山东科技大学学士学位论文
3.2 micro-bionic foot 6-foot robot trajectory of the identification
Walk in the motion simulation design, if the legs are directly connected in the axis-foot track for the round. This robot's movement will be a half-ups and downs, if he would be able to foot-path in contravention to maintain the formation of the robot can maintain the smooth progress. Besides walking robot requires a strong ability to adapt to the environment, it must be able to print and stability on the steps to walk, and can leap obstacles, Wang ditch, the road to face different trajectory curves have different requirements: the road to the plains require a certain The speed, height requirements and can be lifted over the barrier requirements across the smooth, full-trajectory that the choice of the walking robot, it is very important. Foot-trajectory chosen to be the main consideration of the following questions [3]:
(a) of the high aspect ratio: the ratio of height to width of a direct response to movement of the curve. The greater the ratio of the full trajectory of the higher end, the corresponding level beyond the capacity of the stronger forward at the same time (velocity) on the worse. (b) of length: the width of certain circumstances, the longer the length of curves in the air campaign more time, this will directly affect the speed of the swinging leg, thus affecting the speed of walking. The shorter length curve, the shorter the time to campaign, but the corresponding ability to leap worse. According to walk the walk-demand, initially set foot-movement of the ratio of height to width and length curve, and then use the link on the prior series of patterns [5] (as shown in Figure 3), to find out from the map and
requirements Similar to the trajectory of the curve, and then direct the four bodies found in various size parameters. In this paper, bio-robot designed by the step to 3 mm, the selected used as a robot-foot trajectory of the curve (see figure)
(c) the flat part (that is, at the foot robot movement to end conflict with the part of) the length of about 3 mm, this plane can be identified in all four linkage bar for the length:
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山东科技大学学士学位论文
Crank A = 1mm, link B = 3 mm, Rocker C = 3. 5 mm, fixed-D = 3. 5 mm.
Figure 3： four-link curve map 4 micro-bionic robot triangle gait analysis of the stability
Shown in Figure 4: Point A, B, C respectively, is six foot robot Qiantui the left and right in the leg, left hind legs on the ground of support points. ABC is the triangle support from the three legs posed by a group of support triangle. Robot body from the center to coordinate origin O, Y direction for the robot is the way forward, a strong point A, B, C respectively, the level of coordinates A (xA, yA), B (xB, yB), C (X C, yC), z coordinates of the points are the same, point A ', B', C 'is the robot center of gravity to support each side of the triangle Chuizu points, d1, d2, d3 is the center of gravity to each side of the corresponding The distance.
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山东科技大学学士学位论文
Line AB of the equation:
yA?yBy?(x?xA)?yAxA?xB
Figure 2.3.11 1.30 gait stability margin in terms of plans Slope:
yA?yBKAB?xA?xB
Is a straight line OA 'of the slope
KOA'xA?xB?yB?yA
Its linear equation:
xA?xBy?x , More than two straight AB and OA 'intersection A'
yA?yB
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山东科技大学学士学位论文
The coordinates
?(xAyB?yAxB)(yB?yA)(xAyB?yAxB)(xA?xB)?A?? 22dABdAB??' D2AB in-line AB is the square of distance.
22d?x?y Line OA 'long: 1A'A' Similarly available d2, d3.
Six-legged robot to the Triangle walking gait, their smallest margin stability criterion: d = min (d1, d2, d3)
5 feet 6 micro-bionic robot's drive and control 5.1 micro-six foot bio-robot motor drive circuit
In this paper, the design of micro-bionic six foot robot driver using the Japanese manufacturer of small DC motor drive, control programme using a PC + control box direct control. Motor drive circuit by the serial interface, serial - parallel converters, 74 LS373 latch, DAC0832, integrated operational amplifier component, as shown in Figure 5.
Figure 5： electric drive circuit schematics
Used as a serial data communication lines, will be part of the process control instructions into a series of binary output, a serial - parallel converters for the change required by the parallel digital signal. Digital signal 74 LS373 latch latch, making control signals before the
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山东科技大学学士学位论文
arrival of the next orders to remain unchanged. DAC0832 latch signal as the digital signal input, DAC0832 use of internal computer power standards (± 5V) as a reference power, will convert digital signals to analog signals. In order to ensure the motor-driven power, the analog signal output by adding more computing power amplifier to enlarge the composition of the DC motor to provide the current and voltage used by the DAC0832 analog output voltage direct-drive. At this point, will be controlled from the control signals, the string parallel conversion, digital-to-analog converter, the power amplifier to drive motor, thereby completing the robot movement, the robot's movement direction (forward, back) from the drive voltage Polarity control.
5.2 micro-bionic six foot robot walking speed control
By the formula [6] n = Ua - Ia (Ra + Rtj) / Ce φ motor speed can be seen in three ways: (1) changes in the motor terminal voltage Ua, which is changing armature supply voltage (2) Armature circuit in the serial conditioning resistance Rtj; (3) changes in flux φ.
For the second governor, how to join series resistance Rtj adjustment after the motor speed is always lower than the original, so this method will only speed to a low profile. Also when armature current Ia smaller, Rtj join the resistance after the voltage changes little, motor speed does not change, this method should not be used. The third method for governor, as armature circuit in the electrical time constant larger, this means a certain speed lags behind that of the rapid speed of the poor. In this paper, the robot designed by the first governor methods, controlled by software serial port output to a string of binary DA converters, the DA converted by the electrical voltage needed to operate the DC after the realization of the bio-robot movement control . Different from the binary can be a different voltage, the robot is not the same velocity.
6 feet 6 micro-bionic robot experiment results and analysis
According to the foregoing principles and design, produced a prototype of the bio-robot,
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