Chrissunny94 chrissunny94

Links

http://www.pcl-users.org/PointCloud-Ptr-td3559529.html

https://stackoverflow.com/questions/10644429/create-a-pclpointcloudptr-from-a-pclpointcloud

Test1 - Adding / manipulation Points in const Point Cloud

const pcl::PointCloud<pcl::PointXYZ> cloud(10,10);
const pcl::PointXYZ p(1,1,1);

So, I want to have a GPS Receiver driving a PPS (pulse-per-second) signal to the NTP server for a highly accurate time reference service.

Introduction

There are at least a couple of ways to propagate the PPS signal to the ntpd (NTP daemon) service, plus some variants in each case. However, the GPS device must be seen as a device that sources two different types of data:

the absolute date and time, and
the 1Hz clock signal (PPS).

The first one provides the complete information (incl. date and time) about when now is, but with poor accuracy because data is sent over the serial port and then encoded using a specific protocol such as NMEA (National Marine Electronics Association). PPS provides instead a very accurate clock but without any reference to absolute time.

ouster-lidar/ouster-sdk#245 , good description about how to deskew the pointcloud data .

	# Use NVIDIA CUDA 11.8 base image with Ubuntu 22.04
	FROM nvidia/cuda:11.8.0-devel-ubuntu22.04

	# Set noninteractive mode for apt
	ENV DEBIAN_FRONTEND=noninteractive

	# Install basic utilities and dependencies
	RUN apt update && apt install -y \
	curl gnupg2 lsb-release \
	git cmake build-essential \

	def euler_from_quaternion(quaternion):
	"""
	Converts quaternion (w in last place) to euler roll, pitch, yaw
	quaternion = [x, y, z, w]
	Bellow should be replaced when porting for ROS 2 Python tf_conversions is done.
	"""
	x = quaternion.x
	y = quaternion.y
	z = quaternion.z
	w = quaternion.w

	/*
	This is an example of how to use the PCL filtering functions in a real robot situation.

	This node will take an input depth cloud, and
	- run it through a voxel filter to cut the number of points down (in my case, from ~130,000 down to 20,000)
	- with a threshold to remove noise (requires minimum 5 input points per voxel)
	- then transform it into the robot footprint frame, i.e. aligned with the floor
	- subtract the robot footprint (our depth sensor's FOV includes the robot footprint, which changes dynamically with the load)
	- subtract points in the ground plane, with different tolerances for near or far
	- ground plane by default z = 0, but

	# will need to be tweaked for your project
	make_minimum_required(VERSION 3.5)
	project(test_ros_pb11)

	# Default to C99
	if(NOT CMAKE_C_STANDARD)
	set(CMAKE_C_STANDARD 99)
	endif()

	# Default to C++14

	```
	Input Format

	A list of elements. An element of list to be counted.

	Sample Input 0

	[1,2,2,3,4,5,5,4,3,3,4,3,3,5]
	```