【正文】 為解決這個(gè)問題 ,就要求各坐標(biāo)軸間相互傳送信息。首先調(diào)查對(duì) 稱交叉耦合 (SCC)控制 ,不幸的是它不能良好的同時(shí)減少誤差。在文獻(xiàn)中這個(gè)問題沒有得到解決。要同時(shí)控制誤差 ,常規(guī)誤差范圍和深度誤差 ,就需要有新的策略 ,這是因?yàn)榭刂浦行牡臉?biāo)準(zhǔn)算法不能直接使用。這個(gè)誤差影響工件表面的完成質(zhì)量。然而 ,在非正交 RMT內(nèi)的表面切削同時(shí)要求三軸坐標(biāo)。但是，所有這些方法都不用于非正交軸線機(jī)床。另一種克服形狀高饋送率這個(gè)問題的方法 ,是用適應(yīng)的饋送率控制策略 ,以提高控制性能。先進(jìn)的控制方法已應(yīng)用于使原有交叉耦合控制 (CCC)的控制性能更進(jìn)一步提高。每 次采樣時(shí)，交叉耦合控制計(jì)算當(dāng)前形狀誤差 ,并產(chǎn)生指導(dǎo)刀具沿著預(yù)定軌跡運(yùn)動(dòng)的指令。其他方法是使用交叉耦合控制實(shí)驗(yàn)中移動(dòng)軸共享的反饋信息。第一種方式是使用前饋控制 ,以減少實(shí)驗(yàn)跟蹤誤差。為了減少造型錯(cuò)誤 ,即指在預(yù)定的和實(shí)際的軌跡。 做等直線運(yùn)動(dòng)的要求規(guī)定刀具要沿著理想的軌跡運(yùn)動(dòng)。這篇文章主要是描述原型非正交多軸 RMT 機(jī)床。這種機(jī)床使 ERC 研究中心的研究人員機(jī)床設(shè)計(jì) 和驗(yàn)證方法得到了發(fā)展。典型的 RMS 一般包括傳統(tǒng)的和可重組的新型數(shù)控機(jī)床。與這兩個(gè)極端相比 ,Koren 描述了一種要求可重組設(shè)計(jì)制造制造系統(tǒng) (RMS)的新辦法。 DMS 是一個(gè)理想的在設(shè)計(jì)、量產(chǎn)定需降低成本時(shí)的解決方法。此外 ,它顯示了非對(duì)稱交叉耦合前饋(NSCCFF)控制顯示最好成績(jī)是主要的概念和非正交機(jī)床?？刂葡到y(tǒng)的穩(wěn)定性調(diào)查 ,使用模擬比較不同類型控制。這項(xiàng)研究的重點(diǎn)是減少新型交叉耦合控制的非正交機(jī)床形狀和加工誤差的概念設(shè)計(jì)。當(dāng)機(jī)械軸非正交時(shí)，軸線之間的運(yùn)動(dòng)必須是緊密結(jié)合，各運(yùn)動(dòng)軸協(xié)調(diào)的重要性變得更大。這篇文章 ,涉及一類新的非正交可重組機(jī)床 (RMTs)。誤差的范圍是指與刀具實(shí)際預(yù)定軌跡的距離。 非正交可重組機(jī)床的控制 摘要 為了準(zhǔn)確預(yù)定刀具相對(duì)于工件的軌跡，機(jī)床計(jì)算機(jī)控制系統(tǒng)必須協(xié)調(diào)各運(yùn)動(dòng)機(jī)構(gòu)運(yùn)轉(zhuǎn)軸的動(dòng)作。 [6] Ulsoy AG, Koren Y. Control of machining processes. ASME J Dyn Syst Meas Control 1993 [8] Park J, Ulsoy A. Online tool wear estimation using force measure ment and a nonlinear observer. ASME J Dyn Sys Meas Control 1992 [9] Glass K, Colbaugh R. Realtime tool wear estimation using cutting force measurements. In: Proceedings of the 1996 IEEE international conference on robotics and automation。, is shown in Fig. 7. The stability analysis results may be summarized as follows: 1 The stable region for SCC and SCCFF controllers is an area bounded by three lines (as shown in Fig. 7): Line 1, Line 2, and Line 3 while the stable region for NSCCFF controller is the area bounded by Line 1 and Line 3. 2 For higher values of the gain Wz, Line 2 moved to the left while Line 1 and Line 3 were not affected by varying Wz. It means that a higher value of the proportional controller gain Wz, will reduce the stability region. 3 For higher values, Line 2 moves to the right while Line 1 and Line 3 are not affected. However, Line 2 can never cross Line 3 by only varying . The meaning of this observation is that horizontal spindle position represents better stability of the system. 4 The stability region bees smaller with increasing sampling period. The system with the NSCCFF controller has the largest stable region for WP, WI, and WZ. This is due to the fact that the conflict between the crosscoupling controllers has been removed by decreasing the indepth error by Zaxis movement only. The conflict between the crosscoupling controller in SCC and SCCFF controller can be seen in the transfer function shown in Eqs. (4) and (5). The subsystem for the contour error, which consists of X and Yaxis only, should contain only variables related to the X and Yaxis such as Ex, Ey, Xr, and Yr. However, this subsystem contains also an Ez term. This Ez term will act as a disturbance to the contour subsystem. Similarly, the subsystem for the indepth error, which consists of Y and Zaxis only, should be posed of terms related to the Y and Zaxis. Again, the indepth subsystem contains an Ex term which will act as a disturbance to this subsystem. Unlike the transfer function of the Zaxis in Eq. (4), the one in Eq. (5) contains a feedforward term Kff. This Kff reduces the disturbance to the system resulting in a better performance for the SCCFF than the SCC controller. Considering the transfer functions for the NSCCFF controller shown in Eq. (6), the subsystem for the contour error contains only terms related to the X and Yaxis and the subsystem for the indepth error contains a feedforward term Kff that pensates the disturbance term. In other words, the disturbance term from the contour crosscoupling controller to the indepth crosscoupling controller was removed using the feedforward term. Also the disturbance term from the indepth crosscoupling controller to the contour crosscoupling controller was removed by correcting the indepth error by only moving the Zaxis. Overall, the performance of the system using NSCCFF controller is expected to be the best among the proposed controllers, and the simulation results support this analysis. 5 Simulation Results The simplified RMT axial model that was used in the simulation (the parameters for each axis can be found in appendix A). The crosscoupling controller parameters were chosen such that the system will operate within the stable region defined in the previous section. These parameters are not the optimal since optimization of the controller, was not a goal of this paper. For parison purposes, all crosscoupling controller parameters are kept the same throughout the simulation. The desired tool path is a circular motion on the inclined XS plane, and the response of each controller to a disturbance is pared. 6 Conclusions The conceptual design process of crossedcoupling controllers that was described in the paper allows insight and better understanding of the RMT controller problem. Some machining processes that traditionally require four or 5 degreesoffreedom using an orthogonal CNC machine, may be performed by a new machinetype—the reconfigurable machine tool (RMT) that has just threedegrees of freedom. The disadvantage of the RMT configuration is that when contour cuts are needed in the XS plane, a new type of error—the indepth error—may occur. This error, if not controlled properly, may severely affect the surface finish of the machined surfaces. To reduce the effect of the indepth error, we introduced three types of crosscoupling controllers and found that all three are stable for a reasonable range of parameters. An increase of the reconfiguration angle (or toolpositioning angle) increases the contour and indepth errors and decreases the region of stability. Furthermore, we also found that all three types of