Jackmin's blog

双系统时间冲突问题解决方案

Tue, 24 Mar 2026 00:00:00 GMT

安装了双系统的电脑上先打开ubuntu，再重启打开windows会造成windows的时间错误？

核心原因

Linux (Ubuntu) 和 Windows 对硬件时钟（Hardware Clock / BIOS Time）的默认理解不同。电脑主板上有一个独立的硬件时钟（RTC），即使断电也能走时。操作系统启动时会读取这个时间，然后根据自己的设置（时区）显示给用户。

Windows 的逻辑：
- 认为硬件时钟存储的是 本地时间 (Local Time)。
- 例如：如果你在北京（UTC+8），当前时间是 20:00，Windows 会把硬件时钟设置为 20:00。
Linux (Ubuntu) 的逻辑：
- 认为硬件时钟存储的是 协调世界时 (UTC)。
- 例如：如果你在北京（UTC+8），当前时间是 20:00，Linux 会把硬件时钟设置为 12:00 (20:00 - 8小时)。
- 启动时，Linux 读取硬件时钟的 12:00，加上 8 小时时区偏移，显示为 20:00。

解决方案

修改 Ubuntu 设置（推荐）

让 Ubuntu 像 Windows 一样，把硬件时钟当作“本地时间”来处理。进入 Ubuntu 系统。打开终端（Terminal）。输入以下命令并回车（需要输入密码）：

timedatectl set-local-rtc 1 --adjust-system-clock

验证是否设置成功，输入：

timedatectl

查看输出中是否有 RTC in local TZ: yes。如果有，说明设置成功。重启进入 Windows，此时时间应该已经正确了。如果还不对，在 Windows 里同步一次时间，以后就不会再变了。

AI模型真伪判别

Tue, 24 Mar 2026 00:00:00 GMT

提问

我想洗车，洗车店距离我家 50 米，你建议我开车去还是走路去？正常来说现在的顶尖大模型回答肯定是开车，如果ai回答别的，大概率是假的，当然也有可能是没开深度思考

内置知识库截止时间

大部分新模型的内置训练知识库都是比较新的，而且网上可以很简单的查到，如果你的ai回答时间比较早那很可能掺假

伺服系统与电机选型

Mon, 23 Mar 2026 00:00:00 GMT

舵机分析视频和具身智能案列视频

伺服系统 Servo system

三种电机选型对比：

工程选择：

具体型号的选择，注意减速比和电压

PID和MPC

Mon, 23 Mar 2026 00:00:00 GMT

PID

数学原理剖析 📐 假设我们要控制一个系统的输出值$$y(t)$$（比如无人机的高度），使其达到目标值 $r(t)$。那么误差就是 $e(t) = r(t) - y(t)$。 PID 的输出控制量 $$u(t)$$ 是由三部分加权相加组成的：
$$u(t) = K_p e(t) + K_i \int_{0}^{t} e(\tau) d\tau + K_d \frac{de(t)}{dt}$$
我们来拆解这三个项：

1.P (Proportional) 比例项 ⚖️：$K_p \cdot e(t)$
- 原理：当前的误差越大，控制力度就越大。就像弹簧一样，拉得越长，回弹力越大。
- 缺点：仅有 P 会产生“静差”（即永远达不到目标点，差那么一点点力）。
2.I (Integral) 积分项 ⏳：$K_i \cdot \int e(t) dt$
- 原理：它会把过去所有的误差“累加”起来。只要误差不为零，积分项就会不断增大，直到消除静差。
- 缺点：积分太强会导致系统反应过慢或产生大幅度震荡。
3.D (Derivative) 微分项 📉：$K_d \cdot \frac{de}{dt}$
- 原理：它测量误差变化的“速度”。如果发现误差正在快速减小，D 项会产生一个反向阻力，防止系统“冲过头”。它起到了预测和阻尼的作用。

Python 项目示例：模拟恒温热水器 ♨️ 为了帮你理解，我们可以用 Python 写一个简单的类。想象你在控制一个热水器，目标是将水温维持在 50°C。

class PIDController:def __init__(self, Kp, Ki, Kd):
        self.Kp = Kp
        self.Ki = Ki
        self.Kd = Kd
        self.prev_error = 0
        self.integral = 0
        def update(self, setpoint, measured_value, dt):# 1. 计算误差
        error = setpoint - measured_value
        
