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Introduce the gait of RaspClaws Robot

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Introduce the gait of RaspClaws Robot

Components used in this course

 

For the hexapod robot, the gait generation method is almost the most complicated part of the program, because it needs to coordinate dozens of servos to move at the same time, and keeps every moment when walking forward and backward there must be at least three legs on the ground, which means that only three legs can be in the swing pair at least at any moment, and at least three legs should be in the support pair.

In order to make it more intuitive, we represent the position of each leg of the robot as 1, 2, 3, 4 respectively and divide the robot legs into two groups. Taking forward heading of the robot as forward direction, we name `I` including the left front leg, the left back leg, and the right middle leg; `II` including the right front leg, the right back leg, and the left middle leg.

Code/Global Gait

1

2

3

4

I

1

2

3

4

II

3

4

1

2

For example, when the first group of legs in the global gait is in the `1` position, the second group of legs is in the `3` position.

When the global gait changes to a cycle of 1, 2, 3, 4, 1, 2, ..., the robot moves forward in a diagonal gait.

When the global gait changes to a cycle of 4, 3, 2, 1, 4, 3, ..., the robot walks backward in a diagonal gait.

When the three legs on the right side of the robot walk forward and the two legs on the left side walk backward, the robot turns to the left.

When the left three legs of the robot walk forward and the left two legs walk backward, the robot turns to the right.

 

 

Introduction of program of gait generation

The code of this course is in move.py. This chapter only introduces the program structure. These codes need to rely on other functions and parameters in move.py to run.

1. #Fast gait    

2. def move(step_input, speed, command):    

3. step_I  = step_input    

4.     step_II = step_input + 2    

5.         

6. if step_II > 4:    

7.         step_II = step_II - 4    

8.     if speed == 0:    

9.         return    

10.     

11.     if command == 'no':    

12. '''''  

13. When the speed is positive, the robot moves forward. When the speed is negative, the robot moves backward.  

14.  '''    

15.         right_I(step_I, speed, 0)    

16.         left_II(step_I, speed, 0)    

17.         right_III(step_I, speed, 0)    

18.     

19.         left_I(step_II, speed, 0)    

20.         right_II(step_II, speed, 0)    

21.         left_III(step_II, speed, 0)    

22.     elif command == 'left':    

23.         right_I(step_I, speed, 0)    

24.         left_II(step_I, -speed, 0)    

25.         right_III(step_I, speed, 0)    

26.     

27.         left_I(step_II, -speed, 0)    

28.         right_II(step_II, speed, 0)    

29.         left_III(step_II, -speed, 0)    

30.     elif command == 'right':    

31.         right_I(step_I, -speed, 0)    

32.         left_II(step_I, speed, 0)    

33.         right_III(step_I, -speed, 0)    

34.     

35.         left_I(step_II, speed, 0)    

36.         right_II(step_II, -speed, 0)    

37.         left_III(step_II, speed, 0)    

38. #Slow gait    

39. def dove(step_input, speed, timeLast, dpi, command):    

40.     step_I  = step_input    

41.     step_II = step_input + 2    

42.     

43.     if step_II > 4:    

44.         step_II = step_II - 4    

45.         

46.     if speed > 0:    

47.         if step_input == 1:    

48.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

49.                 if move_stu and command == 'no':    

50.                     speed_II = speed_I    

51.                     speed_I = speed - speed_I    

52.                     dove_Left_I(-speed_I, 3*speed_II)    

53.                     dove_Right_II(-speed_I, 3*speed_II)    

54.                     dove_Left_III(-speed_I, 3*speed_II)    

55.     

56.                     dove_Right_I(speed_I, -10)    

57.                     dove_Left_II(speed_I, -10)    

58.                     dove_Right_III(speed_I, -10)    

59.                     time.sleep(timeLast/dpi)    

60.                 else:    

61.                     pass    

62.     

63.                 if command == 'left':    

64.                     speed_II = speed_I    

65.                     speed_I = speed - speed_I    

66.                     dove_Left_I(speed_I, 3*speed_II)    

67.                     dove_Right_II(-speed_I, 3*speed_II)    

68.                     dove_Left_III(speed_I, 3*speed_II)    

69.     

