<?xml version='1.0' encoding='UTF-8'?>
<rss xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0"><channel><title>wwwht</title><link>https://wwwht.github.io</link><description>Daily notes</description><copyright>wwwht</copyright><docs>http://www.rssboard.org/rss-specification</docs><generator>python-feedgen</generator><image><url>https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/202411281106313.svg</url><title>avatar</title><link>https://wwwht.github.io</link></image><lastBuildDate>Thu, 09 Apr 2026 06:42:15 +0000</lastBuildDate><managingEditor>wwwht</managingEditor><ttl>60</ttl><webMaster>wwwht</webMaster><item><title>test</title><link>https://wwwht.github.io/post/test.html</link><description>111所以，**IBVS 虽然是“基于图像”的方法，但并不是完全不需要几何信息**；至少要知道或近似知道深度和内参。</description><guid isPermaLink="true">https://wwwht.github.io/post/test.html</guid><pubDate>Wed, 08 Apr 2026 06:41:49 +0000</pubDate></item><item><title>【论文学习】视觉伺服控制1</title><link>https://wwwht.github.io/post/%E3%80%90-lun-wen-xue-xi-%E3%80%91-shi-jue-si-fu-kong-zhi-1.html</link><description>论文：[https://www.irisa.fr/lagadic/pdf/2006_ieee_ram_chaumette.pdf](https://www.irisa.fr/lagadic/pdf/2006_ieee_ram_chaumette.pdf)

# Intro
视觉伺服： 把计算机视觉得到的信息放进控制回路里，用来控制机器人运动。</description><guid isPermaLink="true">https://wwwht.github.io/post/%E3%80%90-lun-wen-xue-xi-%E3%80%91-shi-jue-si-fu-kong-zhi-1.html</guid><pubDate>Wed, 08 Apr 2026 01:23:12 +0000</pubDate></item><item><title>机器人动力学-2</title><link>https://wwwht.github.io/post/ji-qi-ren-dong-li-xue--2.html</link><description>
![image.png](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/20250901103739105.png?imageSlim)

# 2. Spatial Vector Algebra

空间向量是一种为了**研究刚体动力学**而发明的、更**高效**和**紧凑**的**数学表达“语言”​**。</description><guid isPermaLink="true">https://wwwht.github.io/post/ji-qi-ren-dong-li-xue--2.html</guid><pubDate>Mon, 08 Sep 2025 01:18:05 +0000</pubDate></item><item><title>机器人动力学-1</title><link>https://wwwht.github.io/post/ji-qi-ren-dong-li-xue--1.html</link><description>![image.png|450](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/20250826110011251.png?imageSlim)
好久没有更新了，今天开个新坑，机器人动力学

# 1. Introduction

## 1.1 Dynamics Algorithms

刚体系统的动力学由其运动方程描述，该方程规定了作用在系统上的力与其产生的加速度之间的关系。</description><guid isPermaLink="true">https://wwwht.github.io/post/ji-qi-ren-dong-li-xue--1.html</guid><pubDate>Mon, 01 Sep 2025 02:28:33 +0000</pubDate></item><item><title>逆运动学</title><link>https://wwwht.github.io/post/ni-yun-dong-xue.html</link><description>参考:   
[Inverse Kinematics Techniques in Computer Graphics: A Survey](http://andreasaristidou.com/publications/papers/IK_survey.pdf)
[逆运动学-知乎](https://zhuanlan.zhihu.com/p/450749372)
[逆运动学-知乎2](https://www.zhihu.com/question/400650301/answer/1282203168)  
[https://www.cnblogs.com/21207-iHome/p/9452896.html](https://www.cnblogs.com/21207-iHome/p/9452896.html)
[https://zhuanlan.zhihu.com/p/326387013](https://zhuanlan.zhihu.com/p/326387013)

通过这篇综述学习一下解逆运动学的主要方法.  