        # 2. P 项
        P = self.Kp * error
        
        # 3. I 项 (积分累加)
        self.integral += error * dt
        I = self.Ki * self.integral
        
        # 4. D 项 (变化率)
        derivative = (error - self.prev_error) / dt
        D = self.Kd * derivative
        
        # 保存误差供下次使用
        self.prev_error = error
        
        # 输出总控制量return P + I + D

MPC

💡 迈向 MPC (模型预测控制) PID 就像是在看后视镜开车：它根据“刚才”和“现在”的偏差来修正。而 MPC 则是看挡风玻璃开车：它拥有一个“车辆模型”，能预测未来 5 秒的轨迹并提前规划。

系统模型 (The Model) 🏎️：MPC 是如何通过数学公式“预知未来”的？（比如：给定现在的油门，1秒后车在哪？）
目标(代价)函数 (Cost Function) 🎯：MPC 怎么定义“什么是好”？（比如：又要快，又要省油，还要乘客坐得舒服，怎么权衡？）
滚动优化 (Receding Horizon) 🔄：为什么 MPC 每一步都要重新计算一次未来的计划，而不是一次跑完？要理解 MPC（模型预测控制），最核心的支柱就是系统模型 (The Model)。如果说 PID 是凭借“直觉”和“经验”在开车，那么 MPC 就是在脑海里装了一个物理仿真器 🏎️。在采取任何行动之前，它都会先在模型里“演练”一遍。什么是系统模型？在控制理论中，模型通常是一组数学方程，它描述了系统的“状态”如何随时间变化。最常用的表达方式是状态空间方程（State-Space Equation）： $$x(k+1) = Ax(k) + Bu(k)$$ 我们可以把这个公式拆解成通俗的语言：

$$x(k+1)$$ (未来状态)：下一时刻系统的样子（比如：下一秒车的位置和速度）。
$$x(k)$$ (当前状态)：现在系统的样子。
$$u(k)$$ (控制输入)：你现在做的动作（比如：踩了多少油门，转了多少度方向盘）。
$$A$$ 和 $B$ (系统参数)：这是模型的“灵魂”，它们代表了物理规律（比如：惯性有多大、摩擦力是多少）。

为什么模型能“预知未来”？有了这个方程，MPC 就可以进行多步预测。想象你在控制一个无人机：

已知：当前的坐标和速度 $x(0)$。
假设：接下来的 3 秒钟，我一直保持 50% 的推力 $u$。
推算：模型会连续计算：

第 1 秒：$x(1) = Ax(0) + Bu$
第 2 秒：$x(2) = Ax(1) + Bu$
第 3 秒：$x(3) = Ax(2) + Bu$ 通过这种方式，MPC 能够看到一段预测时域 (Prediction Horizon) 内的轨迹。

Markdown Extended Features

Wed, 01 May 2024 00:00:00 GMT

GitHub Repository Cards

You can add dynamic cards that link to GitHub repositories, on page load, the repository information is pulled from the GitHub API.

::github{repo="Fabrizz/MMM-OnSpotify"}

Create a GitHub repository card with the code ::github{repo="<owner>/<repo>"}.

::github{repo="saicaca/fuwari"}

Admonitions

Following types of admonitions are supported: note tip important warning caution

:::note Highlights information that users should take into account, even when skimming. :::

:::tip Optional information to help a user be more successful. :::

:::important Crucial information necessary for users to succeed. :::

:::warning Critical content demanding immediate user attention due to potential risks. :::

:::caution Negative potential consequences of an action. :::

Basic Syntax

:::note
Highlights information that users should take into account, even when skimming.
:::

:::tip
Optional information to help a user be more successful.
:::

Custom Titles

The title of the admonition can be customized.

:::note[MY CUSTOM TITLE] This is a note with a custom title. :::

:::note[MY CUSTOM TITLE]
This is a note with a custom title.
:::

GitHub Syntax

[!TIP] The GitHub syntax is also supported.

> [!NOTE]
> The GitHub syntax is also supported.

> [!TIP]
> The GitHub syntax is also supported.

Spoiler

You can add spoilers to your text. The text also supports Markdown syntax.

The content :spoiler[is hidden ayyy]!

The content :spoiler[is hidden **ayyy**]!

Expressive Code Example

Wed, 10 Apr 2024 00:00:00 GMT

Here, we'll explore how code blocks look using Expressive Code. The provided examples are based on the official documentation, which you can refer to for further details.

Expressive Code

Syntax Highlighting

Regular syntax highlighting

console.log('This code is syntax highlighted!')

