hector

使用hector-slam和Kinect V1建图

扶醉桌前 提交于 2020-04-27 20:20:05
一.建图实际操作 下载源码测试源码,depthimage_to_laserscan,参考 https://blog.csdn.net/u010925447/article/details/56494680 解压到你的ros工作空间路径中。 使用catkin_make编译功能包。 分析launch文件,修改使其在自己的平台上可用:参考 https://www.jianshu.com/p/429e59d48322 运行launch文件 启动转换节点:roslaunch depthimage_to_laserscan sample_node.launch(包含主节点和深度相机启动节点) 二.利用深度相机仿激光数据创建地图 下载hector_slam_example:下载地址 https://github.com/chenxingzhe/hector_slam_example,编译(cmake)(无需里程计即可建图,核心节点hector_mapping订阅/scan话题) sudo apt-get install ros-indigo-hector-slam Install the dependency packages:rosdep install hector_slam_example 在启动之前如果你用的是kinect,那就修改一下launch文件 然后就是roslaunch

ros开发之pointcloud_to_laserscan功能包浅析

你离开我真会死。 提交于 2020-04-24 12:33:11
ROS智能移动小车开发过程中需要slam建图定位,我这边具备的硬件条件为:Robosense 16线激光雷达,笔记本电脑(ubuntu16.04,Ros-Kinetic),当前不借助里程计完成SLAM建图定位的只有二维建图的hector-slam算法,需要将激光雷达三维点云转换为二维点云数据,功能包的配置实现过程可以参考: https://blog.csdn.net/geerniya/article/details/84880514 接下来主要记录pointcloud_to_laserscan功能包三维点云转二维原理: 原理实现主要在pointcloud_to_laserscan/src/pointcloud_to_laserscan_nodelet.cpp中的void PointCloudToLaserScanNodelet::cloudCb(const sensor_msgs::PointCloud2ConstPtr& cloud_msg)中: 输出数据类型为sensor_msgs/LaserScan,终端输入rosmsg show sensor_msgs/LaserScan得到具体格式如下: std_msgs/Header header uint32 seq time stamp string frame_id float32 angle_min float32 angle

Retrieve multiple columns value from Cassandra using Hector client

对着背影说爱祢 提交于 2020-01-25 08:57:25
问题 I am working with Cassandra and I am using Hector client to read and upsert the data in Cassandra database. I am trying to retrieve the data from Cassandra database using hector client and I am able to do that if I am trying to retrieve only one column. Now I am trying to retrieve the data for rowKey as 1011 but with columnNames as collection of string. Below is my API that will retrieve the data from Cassandra database using Hector client- public Map<String, String> getAttributes(String

pagination in cassandra based web application

时光怂恿深爱的人放手 提交于 2020-01-15 23:03:08
问题 How can i do a pagination in cassandra based web application. I am using spring MVC on server side and jquery on client side. I tried this but was not sutisfied. My row key is UUIDType and every time i am sending the start key as string from client browser so dont know how to convert it back to UUID. A simple example will be appriciated. 回答1: Spring-data has this functionality pre-rolled : http://static.springsource.org/spring-data/data-jpa/docs/current/reference/html/repositories.html#web

pagination in cassandra based web application

岁酱吖の 提交于 2020-01-15 22:59:39
问题 How can i do a pagination in cassandra based web application. I am using spring MVC on server side and jquery on client side. I tried this but was not sutisfied. My row key is UUIDType and every time i am sending the start key as string from client browser so dont know how to convert it back to UUID. A simple example will be appriciated. 回答1: Spring-data has this functionality pre-rolled : http://static.springsource.org/spring-data/data-jpa/docs/current/reference/html/repositories.html#web

How to use cql queries to get different datatypes out of cassandra with java client hector

时光毁灭记忆、已成空白 提交于 2020-01-12 07:11:27
问题 I'm new to cassandra and hector so i'm trying to execute cql queries but the problem is that not all columns are of type string so how dow I execute the query "select * from users"? My column family looks like this: UPDATE COLUMN FAMILY users WITH comparator = UTF8Type AND key_validation_class=UTF8Type AND column_metadata = [ {column_name: full_name, validation_class: UTF8Type} {column_name: email, validation_class: UTF8Type} {column_name: state, validation_class: UTF8Type, index_type: KEYS}

Composite Type Wildcard on last component

北城余情 提交于 2020-01-07 05:08:09
问题 I have the following code segment. The composite column has two compoents. Is it possible to retrieve columns if I know only the first component? In some sense, apply some dilcards election on the some of the components of the composite (especially the last component). Thanks. Mutator<String> mutator = HFactory.createMutator(keyspace, stringSerializer); String key="TX:512"; String CF="StateNpaIndexStatic"; HColumnImpl<Composite, String> column = new HColumnImpl<Composite, String>(cs,

Cassandra Schema Design

我们两清 提交于 2019-12-24 16:48:42
问题 I'm continuing exploring Cassandra and I would like to create Student <=> Course relation which is similar to Many-to-Many on RDBMS. In term of Queries I will use the following query; Retrieve all courses in which student enrolled. Retrieve all students enrolled in specific course. Let's say that I create to Column Families. one for Course and another for Student. CREATE COLUMN FAMILY student with comparator = UTF8Type AND key_validation_class=UTF8Type and column_metadata=[ {column_name

Cassandra Schema Design

ぃ、小莉子 提交于 2019-12-24 16:48:04
问题 I'm continuing exploring Cassandra and I would like to create Student <=> Course relation which is similar to Many-to-Many on RDBMS. In term of Queries I will use the following query; Retrieve all courses in which student enrolled. Retrieve all students enrolled in specific course. Let's say that I create to Column Families. one for Course and another for Student. CREATE COLUMN FAMILY student with comparator = UTF8Type AND key_validation_class=UTF8Type and column_metadata=[ {column_name

Hector (Cassandra) Delete Anomaly

筅森魡賤 提交于 2019-12-22 05:42:30
问题 Using hector (cassandra client) when I try to do delete, it deletes the columns…but leaves the row key behind…does anyone know why, and how can I delete that row key as well ? 回答1: This is expected when using Cassandra. Since it deletes by writing tombstones the data is still there until the next compaction. Eventually it will go a way completely, but your application code must be aware that an empty row is the same as a deleted row. 回答2: Actually, it will go away in the next compaction that