综述中主要介绍了 4 个类别的方法, 分别是**解析法 (analytical), 数值法 (numerical), 数据驱动方法 (data-driven) 和混合方法 (hybrid)**. 

# 1. Intro
逆运动学简单来说就是已知末端执行器的位姿, 求解各个关节的变量 $q$ , 在 DH 参数的介绍中, 我们知道了末端执行器的位姿和各个关节变量这件的关系可以抽象成:

$$
r = f(\theta)
$$

其中 $r$ 表示末端执行器的的变量 $r = [r_1, r_2, r_3, ..., r_m]$ 其中 $m$ 表示末端执行器的自由度, 例如只考虑空间中的位置, 那么 $m=3$ ,如果加上转动 $m=6$ .

$\theta$ 表示所有关节变量组成的向量. 逆运动学就是求解 $\theta$ 的过程.

衡量逆运动学方法主要从三个方面: 
1. **运动的平滑度（smoothness of the produced motion）**：IK 求解器应该能够生成平滑的运动轨迹，避免突兀或不自然的动作。</description><guid isPermaLink="true">https://wwwht.github.io/post/ni-yun-dong-xue.html</guid><pubDate>Wed, 22 Jan 2025 07:09:49 +0000</pubDate></item><item><title>DH参数详解</title><link>https://wwwht.github.io/post/DH-can-shu-xiang-jie.html</link><description>![image.png](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/20250114140729096.png?imageSlim)&#13;
参考：[873_ic29-2014.pdf](https://www.yuque.com/attachments/yuque/0/2025/pdf/2636058/1736234338923-b5f416dc-9488-45dd-b362-4c3de6127c4d.pdf)&#13;
# 1. Kinematic Chain&#13;
&#13;
![image.png](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/20250114140658779.png?imageSlim)&#13;
&#13;
&gt; A robotic manipulator may be considered as set of links connected in a chain called **kinematic chain** by joints (figure 1).&#13;
&#13;
维基百科中关于 Kinematic Chain 的概念：&#13;
&#13;
&gt; In [mechanical engineering](https://en.wikipedia.org/wiki/Mechanical_engineering), a kinematic chain is an assembly of [rigid bodies](https://en.wikipedia.org/wiki/Rigid_body) connected by [joints](https://en.wikipedia.org/wiki/Joint_(mechanics)) to provide constrained motion that is the [mathematical model](https://en.wikipedia.org/wiki/Mathematical_model) for a [mechanical system](https://en.wikipedia.org/wiki/Mechanical_system)&#13;
&#13;
简单理解就是由刚体和 joint 组成的一个系统，可以做一些受约束的运动，比如人的手臂是或者机械臂，都可以抽象成一个 Kinematic Chain.&#13;
&#13;
重点理解 joint 和 link 的概念：joint 是关节，常见的有移动副（prismatic joint）和转动副（revolute joint）如图二。</description><guid isPermaLink="true">https://wwwht.github.io/post/DH-can-shu-xiang-jie.html</guid><pubDate>Fri, 17 Jan 2025 05:36:11 +0000</pubDate></item><item><title>CUDA Nsight Compute性能分析</title><link>https://wwwht.github.io/post/CUDA%20Nsight%20Compute-xing-neng-fen-xi.html</link><description>参考：&#13;
https://zhuanlan.zhihu.com/p/707107808&#13;
[BBuf](https://github.com/BBuf/how-to-optim-algorithm-in-cuda/blob/master/cuda-mode/CUDA-MODE%20%E7%AC%AC%E4%B8%80%E8%AF%BE%E8%AF%BE%E5%90%8E%E5%AE%9E%E6%88%98%EF%BC%88%E4%B8%8A%EF%BC%89.md)&#13;
[官方文档](https://docs.nvidia.com/nsight-compute/NsightCompute/index.html#quickstart)&#13;
&#13;
&gt; [!WARNING]&#13;
