two motors controlled by an L293D and that is controlled via a Raspberry Pi. They will both go forwards but only one will go backwards. I've tried different motors and tried ...
6
votes
2answers
234 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 ...
5
votes
3answers
198 views

F/OSS Optical Object Avoidance

I am beginning work on a larger scale, 250-350 lbs wheeled robot and looking to use both optical and other means of object avoidance. I am concerned with a robot this large causing issues with running ...
5
votes
1answer
6k views

How to program a three wheel Omni?

I have created a three wheeled omni robot like the diagram below. Now I am unsure of how to program it. I want to use a single joystick so one x and one y value. The values for x and y are between -1 ...
5
votes
1answer
4k views

12V compressor and air pressure control

I am trying to make a simple robot with few functionality for someone, one of these functionality is inflating a balloon inside the robot, I know how to control a compressor using Arduino but the ...
5
votes
2answers
336 views

Cheapest 3D printer for gears?

It would be incredibly useful if I could print my own gearing solutions, even if I have to print the gears one at a time. However, I do not know how the market's cheapest printers will accommodate ...
5
votes
1answer
847 views

Strafing of Mecanum wheels

I am part of my college robotics team. We are participating in Robocon 2014 and are thinking about using mecanum wheels. We have done our research but one thing id like to clarify is: Does the number ...
5
votes
2answers
394 views

following a trajectory with LQR controller

We want our wheeled robot to follow a (rather short) trajectory. We wrote an LQR controller, which works well in simulation. However, our robot offers two problems: 1.) The reported state information ...
5
votes
1answer
151 views

Robot positioning problem

The problem i am facing is to try and calculate the x and y position of a robot with dead reckoning. Reading from the encoders and getting proper rotations of the wheels of my robot works. The robot ...
5
votes
1answer
391 views

Tuning Line follower PID constants with Q-learning

I am currently working on a line follower buggy and have managed to tune the PID constants​ manually. The buggy follows the line at a moderate speed. I will now like to take things further and learn ...
4
votes
3answers
1k views

Plotting location using wheel encoder data

Context: I am working with the SFU Mountain Dataset [http://autonomylab.org/sfu-mountain-dataset/] The UGV image - via the SFU Mountain Dataset website: I have used the following state update ...
4
votes
1answer
177 views

Sensors' field of view in car driving

I want to develop an autonomous driving RC car. For detecting obstacles, I plan to mount 3-5 ultrasonic sensors in the front and in the back the car. What is the minimum necessary combined field of ...
4
votes
1answer
138 views

TWIP robot - DC gearmotor speed/Encoders

I'm working on a self-balancing TWIP (Two-Wheel Inverted-Pendulum) robot project which will be using two brushed DC gearmotors with encoders. As there were no speed constraints for the robot (and ...
4
votes
2answers
365 views

Choosing motor and battery for a robot

I have a project which requires a robot to move around a room with a flat surface (concrete floor). The robot must carry a laptop. I estimated that the total weight would be 6-7kg (including motors, ...
4
votes
1answer
182 views

Rotation ratio between left rocker and right rocker in rocker-bogie system

Following, the previous question, I am trying to calculate how much one rocker would rotate when the other is being rotated. I attached my calculation here. I am trying calculate the rotation of gear ...
4
votes
1answer
289 views

Handling PID DC motor control at low speeds

I am building a 4 wheel rover and am using PID DC motor control for the back set of wheels. The feedback for the speed is provided by Hall effect sensors, with two pulses per rotation. This means ...
4
votes
1answer
222 views

Quadrature Encoder Counts

Actually , I have been since two weeks looking for convinced and final solution for my problem , actually I am completely lost , I am working on mobile robot (Rover 5) with 2 motors , 2 encoders . the ...
4
votes
1answer
68 views

Making a robot go in a straight rate - sampling rate for motor PID

I'm trying to build a robot/rover based on Raspberry Pi 3 At the moment I'm straggling with a basic driving in a straight line. I'm in a process of tuning my PID code andI'm not sure what sampling ...
3
votes
2answers
505 views

Multi-Rate Sensor Fusion using EKF

Context: I have an IMU(a/g/m) + Wheel Odometry measurement data that I'm trying to fuse in order to localize a 2D (ackermann drive) robot. The state vector ...
3
votes
1answer
196 views

Choosing the state vector for an EKF

Could someone help me understand the logic behind choosing a particular state space vector for an EKF? Context: Say there is a 4 wheeled robot that operates only in 2D. It is equipped with an ...
3
votes
2answers
829 views

Is there a name for the steering style/wheel actuation used on Curiosity?

