Questions tagged [design]
Mechanical, electronic or programmatic design of a robot.
148
questions
92
votes
4
answers
19k
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 ...
22
votes
4
answers
4k
views
Why are quadcopters more common in robotics than other configurations?
I've noticed that almost all research being done with helicopter robots is done using quadcopters (four propellers). Why is there so little work done using tricopters in comparison? Or a different ...
22
votes
5
answers
2k
views
Is it better to have batteries distributed at the rotors or the center of the multicopter?
I've seen 3 approaches to mounting batteries on a multicopter:
All the batteries rigidly mounted near the center of the airframe
All the batteries in a bag hanging under the center of the airframe
...
19
votes
3
answers
3k
views
What is the best way to power a large number (27) servos at 5 V?
I apologize if this question may sound a little vague. I am working on a robotics project that will contain 27 servos of various sizes and I am having trouble figuring out how they should be powered.
...
18
votes
2
answers
23k
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 ...
18
votes
3
answers
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 ...
18
votes
3
answers
13k
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 ...
14
votes
3
answers
1k
views
How can I control a fast (200Hz) realtime system with a slow (30Hz) system?
We are currently designing a mobile robot + mounted arm with multiple controlled degrees of freedom and sensors.
I am considering an architecture in two parts:
A set of realtime controllers (either ...
14
votes
2
answers
5k
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 ...
13
votes
2
answers
2k
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
votes
2
answers
2k
views
Choosing the right dimensions for an underwater glider
I'm looking to potentially build an underwater glider, a type of submarine that's slow but can operate on extremely low power draw. However, in order for it to work effectively I've found several ...
12
votes
3
answers
11k
views
When should FPGAs be used in Robotics?
FPGA has good points such as a lot of IO points but then again you need to think things on very low level with flip-flops and pioneer on areas where things are not yet mature -- for example see this ...
10
votes
2
answers
978
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 ...
10
votes
4
answers
4k
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
votes
1
answer
4k
views
Building Robotic arm joint
I am very new to robotic design and I need to determine what parts I will need to assemble an arm joint. The joint will contain one timing belt pulley which a remote motor will be turning, a forearm ...
8
votes
3
answers
9k
views
How do I motorize the elbow socket and other joints in a powered exo-skeleton?
How would you motorize the joints in an Iron Man suit? You need something fairly shallow, I would think, probably dual servos sitting on either side of an elbow or knee joint or either side of your ...
8
votes
2
answers
1k
views
Getting started with robotic arm design
I would like to design a robotic arm to hold a weight X at length Y (in my case I want to hold X=2.5 lbs at Y = 4 inches). Starting out simply, I would like try building an arm with a gripper plus one ...
7
votes
2
answers
5k
views
How to know the desired orientation of a quadcopter?
I am trying to simulate a quadcopter model on Simulink. I want to implement a PID controller for each of X,Y,Z and phi,theta, psi angles. PID gets the error, as input, which is to be minimized.
For ...
7
votes
2
answers
5k
views
Robotic part to dispense candy
I'm a complete newbie trying to build a simple robot that dispenses candy (M&M, skittles, etc). However, since I'm not familiar with the field, I'm having a hard time googling because I don't ...
7
votes
3
answers
2k
views
How to open a sliding window?
I live in an apartment that has sliding windows in it. The apartment is naturally warm because we live above a mechanical room, such that we either opened the windows or ran the air conditioning ...
7
votes
1
answer
2k
views
MEMS accelerometer calibration
I am trying to calibrate a MEMS accelerometer. I was able to calibrate it for the current axis which is parallel to gravity and shows correctly, 1g. But the other two axes which should be 0.00g are ...
7
votes
2
answers
319
views
Is there a tool for building and analysing robots (kinematics, control) visually?
I am reading research papers about robotics and many of them follow the same pattern:
some construction is established
kinematical formulas are read from the mechanical structure
the state space is ...
6
votes
2
answers
350
views
Drone targeting
Imagine a "drone" and a target point on a 2d plane. Assuming the target is stationary, there are eight parameters:
...
6
votes
1
answer
708
views
What do quadcopter propeller specifications mean?
I'm trying to figure out the diameter of tri-blade propellers.
I found a 7x3x4.5 blade, I'm trying to understand the measurements. Is the '7' the length of the blade giving the prop a 10.5" diameter? ...
5
votes
6
answers
625
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 ...
5
votes
2
answers
587
views
If you can create pure yaw motion with a quadcoptor then why won't this work with a tricoptor?
An answer to the question Why are quadcopters more common in robotics than other configurations? said:
You need 4 degrees of freedom to control yaw, pitch, roll and thrust.
Four props is therefore ...
5
votes
1
answer
498
views
Gears modeling in Google SketchUp and SketchyPhisics
I'm trying to make differential in Google SketchUp using this tutorial http://support.ponoko.com/entries/21249896-Gears-and-Joints-with-SketchUp-Sketchy-Physics for gears modeling.
But I have problem: ...
5
votes
1
answer
348
views
Dynamic braille interface
I'm a newbie in robotics, and I'm doing a project on dynamic Braille interface. Basically it's a 8*8 array of pins, which can be either totally up or down. How to use least motor as possible?
I'm ...
