JPH0358106A - High speed positioning control method - Google Patents

Abstract

PURPOSE:To quickly allow the rotation axis to reach a target position and to suppress the torsional vibration at the time of positioning by feeding back a torsional torque value and a torsional torque differential value in a spring element to a torque command signal to a driving shaft motor. CONSTITUTION:A torque control system 16 inputs an angle signal theta from an angle detecting means 2 of a driving shaft A and a torque command signal gammato a motor 1. Subsequently, an estimated value T1 of a torsional torque value and an estimated value T1 of a torsional torque differential value in a spring element 5 are obtained through an observer means 13. Also, a signal Ka.T1 is obtained through a torsional torque estimated value gain means 15 and a torsional torque differential estimated value gain means 14. Moreover, a motor torque command value gammaa is outputted through an adding means 17a from the signal Ka.T1 and TD.T1. In such a way, the rotation axis reaches quickly a target position, and also, the torsional vibration at the time of positioning is suppressed.

Description

[Detailed Description of the Invention] Industrial Application Fields The present invention is useful for application to, for example, robot arms, cranes, etc. that have spring elements in their joints, positioning tables that have spring elements in their drive parts, etc. This invention relates to a high-speed positioning control method.

BACKGROUND ART In a conventional positioning control method for a rotary shaft having a spring element, only an angular signal and an angular velocity signal are feedback-controlled, as shown in FIG. That is, the drive shaft A of the rotating shaft is constituted by a motor 1, an angle detection means 2, and an angular velocity detection means 3, and outputs a motor angle signal θ and a motor angular velocity signal θ. A load shaft Bit is driven via this drive shaft A spring element 5.

The position gain means 9 receives the angle signal θ and the angle target value signal θ,
The angular deviation signals θ, . , - θ are input, and a signal K. is proportional to this input. (θraf - θ) is output. The speed gain means 10 inputs the speed deviation signal K, (θ21 - θ) - θ obtained through the subtraction means 1lb which performs a subtraction operation between the signal K (θ1, -θ) and the angular velocity signal θ. A torque command signal τ proportional to this input is output.

The torque command signal τ is sent to the drive shaft A via the servo driver 8.
The motor 1 of the motor 1 generates a driving torque. In the end, the position gain means 9, the speed gain means 10, and the subtraction means 11a, l
A position and speed control system 12 is formed by lb, and controls the position and speed of the drive shaft A.

Problems to be Solved by the Invention> By the way, as shown in FIG. 3, in the conventional positioning control method that feeds back only the angle signal θ and the angular velocity signal θ, torsional vibration occurs in the spring element 5 of the rotating shaft during startup and positioning. There is a problem that this occurs and work efficiency deteriorates.

In other words, FIG. 4 shows the time response characteristics of the angle of the load shaft B during positioning control, and as shown in FIG. Since there is no feedback of the torsional torque signal and torsional torque differential signal, torsional vibration occurs and the time required for positioning increases.

In addition, in order to suppress torsional vibration, negative feedback is performed on the torsional torque signal and torsional torque differential signal of the spring element, and when damping is increased at the natural frequency of the rotating shaft, the gain at frequencies above the natural frequency is also reduced. Therefore, positioning can be performed at a speed below the natural frequency, but positioning cannot be performed at a speed above the natural frequency.

Means for Solving the Problems〉 The principle of the present invention for solving the above problems is that, in a rotating shaft in which a drive shaft and a load shaft are coupled by a spring element, an angle detection means and an angular velocity detection means of the drive shaft are used. A position and speed control system that provides negative feedback of the angle signal and angular velocity signal to the torque command signal of the drive shaft motor, and calculates the torsion torque value and torsion torque differential value in the spring element, and calculates the torsion torque value and torsion torque differential value in the spring element, and , the torsional torque estimated value is a negative feedback, and the torsional torque differential value is a torque control system in which negative feedback is given when the positioning frequency is lower than the natural frequency of the rotating shaft, and positive feedback is given when the positioning frequency is higher than the natural frequency of the rotating shaft. It is characterized in that, in addition to the above-mentioned position and speed control that is normally performed, torque control is also performed, thereby making it possible to perform positioning at any positioning frequency.

Function> In addition to conventional position and speed control, torque control is also performed. Torque control involves estimating or measuring the torsional torque value and torsional torque differential value in the spring element. , in response to the torque command signal to the drive shaft motor, the torsional torque estimated value is a negative feed A, and the torsional torque differential estimated value is a negative feedback if the positioning frequency is lower than the natural frequency of the rotating shaft, and the positioning frequency is rotated. If it is higher than the natural frequency of the axis, positive feedback is given.

As a result, when the positioning frequency is lower than the natural frequency of the rotating shaft, the damping corresponding to the natural frequency of the rotating shaft is increased by negative feedback of the estimated torsional torque value and the estimated torsional torque differential value, thereby suppressing the occurrence of torsional vibration. Additionally, if the positioning frequency is higher than the natural frequency of the rotating shaft, negative feedback of the estimated torsional torque increases damping at the natural frequency of the rotating shaft, and
The torsion torque differential estimated value is given positive feedback, and the phase at the positioning frequency is advanced to ensure the desired positioning speed. In this way, the rotating shaft can be positioned at any speed not limited by the natural frequency of the rotating shaft.

Embodiments Here, embodiments of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an overall configuration diagram, and the same parts as in FIG. 3 are given the same reference numerals.

