A Robot Dog You Can Built at Home — Transcript

Full transcript

1. 0:04In my last video, I gave you guys a
2. 0:05sneak peek for the four-legged version
3. 0:07of my previous robot, which had six
4. 0:08legs. And now the training legs are
5. 0:11finally off. Say hello to Quattro ZBD, a
6. 0:143D printed robot dog. You can build at
7. 0:16home, train in simulations, and test in
8. 0:18real world. This robot is fully open
9. 0:21source and free. You can download the
10. 0:23designs and scripts, print it in your 3D
11. 0:25printer, or order them from an online
12. 0:27printing service. Put the parts together
13. 0:29and start experimenting on your own. You
14. 0:32can even puppeteer it with your under it
15. 0:33phone to give it lielike reactions to
16. 0:35its surroundings. Quarter ZVD can be
17. 0:38controlled with any Bluetooth controller
18. 0:39or its companion mobile controller app.
19. 0:42You don't need to be a programmer to
20. 0:43make it all work either. Since you can
21. 0:45adjust most of its settings via the
22. 0:47onboard screen, just download and flash
23. 0:49the scripts to ESP32, connect your
24. 0:52Bluetooth controller, and fire up. I
25. 0:55know it looks a lot like its older
26. 0:57sibling and I will tell you exactly what
27. 0:59changed in detail. But let's start with
28. 1:01the most important one, the cost. By
29. 1:03removing two legs, I managed to bring
30. 1:05the total cost of the building robot
31. 1:07down to roughly 200 USD with all
32. 1:10electronics included, of course. The
33. 1:12exact figure might change depending on
34. 1:14where you live in the world or where to
35. 1:16order your parts, but it's safe to say
36. 1:18the cost reduction should make it
37. 1:20affordable to more people. Going from
38. 1:23six legs to four isn't just a matter of
39. 1:25taking two legs out and reducing build
40. 1:27cost. With four legs, every step changes
41. 1:30the robot's support configuration much
42. 1:32more dramatically. That makes balance,
43. 1:34timing, and gate planning considerably
44. 1:37more important. And yet, compared to its
45. 1:40six-legged older sibling, Quattro ZBD is
46. 1:42definitely lighter, more agile, and
47. 1:45faster. Now, when I say faster, it's not
48. 1:48an Olympic sprinter, of course, but it's
49. 1:50a learning platform after all. and I'm
50. 1:52quite happy with its performance as it
51. 1:54feels much zappier when walking it
52. 1:56around the house. So, let me walk you
53. 1:58through the minor structural redesigns,
54. 2:00power layout changes, and broadly guide
55. 2:02you through how you can build your own
56. 2:04robot dog.
57. 2:07Quattro ZBD still uses the same designs
58. 2:09for majority of its parts as hexod.
59. 2:12Therefore, each part is still designed
60. 2:14to be easily 3D printed and can be
61. 2:16easily modified to accommodate
62. 2:18additional parts and sensors if needed.
63. 2:21As I mentioned in my previous videos, my
64. 2:23goal for this project is to create a
65. 2:25modular DIY robotics development
66. 2:27platform that can be used for different
67. 2:29modes of locomotion and terrain
68. 2:31traversal methods. Using the same parts
69. 2:34allows easy interchangeability between
70. 2:36the six-legged and four-legged
71. 2:37configurations. I even plan to maintain
72. 2:40this modularity for my future revisions
73. 2:42of the robot that may use wheels or even
74. 2:44tracks for traversing rough terrain.
75. 2:47Before we get deep into technical
76. 2:48aspects, I have to confess something
77. 2:50first. The reason for the new shortened
78. 2:53main body is entirely for my aesthetic
79. 2:55pleasure. Four legs on the old lumber
80. 2:57main body looked a bit odd. I could
81. 3:00increase the length of the legs, but
82. 3:02that would require more powerful soros.
83. 3:04Eventually, I did not want the robot to
84. 3:07look like an oversized wiener dog. I
85. 3:09prefer my dogs a bit more well
86. 3:11proportioned, so I decided to shorten
87. 3:13the body length instead. I hope most of
88. 3:16you will agree with me on this one.