4
votes
2
answers
84
views
Is it better to use software or hardware for object sorting?
For a sorting machine where the objects to be sorted have various sizes, color, shapes, and patterns, is it more optimal (in terms of minimal time of the overall process and maximal precision and ...
4
votes
1
answer
85
views
How important are events like "Robocup" to the advancement of Robotics in general?
Are events like Robocup advantageous to the development of robotic advancement?
Or is it merely entertainment which advances robotics by allowing entry level participation which helps maintain ...
4
votes
1
answer
1k
views
How to get manufactured part from CAD file?
I am working through the book Learning Robotics using Python, which is for Python programmers who want to learn some robotics. Chapter 2 shows you how to use LibreCAD to design the plates and poles ...
4
votes
1
answer
1k
views
Submarine screw and the isolation from the water [duplicate]
How does the submarine prevent water flow through the screw mechanism? The mechanism rotates the screw so there should be a little gap, how come the water doesn't come through this gap in to the ...
4
votes
1
answer
311
views
How to perform decoupling between decision making and action execution in ROS2?
Hi I'm making a robot using:
ros2 foxy
OS Ubuntu Linux 20.04.2 LTS (Focal Fossa).
Linux 5.8.0-59-generic
I built an Action based on the tutorial Building an Action Server and Client. Then expanded ...
4
votes
2
answers
455
views
What should be the ideal ratio for link lengths ( L1/ L2) of a 2 link manipuator robot with revolute joints?
I am working on making a CAD model of a two link robotic manipulator, with link lengths around 15-20 cm. I am unable to figure how to set their mutual ratio and I want to know whether there is some ...
4
votes
2
answers
150
views
Air hockey with a robot as an opponent
I'm not sure if this is the right place to post this but here goes.
So, as the title states, I'm planning on building a desk that doubles as an air hockey table which has a robot on the other side.
...
4
votes
1
answer
6k
views
How to find a solution for quadcopter PID control
I've built a quadcopter and a rig to safely test it on. I'm working on the PID for controlling the roll pitch and yaw. I understand how a PID works on a more simple plant like say a robot with wheels ...
4
votes
2
answers
89
views
How do I dispense a greasy fluid?
I'm a agricultural engineering student and complete newbie trying to build a simple mechanism attached to a drone that dispenses a grease-type fluid. However, since I'm not familiar with the field, I'...
4
votes
1
answer
409
views
MCU architecture design
Are there any standards regarding single vs multiple MCU in a robotic system? More specifically, if a single MCU can handle all of the sensor data and actuator controls, is it better to use a single ...
3
votes
5
answers
2k
views
Why Make Bipedal Robots?
A friend and colleague of mine who studies robotics says that bipedal robots present much greater challenges for stability and locomotion than those with more legs.
So why is there so much effort to ...
3
votes
1
answer
689
views
Can a state matrix have a row of zeros?
While formulating a state matrix of a system, say a system of a typical cruise controller,
\begin{equation}
\begin{bmatrix}
\dot{v}
\end{bmatrix} = \begin{bmatrix} -\frac{b}{m} \end{bmatrix} \begin{...
3
votes
5
answers
600
views
Quadcopter frame design
Quadcopter frames seem to consistently follow the same X design. For example:
I'm curious to know why that is. It certainly seems like the most efficient way to use space but is it the only frame ...
3
votes
3
answers
2k
views
How many amps do I want my Switching BEC to provide?
I'm trying to power 7-12 servos, and I was under the impression that each one would need about an amp, but in looking around for an appropriate BEC to supply them, I notice that most seem to output ...
3
votes
1
answer
1k
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
1
answer
745
views
Counterweight in arm designs
I wonder why most robotic arms use large J2 (shoulder) motors rather than counterweights. What sort of complexity do they add to the design beside increase in overall weight? In fact, rather than ...
3
votes
1
answer
3k
views
Alternative way to perform Pole zero cancellation?
I've read a lot places that making a controller which cancels the unwanted pole or zero is not good designing practice for designing a controller..
It should make the system uncontrollable which off ...
3
votes
3
answers
772
views
Atlas Robot Reference
Boston Dynamics keeps making great robots, however, I dont see any papers that they publish. Although now I can find papers on people using the ATLAS robot, I can not find an original paper detailing ...
3
votes
1
answer
268
views
Is finished plywood a comparable prototyping substitute for polyoxymethylene?
I'm working on a robot with a team, and we're building our robot out of acetal polyoxymethylene (POM) (specifically, delrin) plastic. However, we'd like to prototype the robot before we build it out ...
3
votes
2
answers
2k
views
Design Calculations & Mathematical Modeling of Tricopters
I have been studying about building a tricopter. But I couldn't find the design calculations or mathematical modeling of the tricopter any where over the internet.
What are the mathematical ...
3
votes
1
answer
230
views
Comparison of Balance Bot design
I'm planning to build a Balance Bot and I would like to know which design should I go with. There's a vertical design such as the ArduRoller and on the other hand, there's the typical stacked type of ...
3
votes
1
answer
749
views
Linear slider motor mount location - Pros/cons
I'm currently designing a linear camera slider, that will be used to hold camera equipment weighing just about 15 Kgs including all of the lenses and monitors and everything else.
For those who don't ...