The drive shaft A of the rotating shaft is constituted by a motor 1, its angle detection means 2, and angular velocity detection means 3, each of which outputs a motor angle signal θ and a motor angular velocity signal θ.

The position and speed control system 12 receives an angle signal θ, an angular velocity signal θ, and an angle target value θ1. , is the input. Then, the position gain means 9 generates an angular deviation signal θr* (a signal K.(θ, ., 10) proportional to -6) obtained through a subtraction means 11a that subtracts the angle signal θ and the angle target value signal θ11. The speed gain means 10 outputs the signal K.(θ2
．． , - θ) and the angular velocity signal θ.
The speed deviation signal K.lb is obtained via K.lb. (Outputs .V with a motor torque command value proportional to -C of θ, ., 1.

On the other hand, the torque control system 16 receives the angle signal θ from the angle detection means 2 of the drive shaft A and the torque command signal τ sent to the motor 1 as input.

Then, the estimated torsional torque value in the spring element 5 *T
u and the estimated value TI of the torsional torque differential value are obtained via the observer means 13, and the estimated value TI of the torsional torque differential value K. - Tq and signal T. -T. Adding means 17a from
Motor torque command value τ. Output. In this case, the gain T0 takes a negative value when the positioning frequency is lower than the natural frequency of the rotating shaft, and takes a positive value when the positioning frequency is higher than the natural frequency of the rotating shaft.

Then, the motor torque command value from the position and speed control system 12 is used. 9 and the motor torque command value τ from the torque control system 16
．． The motor torque command value τ obtained by adding τ by the adding means 17b is applied to the servo driver 8. The servo driver 8 causes the motor 1 of the drive shaft A to generate torque.

With this method, when positioning control is performed, the load axis B
The time response of the angle is shown in Figure 2 (al(b)).
As shown in Figure (It) (bl), it can be seen that the target position is quickly reached and torsional vibration during positioning is suppressed even when the positioning frequency is lower than or higher than the natural frequency of the rotating shaft.

In the above embodiment, the torsional torque value and the torsional torque differential value of the spring element 5 were estimated by the observer means 13, but the torsional torque value was directly measured by the torque sensor, and the torsional torque differential value was determined by the torque sensor. It may be estimated based on the torque value.

Effects of the Invention> As explained above in the embodiments, according to the present invention, it is possible to quickly make the rotating shaft reach the target position at any positioning speed, and to suppress torsional vibration during positioning. %Ta.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a control system to which the control method of the present invention is applied, and FIG.
A characteristic diagram showing the time response of the load axis when the Il1 method is executed, Figure 3 is a configuration diagram showing the control system of the conventional technology, and Figure 4 is the time response of the load axis when the conventional control method is executed. FIG. In the drawing, A is the drive shaft of the rotary shaft, B is the load shaft of the rotary shaft, 1 is the motor, 2 is the angle detection means, 3 is the angular velocity detection means, 5 is the spring element, 8 is the servo driver, 9 is the position gain means , 10 is a speed gain means, 11a and llb are subtraction means, 12 is a position speed control system, 13 is an observer means, 14 is a torsional torque differential estimated value gain means, 15 is a torsional torque estimated value gain means, 16 is a torque control system , 7a, 7b are addition means. Mitsubishi Heavy Industries, Ltd

Claims (2)

[Claims] (1) The value of the torque command signal is controlled by controlling a rotating shaft consisting of a drive shaft that rotates according to the value of the torque command signal and a load shaft that is connected to the drive shaft via a spring element and rotates. A control method for positioning a load shaft by determining the position of a load shaft based on an angle signal and an angular velocity signal output from an angle detection means and an angular velocity detection means provided on the drive shaft in response to a torque command signal to the drive shaft. a position and speed control system that performs negative feedback control; and an observer means that receives the angle signal and the torque command signal to the drive shaft to estimate the torsion torque value and the torsion torque differential value at the spring element; In response to the torque command signal, negative feedback control is performed based on the estimated torsional torque value, and
In response to the torque command signal to the drive shaft, if the positioning frequency is lower than the natural frequency of the rotary shaft, negative feedback control is performed based on the estimated torsion torque differential value, and conversely, the positioning frequency is higher than the natural frequency of the rotary shaft. In some cases, it has a torque control system that performs positive feedback control based on the estimated torsional torque differential value, and by performing torque control in addition to position speed control, it is possible to position the load shaft at any positioning frequency. A high-speed positioning control method characterized by: (2) The value of the torque command signal is controlled by controlling a rotating shaft consisting of a drive shaft that rotates according to the value of the torque command signal and a load shaft that is connected to the drive shaft via a spring element and rotates. A control method for positioning a load shaft by determining the position of a load shaft based on an angle signal and an angular velocity signal output from an angle detection means and an angular velocity detection means provided on the drive shaft in response to a torque command signal to the drive shaft. a position and speed control system that performs negative feedback control, and a torque sensor that directly measures the torsional torque value at the spring element, estimates a torsional torque differential value from the measured torque value, and calculates the torsional torque value with respect to the torque command signal to the drive shaft. , Negative feedback control is performed based on the measured torsional torque value, and negative feedback is performed based on the estimated torsional torque differential value when the positioning frequency is lower than the natural frequency of the rotating shaft in response to the torque command signal to the drive shaft. control, and conversely, when the positioning frequency is higher than the natural frequency of the rotating shaft, it has a torque control system that performs positive feedback control based on the estimated torsion torque differential value, and combines torque control in addition to position speed control. A high-speed positioning control method characterized by positioning a load shaft at an arbitrary positioning frequency by performing the following steps.