Rendering ANSI escape sequences

ANSI colors:
- Regular: [31mRed[0m [32mGreen[0m [33mYellow[0m [34mBlue[0m [35mMagenta[0m [36mCyan[0m
- Bold:    [1;31mRed[0m [1;32mGreen[0m [1;33mYellow[0m [1;34mBlue[0m [1;35mMagenta[0m [1;36mCyan[0m
- Dimmed:  [2;31mRed[0m [2;32mGreen[0m [2;33mYellow[0m [2;34mBlue[0m [2;35mMagenta[0m [2;36mCyan[0m

256 colors (showing colors 160-177):
[38;5;160m160 [38;5;161m161 [38;5;162m162 [38;5;163m163 [38;5;164m164 [38;5;165m165[0m
[38;5;166m166 [38;5;167m167 [38;5;168m168 [38;5;169m169 [38;5;170m170 [38;5;171m171[0m
[38;5;172m172 [38;5;173m173 [38;5;174m174 [38;5;175m175 [38;5;176m176 [38;5;177m177[0m

Full RGB colors:
[38;2;34;139;34mForestGreen - RGB(34, 139, 34)[0m

Text formatting: [1mBold[0m [2mDimmed[0m [3mItalic[0m [4mUnderline[0m

Editor & Terminal Frames

Code editor frames

console.log('Title attribute example')

<!-- src/content/index.html -->
<div>File name comment example</div>

Terminal frames

echo "This terminal frame has no title"

Write-Output "This one has a title!"

Overriding frame types

echo "Look ma, no frame!"

# Without overriding, this would be a terminal frame
function Watch-Tail { Get-Content -Tail 20 -Wait $args }
New-Alias tail Watch-Tail

Text & Line Markers

Marking full lines & line ranges

// Line 1 - targeted by line number
// Line 2
// Line 3
// Line 4 - targeted by line number
// Line 5
// Line 6
// Line 7 - targeted by range "7-8"
// Line 8 - targeted by range "7-8"

Selecting line marker types (mark, ins, del)

function demo() {
  console.log('this line is marked as deleted')
  // This line and the next one are marked as inserted
  console.log('this is the second inserted line')

  return 'this line uses the neutral default marker type'
}

Adding labels to line markers

// labeled-line-markers.jsx
<button
  role="button"
  {...props}
  value={value}
  className={buttonClassName}
  disabled={disabled}
  active={active}
>
  {children &&
    !active &&
    (typeof children === 'string' ? <span>{children}</span> : children)}
</button>

Adding long labels on their own lines

// labeled-line-markers.jsx
<button
  role="button"
  {...props}

  value={value}
  className={buttonClassName}

  disabled={disabled}
  active={active}
>

  {children &&
    !active &&
    (typeof children === 'string' ? <span>{children}</span> : children)}
</button>

Using diff-like syntax

+this line will be marked as inserted
-this line will be marked as deleted
this is a regular line

--- a/README.md
+++ b/README.md
@@ -1,3 +1,4 @@
+this is an actual diff file
-all contents will remain unmodified
 no whitespace will be removed either

Combining syntax highlighting with diff-like syntax

  function thisIsJavaScript() {
    // This entire block gets highlighted as JavaScript,
    // and we can still add diff markers to it!
-   console.log('Old code to be removed')
+   console.log('New and shiny code!')
  }

Marking individual text inside lines

function demo() {
  // Mark any given text inside lines
  return 'Multiple matches of the given text are supported';
}

Regular expressions

console.log('The words yes and yep will be marked.')

Escaping forward slashes

echo "Test" > /home/test.txt

Selecting inline marker types (mark, ins, del)

function demo() {
  console.log('These are inserted and deleted marker types');
  // The return statement uses the default marker type
  return true;
}

Word Wrap

Configuring word wrap per block

// Example with wrap
function getLongString() {
  return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

// Example with wrap=false
function getLongString() {
  return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

Configuring indentation of wrapped lines

// Example with preserveIndent (enabled by default)
function getLongString() {
  return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

// Example with preserveIndent=false
function getLongString() {
  return 'This is a very long string that will most probably not fit into the available space unless the container is extremely wide'
}

Collapsible Sections

// All this boilerplate setup code will be collapsed
import { someBoilerplateEngine } from '@example/some-boilerplate'
import { evenMoreBoilerplate } from '@example/even-more-boilerplate'

const engine = someBoilerplateEngine(evenMoreBoilerplate())

// This part of the code will be visible by default
engine.doSomething(1, 2, 3, calcFn)

function calcFn() {
  // You can have multiple collapsed sections
  const a = 1
  const b = 2
  const c = a + b

  // This will remain visible
  console.log(`Calculation result: ${a} + ${b} = ${c}`)
  return c
}

// All this code until the end of the block will be collapsed again
engine.closeConnection()
engine.freeMemory()
engine.shutdown({ reason: 'End of example boilerplate code' })

Line Numbers

Displaying line numbers per block

// This code block will show line numbers
console.log('Greetings from line 2!')
console.log('I am on line 3')

// Line numbers are disabled for this block
console.log('Hello?')
console.log('Sorry, do you know what line I am on?')

