Control And Experiment Research In Stepless Adjust Frequency And Amplitude Component Of Vibration Roller

Compaction is applying for in the engineering structure foundation, the dam and roads surface quilt spread. The purpose that the engineering foundation compaction is increase the pressure degree of the soil, improve the loading ability of the road, prevent from sink and the water permeates etc, in order to prevent engineering foundation sink lead to the surface damage at the deadweight and motion load. Compaction the upper layer of the road is acquiring the plane surface and the intensity of shear and intensity of tension, guarantee the vehicle drive is steady. Compaction can raise the engineering anti-permeates and the stability of the climate to guaranteeing the service life of the engineering. The application of the hydraulic and hydraulic control technology has made the adjustment of the vibration parameter possibility. The vibration rollers come true with adjust the frequency and the amplitude, so it is possible to optimize the vibration parameter and real time control the roller. Now some famous roller manufactories are all declare theirs intelligent compactor. Such as the German BOMAG, the German AMMANN, the Sweden DYNAPAC, the American CATERPILLAR and the Japanese SAIKAI etc. The vibrate roller with step less adjust the frequency and the amplitude is the foundation the developing of the intelligent compactor. it is the key parts of the intelligence compactor. There are important meaning to control and experiment researches with it alone. At present, the vibrate compactors are all adopt the single stalk to revolve inertial vibration structure. The vibration structure makes the roller move around. The structure is simple, can be a rotary eccentricity stalk or a rotary eccentricity block. There are many various types. Such as one step amplitude vibration, two step amplitude vibration with add two eccentricity blocks, multi-step amplitude, oscillatory surge vibration etc. But these structure are all step adjust amplitude and can't automatic control. Adjust of the frequency can use the way with pump and motor to complete, it installs and control more convenient than adjust the amplitude.The Xugong Institute Research based on the principle of planet design the step less adjusts the amplitude vibration structure. It can produce direction vibration by change the angle between two eccentricity blocks. And find the rule of this structure how to adjust the amplitude. Horizontal amplitude is a cosine function of the angle between two eccentricity blocks, vertical amplitude is a sine function of that angle. The government patented this structure.The hydraulic control system of this structure is made up with a proportional direction valve and an oscillating grinder with gear track type. With the principle of the PID and PWM, designing the control system with the programmable logic controller as the core, and write the program. This system can adjust the position of the oscillating grinder with the signal from the controller that has been adjusted with PWM. The press oil of this system comes from the vibration system. Because the high press and the low press in the vibration system are alternate, so must to choice with a direction valve. And also because the press of the vibration system is too high, there should be set a reducing valve in this circle. In order to keep the stability of the oscillating grinder, it is must to set a hydraulic lock.The hydraulic control system adjust the frequency is made up with a proportional pump and a motor. When the system is work, the proportional valve in the pump can adjust the displacement of the pump with the signal from the controller. And the motor is work and push the vibration rotation. There are two relief valves to protect the system. There are a charge pump not only recharge the oil to the circle, but also offer a back press to prevent the system did not work under the knock on produce by the high speed rotation or the undulate load, and also provide the pressure for the serve control system. There is a flushing valve in the system. It can be refresh the oil in the circle. It can disperse the heat in the system, and clean the oil.With the principle of the PID and PWM, we design the control system with the programmable logic controller, as the core. The controller is Finland EPEC company 2038 type. The Can line and the PLC are the core for communicate and control. There is display AT3000 in this control system. The controller can receive the signal from every sensor such as angle sensor (coder RSA507 with Can line technology), frequency sensor form vibration motor etc. After that, the controller can calculate those signs and the value given from the display, and send the control signal to the actuator, with it the system work. At the same time the sign send to the Can line, the display receive and display. The program has been compiled. For verifying various functions of this item, there are a completely research in the vibration roller with manufacture a model and build the pedestal for experiments. The experiment's detailed data are recorded with advanced instrument. According to the analysis, get the conclusion hereinafter:This structure can be step less adjust the frequency and amplitude. And the experiment has verifying the rule of adjust the amplitude. The hydraulic control system can do its job. The PLC control system base on PID and PWM after debug is good for the demand in this structure.But there are some problems also: the bearing at the drive position couldn't have right lubrication condition, after work forty hours this bearing damaged without sufficient rubricate. The lubricate condition of the bearing must be improve. The vibration roller center of gravity is deviate to the structure center. This made the amplitude of the roller both ends is not same, this situation is not allow in the jobsite. The hydraulic source of the adjust amplitude is come from the vibration system, from the analysis, this way is not good, it influence the vibration stability. It must change the hydraulic source of the adjust amplitude.Research and manufacture the step less adjust frequency and amplitude structure and the control system is one part work for the intelligence compactor. although the item of the step less adjust frequency and amplitude structure obtained the anticipant result, providing the basis for the next work, but if to develop the intelligence still need the very various research, such as automatic control compaction speed, collect appearance of the compacted material, the match with the vibration parameter, etc, all need to throw in a great deal of energy to study.