89. 3:17However, if you're a Dashan breed fan or
90. 3:20simply prefer the longer main body, you
91. 3:22can still use the new scripts on the old
92. 3:24design without the middle legs and as
93. 3:26long as you apply the new wiring diagram
94. 3:28for the electronics as well. The top
95. 3:30covers are still the main source of the
96. 3:32structure of integrity to prevent main
97. 3:34body from flexing when the robot is
98. 3:36walking. The only difference here is the
99. 3:38PCA board is now mounted to the middle
100. 3:40top cover. I did not want the smaller
101. 3:42size of the robot to take away from any
102. 3:44of its capabilities. So, in order to
103. 3:46keep the IMU sensor in, which enables
104. 3:49the robot to balance on its own, I
105. 3:51placed the PCA board under the middle
106. 3:53top cover plate to leave room for the
107. 3:55IMU board in the middle section nearest
108. 3:57to the robot's center of mass. As for
109. 4:00resilience measures, I kept my unique
110. 4:02handscent failsafe mechanism. Instead of
111. 4:05using metal servo horns, the servo heads
112. 4:07mount directly to the 3D printed plastic
113. 4:10parts. If the robot falls hard, the
114. 4:12tenscent plastic part strips before
115. 4:14breaking the metal servo gears. I highly
116. 4:17recommend this method as I have been
117. 4:19testing my robots with the same set of
118. 4:2018 servos for months now and despite
119. 4:23some epic falls, I haven't lost any
120. 4:25servo yet. Another failsafe mechanism is
121. 4:28embedded in the rails that connect the
122. 4:30hip clamps to the main body. Now, they
123. 4:33might look flimsy, but I assure you they
124. 4:35are strong enough to keep the legs
125. 4:36attached to main body under normal
126. 4:38operation of the robot. I never had any
127. 4:41of these parts break without robot
128. 4:42falling from heights in an accidental
129. 4:45fall. The rails are designed to snap
130. 4:47before breaking the main body, making
131. 4:49the repairs costless and consume less
132. 4:51time to fix given all the electronic
133. 4:53parts are attached to the main body.
134. 4:55This is also proven under carefully
135. 4:57designed testing conditions.
136. 5:00For power management, four legs mean a
137. 5:03significantly cleaner power grid.
138. 5:05Quattro ZBD only needs one PCA board to
139. 5:08accommodate its 12 servos. Same as
140. 5:10before, only signal wires for servos are
141. 5:13connected to the PCA board. They receive
142. 5:15their power directly from their
143. 5:17dedicated buck converter for each pair
144. 5:19of links. There is still a dedicated
145. 5:21buck converter for ESP32 to isolate
146. 5:24communication from main power rail to
147. 5:26prevent brownouts and signal degradation
148. 5:29from noise. I don't use custom PCBs or
149. 5:32power distribution boards for my robots.
150. 5:34Instead, I use survey extension cables
151. 5:36that merge signal wires for each leg
152. 5:38into a single header and connect the
153. 5:40power cables directly to the buck
154. 5:42converters. The rest of the assembly is
155. 5:44also very beginner friendly and uses
156. 5:46simple parts like a twoin four out vego
157. 5:48connector for the main battery power
158. 5:50distribution. IMU is daisy chain to the
159. 5:53PCA board and there's a screen directly
160. 5:56connected to the ESP 32 making the
161. 5:58entire setup straightforward to wire
162. 6:00rock and without any soldering needed.
163. 6:02You can find the entire wiring diagram
164. 6:04down in the description, which should
165. 6:06allow you to replicate my setup in under
166. 6:08a couple of hours.
167. 6:11A quadruped walking gate requires
168. 6:13dynamic balance. Since the structure of
169. 6:15the legs remain identical between the
170. 6:17two different versions of the robot, I
171. 6:20adjusted the kinematics code to output a
172. 6:22four-legg gate using the same inverse
173. 6:24kinematics solver we used on the
174. 6:26previous sixlegged version of the robot.
175. 6:29Once I adjusted the gate mechanism to
176. 6:31four legs, the rest of the script was
177. 6:33almost already done because all the
178. 6:35features I developed for Hexodox ZBD
179. 6:38carry it right over to Quattro ZBD.
180. 6:41Quattro ZBD still features body
181. 6:43leveling, which lets the robot
182. 6:45compensate for uneven ground or inclined
183. 6:47surfaces by keeping the robot's body
184. 6:48orientation relatively stable. Body
185. 6:51height and pitch control give users the
186. 6:53freedom to control and adjust the
187. 6:55robot's main body independently.
188. 6:57Idle breathing animation prevent the
189. 6:59robot from looking like a frozen statue
190. 7:01when it's left idle, giving it a lielike
191. 7:04impression.
192. 7:06And of course, my favorite, the puppet
193. 7:08mode, a unique feature of my robots
194. 7:10through which you can puppeteer the
195. 7:12robot with your own mobile phone. This
196. 7:14was an accidental discovery for me. I
197. 7:17came up with this idea when I was
198. 7:18testing an IMU sensor connected to the
199. 7:20simulation version of the robot on my
200. 7:22PC. As I was moving the IMU board on a
201. 7:25small plane, I realized I could use the
202. 7:27gyro sensor on my phone to control the
203. 7:29pitch, tilt, and yaw of the robot's main
204. 7:32body. I immediately put my idea to test
205. 7:34on the real robot, and it turned out to
206. 7:36be my favorite feature yet because it
207. 7:38brings the robot to life and appear to
208. 7:40react its surroundings with highly
209. 7:42responsive movements. Unfortunately,
210. 7:44this feature is only available if you
211. 7:46control the robot with the companion
212. 7:48Android controller app, as it relies on
213. 7:50the mobile phone's gyro sensor.