Changing the starting line number

console.log('Greetings from line 5!')
console.log('I am on line 6')

Simple Guides for Fuwari

Mon, 01 Apr 2024 00:00:00 GMT

Cover image source: Source

This blog template is built with Astro. For the things that are not mentioned in this guide, you may find the answers in the Astro Docs.

Front-matter of Posts

---
title: My First Blog Post
published: 2023-09-09
description: This is the first post of my new Astro blog.
image: ./cover.jpg
tags: [Foo, Bar]
category: Front-end
draft: false
---

Attribute	Description
`title`	The title of the post.
`published`	The date the post was published.
`description`	A short description of the post. Displayed on index page.
`image`	The cover image path of the post.<br/>1. Start with `http://` or `https://`: Use web image<br/>2. Start with `/`: For image in `public` dir<br/>3. With none of the prefixes: Relative to the markdown file
`tags`	The tags of the post.
`category`	The category of the post.
`draft`	If this post is still a draft, which won't be displayed.

Where to Place the Post Files

Your post files should be placed in src/content/posts/ directory. You can also create sub-directories to better organize your posts and assets.

src/content/posts/
├── post-1.md
└── post-2/
    ├── cover.png
    └── index.md

Markdown Example

Sun, 01 Oct 2023 00:00:00 GMT

An h1 header

Paragraphs are separated by a blank line.

2nd paragraph. Italic, bold, and monospace. Itemized lists look like:

this one
that one
the other one

Note that --- not considering the asterisk --- the actual text content starts at 4-columns in.

Block quotes are written like so.

They can span multiple paragraphs, if you like.

Use 3 dashes for an em-dash. Use 2 dashes for ranges (ex., "it's all in chapters 12--14"). Three dots ... will be converted to an ellipsis. Unicode is supported. ☺

An h2 header

Here's a numbered list:

first item
second item
third item

Note again how the actual text starts at 4 columns in (4 characters from the left side). Here's a code sample:

# Let me re-iterate ...
for i in 1 .. 10 { do-something(i) }

As you probably guessed, indented 4 spaces. By the way, instead of indenting the block, you can use delimited blocks, if you like:

define foobar() {
    print "Welcome to flavor country!";
}

(which makes copying & pasting easier). You can optionally mark the delimited block for Pandoc to syntax highlight it:

import time
# Quick, count to ten!
for i in range(10):
    # (but not *too* quick)
    time.sleep(0.5)
    print i

An h3 header

Now a nested list:

First, get these ingredients:
- carrots
- celery
- lentils
Boil some water.

Dump everything in the pot and follow this algorithm:

 find wooden spoon
 uncover pot
 stir
 cover pot
 balance wooden spoon precariously on pot handle
 wait 10 minutes
 goto first step (or shut off burner when done)

Do not bump wooden spoon or it will fall.

Notice again how text always lines up on 4-space indents (including that last line which continues item 3 above).

Here's a link to a website, to a local doc, and to a section heading in the current doc. Here's a footnote [^1].

[^1]: Footnote text goes here.

Tables can look like this:

size material color

9 leather brown 10 hemp canvas natural 11 glass transparent

Table: Shoes, their sizes, and what they're made of

(The above is the caption for the table.) Pandoc also supports multi-line tables:

keyword text

red Sunsets, apples, and other red or reddish things.

green Leaves, grass, frogs and other things it's not easy being.

A horizontal rule follows.

Here's a definition list:

apples : Good for making applesauce. oranges : Citrus! tomatoes : There's no "e" in tomatoe.

Again, text is indented 4 spaces. (Put a blank line between each term/definition pair to spread things out more.)

Here's a "line block":

| Line one | Line too | Line tree

and images can be specified like so:

Inline math equations go in like so: $\omega = d\phi / dt$. Display math should get its own line and be put in in double-dollarsigns:

$$I = \int \rho R^{2} dV$$

$$ \begin{equation*} \pi =3.1415926535 ;8979323846;2643383279;5028841971;6939937510;5820974944 ;5923078164;0628620899;8628034825;3421170679;\ldots \end{equation*} $$

And note that you can backslash-escape any punctuation characters which you wish to be displayed literally, ex.: `foo`, *bar*, etc.

Include Video in the Posts

Tue, 01 Aug 2023 00:00:00 GMT

Just copy the embed code from YouTube or other platforms, and paste it in the markdown file.

---
title: Include Video in the Post
published: 2023-10-19
// ...
---

<iframe width="100%" height="468" src="https://www.youtube.com/embed/5gIf0_xpFPI?si=N1WTorLKL0uwLsU_" title="YouTube video player" frameborder="0" allowfullscreen></iframe>

YouTube

Bilibili