&gt;在办公电脑上运行，显卡是RTX 1660Ti，对应的nsight compute版本可能已经比较低了。</description><guid isPermaLink="true">https://wwwht.github.io/post/CUDA%20Nsight%20Compute-xing-neng-fen-xi.html</guid><pubDate>Thu, 19 Dec 2024 03:31:53 +0000</pubDate></item><item><title>Roofline模型</title><link>https://wwwht.github.io/post/Roofline-mo-xing.html</link><description>参考：&#13;
Samuel Williams, Roofline Performance Modeling for HPC and Deep Learning Applications, https://crd.lbl.gov/assets/Uploads/S21565-Roofline-1-Intro.pdf  &#13;
YouTube English Presentation：Roofline Hackathon 2020 part 1 and 2 - YouTube  &#13;
Paper：Roofline charts were first introduced by David Patterson and others in 2008 in their ACM paper [“Roofline: An Insightful Visual Performance Model](https://people.eecs.berkeley.edu/~kubitron/cs252/handouts/papers/RooflineVyNoYellow.pdf)&#13;
[YOYO鹿鸣](https://blog.csdn.net/sinat_35360418/article/details/128704146?spm=1001.2014.3001.5502)&#13;
[Telesens](https://www.telesens.co/2018/07/26/understanding-roofline-charts/)&#13;
[Instruction Roofline](https://crd.lbl.gov/assets/Uploads/InstructionRooflineModel-PMBS19-.pdf)&#13;
&#13;
# 引入：什么是较好的性能评价模型&#13;
&#13;
&#13;
&#13;
![image.png](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/202412131334071.png?imageSlim)&#13;
假设在GPU上对内核的循环测试进行性能分析，我们对不同的loop nest得到了随机的flop rates，有的很高，有的很低，这意味着只用GFLOP/s去评价性能可能有失偏颇.&#13;
&#13;
![image.png|425](https://wwwhtblog-1309008871.cos.ap-beijing.myqcloud.com/blog/202412131341297.png?imageSlim)&#13;
假设我们把某CPU代码移植到了Nvida GPU或者是AMD GPU中，将原CPU代码作为baseline（绿色），去对比移植后的代码性能（灰色）提升了多少，然后发现在有的循环中提升了非常多（例如第三根柱子、最后一根柱子），有的循环中只提升了一点点（例如第6根柱子），也不能很好的评价性能。</description><guid isPermaLink="true">https://wwwht.github.io/post/Roofline-mo-xing.html</guid><pubDate>Mon, 16 Dec 2024 01:46:53 +0000</pubDate></item><item><title>【转载】双目视觉模型和三角定位</title><link>https://wwwht.github.io/post/%E3%80%90-zhuan-zai-%E3%80%91-shuang-mu-shi-jue-mo-xing-he-san-jiao-ding-wei.html</link><description>原文：[Yin的笔记本，非常推荐](http://www.yindaheng98.top/%E5%9B%BE%E5%BD%A2%E5%AD%A6/%E5%8F%8C%E7%9B%AE%E7%9B%B8%E6%9C%BA.html#%E4%B8%89%E8%A7%92%E5%AE%9A%E4%BD%8D-triangulation)
图片部分来自[知乎，大黑](https://zhuanlan.zhihu.com/p/460119182)
本文大部分内容来自上方链接，在此基础上加入了一些自己的思考。</description><guid isPermaLink="true">https://wwwht.github.io/post/%E3%80%90-zhuan-zai-%E3%80%91-shuang-mu-shi-jue-mo-xing-he-san-jiao-ding-wei.html</guid><pubDate>Fri, 29 Nov 2024 10:07:09 +0000</pubDate></item><item><title>Markdown语法大全</title><link>https://wwwht.github.io/post/Markdown-yu-fa-da-quan.html</link><description>这是一个markdown格式的测试页面，也是个人经常会使用的格式记录。</description><guid isPermaLink="true">https://wwwht.github.io/post/Markdown-yu-fa-da-quan.html</guid><pubDate>Thu, 28 Nov 2024 02:15:35 +0000</pubDate></item></channel></rss>