I have looked up a lot of papers to figure this out but I need some help guys.
I am currently working on transforming coordinate frame from Base_link to laser_link. In tuturials, we assume that the relationship between laser and base is known.
However, I would like to know if is there anyway to calibrate this relationship assuming that the relationship contains error or is unknown. Thank you guys!
Related
I have a cost network, but it's not a street mapping network. I know the nodes and edges as I defined them. pgRouting looks like a good choice, but every single example I can find uses Open Street Map as the data. I don't have GPS coordinates. The x1,y1 for nodes makes no sense in my graphs, my nodes have specific ids, not coordinates. The costs aren't calculated from the coordinates, they're assigned by me on the various edges based on domain knowledge specific to my domain.
Are there any examples of how to create a custom network in pgRouting? I'm really struggling because the examples are "and then you use this tool to import OSM data"...which doesn't help me at all.
#Chris Kessel
I don't know if this is still relevant, but it may help others:
Basically, what you need to have is a table with edges, where in column 'source' is the id of a node on one end of the edge and in column 'target' - id of the node on the other end. You also have to have a defined cost for the edge, I'm not sure what this will be for you - usually it's distance or time units.
Ususally this is done with geo info using pgr_createTopology function, but in your case you will need to just create this yourself, I suppose.
I think this link can help you:
https://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/
The answer to the question "Are there any examples of how to create a custom network in pgRouting?" is Yes there are.
thanks in advance.
I am new to the multiple object tracking field. So, I have been working on this for a couple of days. I have developed my first version of a single object tracker using an extended Kalman filter. I am estimating position, velocity by assuming a constant acceleration model. Now my question is how can I convert the existing model for multiple objects tracking. The main problem is I am using radar data. So, I am not able to get the references for developing the tracker. So, One good example or steps to achieve can help me in understanding the concept.
The answer to this question depends on a lot of things. For example, how much control and knowledge do you have over the whole system? If you know how many targets you need to track you can add all of them to the Kalman Filter state and for every measurement you perform data association to find out to which object a given measurement belongs. An easy association metric would be nearest neighbor.
If you don't know how many targets there will be you will want to implement a track management where each target you are tracking represents a track and you can model birth and death probabilities of targets.
Multi Target Tracking is a vast field and if you want to have an in-depth mathematical introduction I would recommend the 2015 survey paper "Multitarget Tracking" by Ba-Ngu Vo et al. You should be able to find a preprint pdf online.
If you are looking more for a lightweight tutorial I would assume it should be possible to find some tutorial or example code online where to start. As mentioned in the first paragraph, nearest neighbor association for a fixed amount of objects might be a good first step.
Well I am working on a very interesting project concerning a gear system that will rotate a shaft and some gear systems. I am following a tutorial from matlab
User-Added Coordinate Systems
on how to decouple and have two gears rotating.
Well, I need some hold on understanding the following figure, that is the output of the above link.
So what I do next is un-weld the two gears by deleting the conection of F1, and later introducing the common gear constraint by conecting it to the SMLINK port on both gear"_" boxes. I get and unusual message that says:
" * Model not assembled: position violation * Resolve this issue in order to simulate the model."
Can some one explain what is happening?
Also, what is the difference between 1st generation, and multibody Simscape? can I have joint actuators in both cases? and if so how would i be able to implement such in the example given above?
for those who would like to answer, but dont have solid works, the gear block boxes, and figure is the following:
It looks like the right thing to do, but how have you parameterised your gear constraint? Have a look at mech_user_added_css.mdl for the correct way to do it (it's one of the SimMechanics example, but it uses the first generation engine and blocks). Make sure the gear circle radii match what's in the first generation example. It will also help to answer you question about first generation vs. second generation.
SimMechanics was one of the early physical modelling tools produced by MathWorks. A few years later, they produced Simscape and the Simscape engine for modelling multi-domain systems. This was much more powerful than the original SimMechanics, so over the years they migrated SimMechanics functionality over to Simscape, but have kept the original first generation blocks for compatibility issues. Have a look at some of the first generation vs second generation examples and blocks to get an idea.
I am implementing an app which measures the how much distance it has moved .For example if my device felldown from my table to ground ,then I would like to calculate the distance.So Kindly help me to do this. Let me know if my question is not clear.
Thanks in advance.
Your question is very clear : you want to compute the second level integral of the acceleration, which theorically is possible, by supposing the speed null at some time, but I really doubt you could get something precise enough to make any sense (as in many integral computations).
This isn't done today because the error is too big. Done in hardware (for permanent integration of the acceleration) it could be a little more precise but probably not enough to really compute a distance in any acceptable sense of the word "accuracy".
If you want to try it by yourself, here's a document describing more in detail the approach : http://perso-etis.ensea.fr/~pierandr/cours/M1_SIC/AN3397.pdf
I am working with Zillow neighborhood data provided freely at http://www.zillow.com/howto/api/neighborhood-boundaries.htm . I have successfully Imported the data with SRID 4120. Now I am trying to find out the neighborhoods by giving a coordinate(lat,long) and a radius. Finding a neighborhood in which my point exists is easy and is done through STIntersect method. I am actually confused with STDistance. For complete WA state data, It is giving me a maximum distaince of 4.xxx relative to any point in the wa. My question is what is the good way to find the points which are in a given radius and what is the unit.
thanx
zAfar
Got it, I was importing geography data into geometry column.