214. 7:52Not every feature from Hexodoc carried
215. 7:54over to Quattro. We still have
216. 7:56pre-programmed emotes to make the robot
217. 7:58dance. But since Quadro doesn't have six
218. 8:00legs, the number of preconfigured emotes
219. 8:03are reduced as some of the old emotes
220. 8:05relied on the extra two legs. So, I'm
221. 8:08sorry to report we no longer have the
222. 8:10angry Italian robot emote.
223. 8:12As for other customizations, majority of
224. 8:15the robot settings and calibrations can
225. 8:17be done via the menu I created for its
226. 8:19onboard screen, including changing the
227. 8:22shape and color of the robot's animated
228. 8:24eyes for further personalization.
229. 8:27Now, let's talk about the way it works.
230. 8:30Well, as mentioned earlier, Quattro is
231. 8:32noticeably lighter, faster, and much
232. 8:34more responsive. I optimized the gates
233. 8:36for slightly lower step up because with
234. 8:39previous robot I also wanted to see the
235. 8:41limits of my design out in the streets
236. 8:43where the pavement is not always flat.
237. 8:46Quattro however is more of an indoors
238. 8:48robot and reduced step height enable
239. 8:50higher walking speeds due to less body
240. 8:52shift during faster gate cycles. It
241. 8:55definitely received some second child
242. 8:57treatment here because with my first
243. 8:59robot, I was almost obsessed with
244. 9:01getting the foot clean off the ground
245. 9:02walking and I wanted to show off by
246. 9:04making sure the step height was high
247. 9:06enough to be clearly visible from all
248. 9:08angles. With Quadro ZBD, I mostly
249. 9:11focused on faster and stable walking
250. 9:13instead of higher step heights.
251. 9:18Another addition to gate mechanism is
252. 9:20walking it. Quattro ZVD can use two
253. 9:22different walking styles. First of which
254. 9:24is stroke kick where two diagonal legs
255. 9:27always stay on the ground while the
256. 9:29other two legs are in the air. The
257. 9:31second style is walking where three legs
258. 9:34remain on the ground while only one leg
259. 9:36is in the air. Walk gate is slower
260. 9:38compared to throwing but I added some
261. 9:40extra wide hip swings during the gate
262. 9:42cycle. So it has a bit more style and
263. 9:44swag compared to more mechanical style
264. 9:47of thro gate. My optimized parameters
265. 9:49for each gate type are already included
266. 9:51in the shared ESP territory script. But
267. 9:54if you wish to customize the way the
268. 9:55robot works, subscribe to the channel
269. 9:57for future tutorial videos where I show
270. 9:59how to optimize gates in Pybullet and
271. 10:02Isaac simulations.
272. 10:04Quattro ZBD uses a single 3S 3000 mAh
273. 10:07battery. And with this battery, I get
274. 10:10consistent run times above 20 minutes.
275. 10:13Considering I don't plan on committing
276. 10:15the robot to extensive survey missions
277. 10:17out in the fields, it's enough for my
278. 10:19purposes. If you want longer play times,
279. 10:21Quattro can accommodate larger battery
280. 10:23packs for longer run times. So, can you
281. 10:26build a robot for $200? Yes, but you
282. 10:30have to keep in mind you're not buying a
283. 10:31finished robot. You are building a
284. 10:33robotics development platform. And
285. 10:35that's exactly what makes Quattro
286. 10:37interest. It's affordable enough to
287. 10:39experiment with, open enough to modify,
288. 10:41and capable enough that you can take the
289. 10:43same concepts from simulations to the
290. 10:45real world. If you want to build Quadra
291. 10:47yourself, all 3D print files, assembly
292. 10:50guides, wiring schemes, and ESP32 codes
293. 10:53are 100% open source and linked down in
294. 10:55the description below. If you also
295. 10:57interested in the sixlike version of the
296. 10:59robot, you can watch the previous videos
297. 11:01on my channel and find all the links for
298. 11:03its design files and scripts in the
299. 11:05descriptions of those related videos.
300. 11:07Thank you all so much for the support on
301. 11:09the channel over the past few months. If
302. 11:11you enjoyed this build, hit the like
303. 11:13button and subscribe the channel. Make
304. 11:15sure to let me know in the comments what
305. 11:16you think of Quattro ZVD. Thank you so
306. 11:19much.