I read up on the wheels of Curiosity, and also about the suspension. But is there a name for the steering? It looks similar in nature to the front landing gear on an airplane, but searching those ...
3
votes
3answers
1k views

2D path following robot, converting XY axis path to input on wheels

at the moment I am creating an android program, that will steer my simple, 3 wheel (2 motors, 1 for balance) robot to move online following the path drawn by user on his screen. The robot is operated ...
3
votes
1answer
242 views

Does a vehicle with defferential gear still move straight?

I am in the concept phase of a driving robot. The two wheels on the front axle will be powered, while the rear will be dragged along. The rear is also responsible for steering but this has noting to ...
3
votes
2answers
449 views

Difference between g-value and rhs-value in Lifelong Planning A*

What is the difference between g-value and rhs-value of Lifelong Planning A* algorithm? According to this link, D* Lite, g(s) directly correspond to the g-values of an A* search, i.e. g(s) = g(s') + ...
3
votes
1answer
429 views

Accurate Wheeled Robot Odometry

I'm looking for a "good" algorithm/model for wheeled odometry estimation. We have encoders on the two back wheels of the tricycle robot, and IMU on the controller board. Currently we use MEMS gyro for ...
3
votes
1answer
827 views

Which is easier/cheaper: Hbridge vs ESC for controlling a motor?

I was able to find a small ESC for about $12 off of ebay. If you were designing a robot, would you see that and think? \$12 bucks for an ESC that connects to simple pulse-wave interface - sign ...
3
votes
1answer
34 views

What parameters can be/should be looked on while deciding to work with a microcontroller in a bot

I understand that choosing a microcontroller is all based on the needs and that there is no perfect Mcu.presently I have to select an MCU for a robot my team is building for the 2018 Abu robotics ...
3
votes
2answers
980 views

How to move a robot to a point while avoiding obstacles?

I am trying to move a robot in a straight line from point A, to point B. The robot's primary sensor is a Hokuyo URG-04LX-UG01 LIDAR that gives me the magnitude and direction of each point it detects ...
3
votes
2answers
422 views

Two-wheeled self-balancing robot - Choosing the control system

Would an Arduino Uno have the precision-timing required (using only firmware) to control a two-wheeled inverted pendulum robot, or would it need a RTOS? Note: Thanks for both answers, they both ...
3
votes
1answer
108 views

Fit robot simulator to robot

I have odometry data $(x, y, angle)$ of a real two-wheeled robot, who received control commands $(forward speed, angular speed)$. Now I want to code a motion model (in C++ (/ROS)) which should follow ...
3
votes
1answer
681 views

Rocker bogie suspension stability

From the designs usually shown of rocker bogie systems, the whole weight of platform seems to be supported by only one rod, be it differential bar or gear. Isn't this a bit unstable system because if ...
2
votes
2answers
3k views

Kinematics of a 4 wheeled differential drive robots

I have a 4 wheeled differential drive robot, like the Pioneer 3-AT. There are only two motors, one for left wheels and one for right wheels. I want to send velocity commands to the robot, I'm using ...
2
votes
1answer
115 views

How has the Mars Exploration Rover (MER) has been working for 11 years if it was designed for 90 Sol? [closed]

The Mars Exploration Rover (MER) Opportunity landed on Mars on January 25, 2004. The rover was originally designed for a 90 Sol mission (a Sol, one Martian day, is slightly longer than an Earth day at ...
2
votes
3answers
2k views

Particle filter weight function

I am trying to implement a particle filter in MATLAB to filter a robot's movement in 2D but I'm stuck at the weight function. My robot is detected by a camera via two points, so a single measure is a ...
2
votes
2answers
240 views

Motion planning and robot controlling

I am stuck with understanding how can I make my robot move along planned path. For instance, if we have a grid map of an environment and applied, for example, A* to plan a path then after that we have ...
2
votes
2answers
1k views

Self balancing robot control system strategies [closed]

I’m in the early stages of designing a self-balancing robot as a way to refresh my knowledge on control theory, which has been gradually slipping away since graduating about a year and a half ago. I'm ...
2
votes
3answers
3k views

How to find kinematics of differential drive caster robot?

I'm working on a little project where I have to do some simulations on a small robot. I my case I'm using a differential-drive robot as one of the wheels of a bigger robot platform (which has two ...
2
votes
2answers
84 views

Detect road surface in a traffic scene point cloud

I want to analyze a traffic scene. My source data is a point cloud like this one (see images at the bottom of that post). I want to be able to detect objects that are on the road (cars, cyclists etc.)....
2
votes
1answer
187 views

Reverse lift mechanism

I have made a RC robot from a wheelchair and I'm planning to attach a snow plow. I'm wondering if there is any mechanism that would be able to lift the plow when reversing. I have only 2 channel ...
2
votes
3answers
113 views

Interference caused by multiple robots during task completion

Suppose there is an area to survey. If we deploy one robot it takes time T to sweep the area. Now if we deploy 2 robots, we would expect it to take time T/2. However in reality, because we are sending ...