70.                     dove_Right_I(speed_I, -10)    

71.                     dove_Left_II(-speed_I, -10)    

72.                     dove_Right_III(speed_I, -10)    

73.                     time.sleep(timeLast/dpi)    

74.                 elif command == 'right':    

75.                     speed_II = speed_I    

76.                     speed_I = speed - speed_I    

77.                     dove_Left_I(-speed_I, 3*speed_II)    

78.                     dove_Right_II(speed_I, 3*speed_II)    

79.                     dove_Left_III(-speed_I, 3*speed_II)    

80.                     dove_Right_I(-speed_I, -10)    

81.                     dove_Left_II(speed_I, -10)    

82.                     dove_Right_III(-speed_I, -10)    

83.                     time.sleep(timeLast/dpi)    

84.                 else:    

85.                     pass    

86.     

87.                 if move_stu == 0 and command == 'no':    

88.                     break    

89.     

90.         elif step_input == 2:    

91.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

92.                 if move_stu and command == 'no':    

93.                     speed_II = speed_I    

94.                     speed_I = speed - speed_I    

95.                     dove_Left_I(speed_II, 3*(speed-speed_II))    

96.                     dove_Right_II(speed_II, 3*(speed-speed_II))    

97.                     dove_Left_III(speed_II, 3*(speed-speed_II))    

98.                     dove_Right_I(-speed_II, -10)    

99.                     dove_Left_II(-speed_II, -10)    

100.                     dove_Right_III(-speed_II, -10)    

101.                     time.sleep(timeLast/dpi)    

102.                 else:    

103.                     pass    

104.     

105.                 if command == 'left':    

106.                     speed_II = speed_I    

107.                     speed_I = speed - speed_I    

108.                     dove_Left_I(-speed_II, 3*(speed-speed_II))    

109.                     dove_Right_II(speed_II, 3*(speed-speed_II))    

110.                     dove_Left_III(-speed_II, 3*(speed-speed_II))    

111.                     dove_Right_I(-speed_II, -10)    

112.                     dove_Left_II(speed_II, -10)    

113.                     dove_Right_III(-speed_II, -10)    

114.                     time.sleep(timeLast/dpi)    

115.                 elif command == 'right':    

116.                     speed_II = speed_I    

117.                     speed_I = speed - speed_I    

118.                     dove_Left_I(speed_II, 3*(speed-speed_II))    

119.                     dove_Right_II(-speed_II, 3*(speed-speed_II))    

120.                     dove_Left_III(speed_II, 3*(speed-speed_II))    

121.                     dove_Right_I(speed_II, -10)    

122.                     dove_Left_II(-speed_II, -10)    

123.                     dove_Right_III(speed_II, -10)    

124.                     time.sleep(timeLast/dpi)    

125.                 else:    

126.                     pass    

127.     

128.                 if move_stu == 0 and command == 'no':    

129.                     break    

130.         elif step_input == 3:    

131.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

132.                 if move_stu and command == 'no':    

133.                     speed_II = speed_I    

134.                     speed_I = speed - speed_I    

135.                     dove_Left_I(speed_I, -10)    

136.                     dove_Right_II(speed_I, -10)    

137.                     dove_Left_III(speed_I, -10)   

138.                     dove_Right_I(-speed_I, 3*speed_II)    

139.                     dove_Left_II(-speed_I, 3*speed_II)    

140.                     dove_Right_III(-speed_I, 3*speed_II)    

141.                     time.sleep(timeLast/dpi)    

142.                 else:    

143.                     pass    

144.     

145.                 if command == 'left':    

146.                     speed_II = speed_I    

147.                     speed_I = speed - speed_I    

148.                     dove_Left_I(-speed_I, -10)    

149.                     dove_Right_II(speed_I, -10)    

150.                     dove_Left_III(-speed_I, -10)    

151.                     dove_Right_I(-speed_I, 3*speed_II)    

152.                     dove_Left_II(speed_I, 3*speed_II)    

153.                     dove_Right_III(-speed_I, 3*speed_II)    

154.                     time.sleep(timeLast/dpi)    

155.                 elif command == 'right':    

156.                     speed_II = speed_I    

157.                     speed_I = speed - speed_I    

158.                     dove_Left_I(speed_I, -10)    

159.                     dove_Right_II(-speed_I, -10)    

160.                     dove_Left_III(speed_I, -10)    

161.                     dove_Right_I(speed_I, 3*speed_II)    

162.                     dove_Left_II(-speed_I, 3*speed_II)    

163.                     dove_Right_III(speed_I, 3*speed_II)    

164.                     time.sleep(timeLast/dpi)    

165.                 else:    

166.                     pass    

167.     

