Dynamic correction of servo following errors in a computer-numerically
controlled system and fixed cycle utilizing same
    1.
    发明授权
    Dynamic correction of servo following errors in a computer-numerically controlled system and fixed cycle utilizing same 失效
    在计算机数控系统中的伺服跟随误差的动态校正和使用相同的固定循环

    公开(公告)号:US5005135A

    公开(公告)日:1991-04-02

    申请号:US327324

    申请日:1989-03-22

    摘要: The invention relates to servo-driven computer-numerically-controlled systems of the type adapted to receive part program instructions defining a desired path of relative movement between a tool and a workpiece, wherein the path may include an interior or exterior curved portion to be effected by coordinated linear movement of machine members along at least two orthogonal linear axes. The invention provides apparati and methods for correcting path radius errors to facilitate rapid and accurate movement along the curve. In a preferred embodiment, such path radius correction is applied to a fixed cycle for machining inside circles preferably incorporating such path radius correction and providing substantially tangential engagement between the tool and a machining locus orbited by the tool to avoid abrupt accelerations or decelerations while the tool is in contact with the workpiece. In addition to avoiding surface blemishes, this facilitates machining a broader range of hole sizes with a given sized tool thereby reducing the need for frequent tool changes. The invention carries out path radius correction by generating position commands received by the servo using corrected radius data, the difference between which and the desired radius to be machined compensates for at least a portion of the path radius error that would otherwise be generated by the servo. Apparatus and methods for threading holes using a non-helical threading tools with or without path radius correction are also disclosed.

    摘要翻译: 本发明涉及适于接收部件程序指令的伺服驱动的计算机数字控制系统,该程序指令限定了工具和工件之间的相对运动的期望路径,其中该路径可包括要实现的内部或外部弯曲部分 通过沿着至少两个正交线性轴的机器构件的协调线性运动。 本发明提供了用于校正路径半径误差的装置和方法,以促进沿着曲线的快速和准确的移动。 在优选实施例中,将这种路径半径校正应用于用于在圆内进行加工的固定循环,优选地包括这种路径半径校正并且在工具与由工具轨道运动的加工轨迹之间提供基本上切向的接合以避免突然加速或减速,同时工具 与工件接触。 除了避免表面瑕疵之外,这有助于使用给定尺寸的工具加工更宽范围的孔尺寸,从而减少频繁更换刀具的需要。 本发明通过产生由伺服使用校正的半径数据接收的位置命令来执行路径半径校正,其中加工的所需半径和所需半径之间的差补偿由伺服器产生的路径半径误差的至少一部分 。 还公开了使用具有或不具有路径半径校正的非螺旋穿线工具穿孔的装置和方法。

    Interface circuits for electromagnetic position transducers
    2.
    发明授权
    Interface circuits for electromagnetic position transducers 失效
    电磁位置传感器的接口电路

    公开(公告)号:US5164720A

    公开(公告)日:1992-11-17

    申请号:US563480

    申请日:1990-08-06

    IPC分类号: G05D3/12 G08C19/46

    CPC分类号: G08C19/46 G05D3/121

    摘要: Interface circuits for electromagnetic position transducers are provided to reduce the effects of capacitive coupling occurring in the conductive cabling between the position transducers and the associated interfaces located remotely therefrom. Capacitive coupling of excitation signals to the transducer output signals result in error signals appearing as cyclic error in measured positions. The magnitude of the coupled signals are substantially reduced by providing excitation signals symmetrical with respect to ground. The magnitude of the coupled signals are also reduced by presenting equal impedances relative to ground to the output signal return and signal paths. By reducing the effects of capacitively coupled signals, conducting cables for the excitation signals and the transducer output signals may be incorporated in a single shielded cable.

    摘要翻译: 提供用于电磁位置传感器的接口电路,以减少在位置传感器和远程定位传感器之间的导电布线中发生的电容耦合的影响。 激发信号与传感器输出信号的电容耦合会导致误差信号在测量位置上显示为循环误差。 通过提供相对于地面对称的激励信号,大大减少了耦合信号的幅度。 耦合信号的幅度也通过相对于输出信号返回和信号路径的接地相等阻抗而减小。 通过减少电容耦合信号的影响,用于激励信号的传导电缆和换能器输出信号可以并入单个屏蔽电缆中。

    Method and apparatus for position error compensation
    4.
    发明授权
    Method and apparatus for position error compensation 失效
    位置误差补偿方法和装置

    公开(公告)号:US5374883A

    公开(公告)日:1994-12-20

    申请号:US939335

    申请日:1992-09-02

    申请人: Alfred H. Morser

    发明人: Alfred H. Morser

    IPC分类号: G05B19/404 G05B19/21

    摘要: Positioning errors of a moveable machine member are reduced by compensation for cyclic errors attributable to anomalies of a position transducer. Compensation values are produced which are unique only within the pitch of transducer measurement and are applied to correct the representation of measured position produced by the transducer. Positioning errors not attributable to the position transducer are corrected by compensation of position commands using compensation values associated with fixed calibration points. Use of both compensations is effective to eliminate residual errors in position correction which arise from use of calibration data created without correction of transducer cyclic errors.

