34results about How to "Control output speed" patented technology

The invention discloses a device and a method for preparing particulate-reinforced aluminum matrix composites by stirring and casting. The device comprises a lifting mechanism, a resistance furnace, a fixed column, a supporting mechanism, a stirring device, a particulate conveying device, a furnace lid, a feeding hole, a gas inlet tube, a graphite crucible and a stainless steel crucible. The device for preparing particulate-reinforced aluminum matrix composites by stirring and casting can be used for quantitatively conveying and adding reinforced particulates, and realizing gas protection and automatic preparation. The device is delicate in structural design, simple and convenient to operate, high in automation degree and good in stability. By virtue of the gas protection, gas absorption and surface oxidization of a melt in a preparation process based on stirring and casting are reduced; the quantitative conveying and adding of the reinforced particulates are realized by virtue of the particulate conveying device; the quantitative control on a stirring position and a stirring speed is realized by virtue of the lifting device and the stirring device, and thus, the performance and preparation efficiency of a composite material are well improved.

The invention provides a variable-pitch shape memory alloy rotary motor. The rotary motor uses a shape memory alloy helix as a drive element, one end of the shape memory alloy helix is connected with an output shaft through a given screw, the other end of the shape memory alloy helix is connected with a motor base through a fixing clamp, and the output shaft is fixed on the motor base through a bearing. The shape memory alloy helix is shaped at high temperature to form a pitch-diameter large-sized helix and is processed at low temperature to form a pitch-diameter small-sized helix and then installed in the motor, and the helix at the high temperature and the helix at the low temperature are identical in height. After a power supply is switched on, the shape memory alloy helix restores to the pitch-diameter large-sized helix at the high temperature due to the shape memory effect and drives the output shaft to perform rotary motion so as to output torque and a rotating angle, but the output shaft does not displaces axially. The variable-pitch shape memory alloy rotary motor is simple in structure, convenient to control, large in power density and high in energy utilization efficiency and can serve as a discontinuously-rotating power device definite in torque and rotating angle.

The invention provides a servo control method for the gasoline engine speed in a hydraulic system of a legged robot. The servo control method comprises the following steps: (1) calculating the engine speed error e and the engine speed error change rate ec; (2), after the fuzzy logic calculation of e and ec, outputting the proportionality coefficient increment delta kp and the integral coefficient increment delta ki; (3) calculating the proportionality coefficient and the integral coefficient according to the following formulas correspondingly: kp = kp0 + delta kp and ki = ki0 + delta ki; (4) calculating the accelerator opening degree according to the following formula: S1 = S1_old + kp*ec + ki*e; (5) calculating the accelerator opening degree change caused by the hydraulic oil flow rate change according to the following formula: S2 = kQ*detal Q; and (6) calculating the final accelerator opening degree Sf = S1 + S2, wherein the rotation of a steering engine is controlled through the accelerator opening degree in the PWM form, the air inlet volume is controlled by controlling the opening degree of an engine throttle valve through an accelerator cable, and finally the engine speed is controlled. The servo control method provided by the invention has the advantages that the feedforward control is adopted, so that the stable engine speed can be guaranteed well under the circumstance that the flow rate changes suddenly; parameters are modified online by adoption of fuzzy self-tuning, so that the different control requirements can be met; and accordingly, the hydraulic system can have the good dynamic property and static property.