168.                 if move_stu == 0 and command == 'no':    

169.                     break    

170.         elif step_input == 4:    

171.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

172.                 if move_stu and command == 'no':    

173.                     speed_II = speed_I    

174.                     speed_I = speed - speed_I    

175.                     dove_Left_I(-speed_II, -10)    

176.                     dove_Right_II(-speed_II, -10)    

177.                     dove_Left_III(-speed_II, -10)    

178.                     dove_Right_I(speed_II, 3*(speed-speed_II))    

179.                   dove_Left_II(speed_II, 3*(speed-speed_II))    

180.                     dove_Right_III(speed_II, 3*(speed-speed_II))    

181.                     time.sleep(timeLast/dpi)    

182.                 else:    

183.                     pass    

184.     

185.                 if command == 'left':    

186.                     speed_II = speed_I    

187.                     speed_I = speed - speed_I    

188.                     dove_Left_I(speed_II, -10)    

189.                     dove_Right_II(-speed_II, -10)    

190.                     dove_Left_III(speed_II, -10)    

191.                     dove_Right_I(speed_II, 3*(speed-speed_II))    

192.                     dove_Left_II(-speed_II, 3*(speed-speed_II))    

193.                     dove_Right_III(speed_II, 3*(speed-speed_II))    

194.                     time.sleep(timeLast/dpi)    

195.                 elif command == 'right':    

196.                     speed_II = speed_I    

197.                     speed_I = speed - speed_I    

198.                     dove_Left_I(-speed_II, -10)    

199.                     dove_Right_II(speed_II, -10)    

200.                     dove_Left_III(-speed_II, -10)    

201.                     dove_Right_I(-speed_II, 3*(speed-speed_II))    

202.                     dove_Left_II(speed_II, 3*(speed-speed_II))    

203.                     dove_Right_III(-speed_II, 3*(speed-speed_II))    

204.                     time.sleep(timeLast/dpi)    

205.                 else:    

206.                     pass    

207.     

208.                 if move_stu == 0 and command == 'no':    

209.                     break    

210.     else:    

211.         speed = -speed    

212.         if step_input == 1:    

213.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

214.                 if move_stu and command == 'no':    

215.                     speed_II = speed_I    

216.                     speed_I = speed - speed_I    

217.                     dove_Left_I(speed_I, 3*speed_II)    

218.                     dove_Right_II(speed_I, 3*speed_II)    

219.                     dove_Left_III(speed_I, 3*speed_II)    

220.                     dove_Right_I(-speed_I, -10)    

221.                     dove_Left_II(-speed_I, -10)    

222.                     dove_Right_III(-speed_I, -10)    

223.                     time.sleep(timeLast/dpi)    

224.                 else:    

225.                     pass    

226.         elif step_input == 2:    

227.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

228.                 if move_stu and command == 'no':    

229.                     speed_II = speed_I    

230.                     speed_I = speed - speed_I    

231.                     dove_Left_I(-speed_II, 3*(speed-speed_II))    

232.                     dove_Right_II(-speed_II, 3*(speed-speed_II))    

233.                     dove_Left_III(-speed_II, 3*(speed-speed_II))    

234.                     dove_Right_I(speed_II, -10)    

235.                     dove_Left_II(speed_II, -10)    

236.                     dove_Right_III(speed_II, -10)    

237.                     time.sleep(timeLast/dpi)    

238.                 else:    

239.                     pass    

240.         elif step_input == 3:    

241.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

242.                 if move_stu and command == 'no':    

243.                     speed_II = speed_I    

244.                     speed_I = speed - speed_I    

245.                     dove_Left_I(-speed_I, -10)    

246.                     dove_Right_II(-speed_I, -10)    

247.                     dove_Left_III(-speed_I, -10)    

248.                     dove_Right_I(speed_I, 3*speed_II)    

249.                     dove_Left_II(speed_I, 3*speed_II)    

250.                     dove_Right_III(speed_I, 3*speed_II)    

251.                     time.sleep(timeLast/dpi)    

252.                else:    

253.                     pass    

254.         elif step_input == 4:    

255.             for speed_I in range(0, (speed+int(speed/dpi)), int(speed/dpi)):    

256.                 if move_stu and command == 'no':    

257.                     speed_II = speed_I    

258.                     speed_I = speed - speed_I    

259.                     dove_Left_I(speed_II, -10)    

260.                     dove_Right_II(speed_II, -10)    

261.                     dove_Left_III(speed_II, -10)    

262.                     dove_Right_I(-speed_II, 3*(speed-speed_II))    

263.                     dove_Left_II(-speed_II, 3*(speed-speed_II))    

264.                     dove_Right_III(-speed_II, 3*(speed-speed_II))    

265.                     time.sleep(timeLast/dpi)    

266.                 else:    

267.                     Pass