    摘要翻译: 通过对归因于位置传感器的异常的循环误差的补偿来减少可移动机器构件的定位误差。 产生仅在传感器测量的间距内唯一的补偿值,并且被应用于校正由换能器产生的测量位置的表示。 通过使用与固定校准点相关联的补偿值的位置指令补偿来校正不归因于位置传感器的定位误差。 两种补偿的使用都有效地消除了使用校准数据而产生的位置校正中的残余误差,而无需校正换能器循环误差。

    Method and apparatus for sub-span interpolation
    5.
    发明授权
    Method and apparatus for sub-span interpolation 失效
    用于分段插值的方法和装置

    公开(公告)号:US5229698A

    公开(公告)日:1993-07-20

    申请号:US563366

    申请日:1990-08-06

    IPC分类号: G05B19/4103

    CPC分类号: G05B19/4103

    摘要: A method and apparatus for machine member motion control are provided which reduce position path errors in sampled data motion control systems. Position commands defining locations of a moveable machine member are periodically produced at a predetermined interval as is conventional in sampled data motion control. Intermediate position commands are produced at a predetermined sub-interval less than the predetermined interval in response to a parametric function relating member position and time, the parametric function being continuous through positions defined by the position commands. The intermediate position coordinates are computed as the sum of products of coefficients and coordinates of selected member position commands. To reduce processing time, the coefficients are computed and stored in advance of execution of motion for recall as motion progresses. Where a parabolic function is used to produce intermediate position commands, the sum of products of coefficients and, respectively, past, present and target coordinates are used to compute intermediate positions between the present and target positions.

    Motor control apparatus and method
    6.
    发明授权
    Motor control apparatus and method 失效
    电机控制装置及方法

    公开(公告)号:US5187417A

    公开(公告)日:1993-02-16

    申请号:US770744

    申请日:1991-10-03

    IPC分类号: H02P6/06

    CPC分类号: H02P6/06

    摘要: An apparatus and method for controlling brushless DC motors are provided. Velocity loop control is performed digitally to produce current commands at a high frequency loop closure interval. Commutation of field coil current is controlled in response to current commutation pattern control signals produced in response to measured relative position of the motor rotor and motor stator and a velocity average over a number of loop closure intervals. Switch control signals to control transistor switches providing current from a DC power source to the motor terminals are produced in response to the current commands, measured motor current and the commutation pattern control signals. The velocity loop control implements a selected transfer function relating velocity, the motor torque constant, and the moment of inertia of the motor and associated load. Facilities are provided for periodically adjusting velocity loop transfer function gain factors and the effective moment of inertia in response to input signals. Additionally, current loop amplification gain factors and time constants are made selectable by input signals.

    摘要翻译: 提供一种用于控制无刷直流电动机的装置和方法。 以数字方式执行速度环控制,以在高频闭环间隔产生电流指令。 响应于响应于电动机转子和电动机定子的测量的相对位置产生的电流换向模式控制信号以及在多个闭环间隔上的速度平均值来控制励磁线圈电流的换向。 响应于电流指令,测量的电动机电流和换向模式控制信号,产生开关控制信号以控制提供从直流电源到电动机端子的电流的晶体管开关。 速度环控制实现与速度,电动机转矩常数以及电动机和相关负载的转动惯量相关的传递函数。 提供设施,用于周期性调整速度环路传递函数增益因子和响应于输入信号的有效转动惯量。 此外,电流环路放大增益因子和时间常数可由输入信号选择。

    DC Servomotor circuit having drive current controlled as a function of
motor speed
    7.
    发明授权
    DC Servomotor circuit having drive current controlled as a function of motor speed 失效
    直流伺服电机具有作为电机速度的函数的驱动电流

    公开(公告)号:US4302711A

    公开(公告)日:1981-11-24

    申请号:US14980

    申请日:1979-02-26

    IPC分类号: H02P7/00 H02P7/292 H02P5/16

    CPC分类号: H02P7/293 H02P7/05

    摘要: A drive circuit is provided for controlling the energization of a DC motor as a function of speed to maintain the motor speed equal to a speed defined by a speed command signal. The speed command signal is summed with a velocity feedback signal to produce a speed error signal which is used as an input to a motor drive circuit. In accordance with the invention, the speed error signal is limited in order to continuously limit the current through the motor to a continuously changing maximum depending on the speed of the motor. During an initial part of the speed range, the limiting level is increased to maintain a constant maximum motor current. During an intermediate speed range, the limiting level decreases so as to sharply decrease current with increasing motor speed; and during a final speed range, the limiting level increases so as to gradually decrease current with increasing motor speed.

    摘要翻译: 驱动电路用于控制作为速度的函数的直流电动机的通电,以将电动机速度维持在速度指令信号所限定的速度上。 速度指令信号与速度反馈信号相加,以产生用作电动机驱动电路的输入的速度误差信号。 根据本发明,速度误差信号被限制,以便根据电动机的速度将电动机的电流连续地限制到连续变化的最大值。 在速度范围的初始部分,增加限制水平以保持恒定的最大电动机电流。 在中间速度范围内,极限电平降低,从而随电动机转速的增加急剧减小电流; 并且在最终速度范围内,限制水平增加,随着电机速度的增加逐渐减小电流。