JPS62120514A - Position control drive method - Google Patents

Abstract

PURPOSE:To attain the high-speed drive and to secure the position accuracy in a stop or low-speed drive mode by using two drive systems with the action of a single degree of freedom and setting a phase difference between both drive systems. CONSTITUTION:The reference positions of two rotational angle position sensors 13 and 23 are set at N=0 and M=0 respectively. Under such conditions, it is supposed that both reduction gears 11 and 21 have backlashes. When motors 10 and 20 have minute rotations so as to satisfy N=+p1 and M=-p1 respective ly, it is possible to have p1 rotations so that the backlashes produced up to a gear 30 are deleted. Then both motors 10 and 20 are revolved up to N=p1+alpha and M=-p1-alpha respectively and therefore both gears 11 and 12 have minute elastic twists. Thus the drive positions of both motors are shifted and can be selected in a state where both gears 11 and 21 are controlled to the satisfacto rily small backlashes or some elastic pilot pressure is applied. As a result, the high-speed drive is possible by setting a phase difference between two drive systems and the position accuracy is secured in a stop or low-speed drive mode.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a position control driving method for transmitting the driving force of an Fi driving body to a driven body via a power transmission mechanism.

B9 Summary of the Invention The present invention is an operating device that requires position control drive, in which only the final output shaft or joint shaft is free from backlash or play, and two prime movers and a reducer or link are required to operate the shaft. A drive system with normal backlash is constructed with two series, and the two series are controlled by servo using a position sensor in each drive part.The load on the joint, The two systems of drive can be adjusted with a phase difference as appropriate depending on conditions such as speed.

0. Problems to be solved by the invention In order to achieve accuracy in a drive device that controls position or rotational angle position, play and backlash in the drive system, such as a reduction gear or a link, must be extremely minimized to achieve accuracy. Driving with good position control was not possible. Therefore, in order to eliminate backlash, υ backlash was removed using a preload mechanism, etc., but this created a large frictional resistance during operation, making it impossible to perform fine movement and reducing position accuracy. I couldn't get enough of it.

In particular, in manipulators that require good force sensation, even if frictional resistance is not required in the power transmission mechanism, deceleration mechanism, etc., backlash can cause oscillations when increasing the gain of the control system for high drive. It was easy.

Means and Function for Solving the Problems In view of the above-mentioned problems, the present invention performs deviation processing on the first position detection signal of the drive system and the position command signal corresponding to the driven object to determine the first deviation. obtain the first deviation signal, and use the first deviation signal to obtain the first deviation signal.
a first drive system that controls a drive source; a calculation signal is obtained by calculating the position command signal and the phase difference command signal; and a deviation processing of the calculation signal and a second position detection signal is performed to obtain a second deviation. A second drive system that obtains a signal and controls a second drive source using the second deviation signal drives and controls a driven system having one degree of freedom.

Further, the present invention performs deviation processing on the first position detection signal of the drive system and the position command signal corresponding to the driven object to obtain a first deviation signal, and uses the first deviation signal to control the first drive source. a first drive system to be controlled; a phase difference command signal is obtained from the first deviation signal; and a second deviation signal is obtained by processing the phase difference command signal and the position command signal; 1 by the second drive system that controls the second drive source using the deviation signal of
Drive control of the driven system with degrees of freedom.

E. EXAMPLES The present invention will be specifically explained below using examples shown in FIGS. 1 to 5.

The present invention relates to a driving method for driving one driven part using two driving engines. As shown in FIG. 5, motors 10 and 20 are used as drive engines. Power is transmitted to each motor in parallel using appropriate reduction gears, links, etc. Motor 10 and ribs, respective reducers 11 and 2
For No. 1, it is better to have less backlash, but it is more efficient to have some backlash rather than something so preloaded that the frictional resistance increases. 12 and 22 are the reducer output gears, Mi is the main gear of the final target shaft, 32 and 33 are the bearings,
31 is an arm fixed to the output shaft 30a. Here, backlash necessary for efficient rotation is set between the gear 12 and the addition gear and the gear η and (9). However, the relationship between the gears and the arm 31 is fixed so that there is no play, and the bearing 3
2゜The structure should be such that there is no looseness even when the necessary preload is applied.
Therefore, some friction occurs, but since it only affects 11 axes, it has little effect on the whole. Rotational angle position sensors (encoders, etc.) 13 and Z3 are attached to each motor 10°. The motors 10 and 20 are each fixed to the machine side using a fixing frame 14° or the like. Such a configuration may be configured in various other ways as appropriate within the scope of configuring the following basic form.

First, the two prime movers and their output shafts to the final drive target shaft are each constructed with a mechanism that allows for the backlash necessary for efficient power transmission. However, the final axis is
The shaft and the arms, etc. that perform work through the rotation of the shaft, have a fixed structure that is completely free of play, and the bearing that receives the final output shaft is also appropriately preloaded to ensure that there is no play. Each of the two prime movers is equipped with a rotation angle position sensor.

In the above configuration, the present invention is characterized by controlling and driving as follows.

(1) When the reference positions of the two rotation angle position sensors 13 and B are set to N=O and M=O, respectively, it is assumed that the reducers 11 and 21 have a suitable backlash. Next, when the prime mover 10 is subjected to a minute rotation such that N = + p and M = -pl (in the opposite direction of rotation), the backlash up to the gear 3o is removed by p1.
It is possible to rotate by a minute. Further, when each prime mover is rotated to N=+p+α and M=−p, −α, it can be considered that α is greater than that in which the reduction gears 11 and 21 elastically cause a slight twist.

By shifting the driving positions of the two prime movers in this way, the reducers 11 and 21, which individually have backlash, can be adjusted to any sufficiently small backlash,
Furthermore, it is possible to select a state in which a certain amount of elastic preload is applied. It can be selected regardless of whether the vehicle is stopped or accelerated or decelerated.

(2) It goes without saying that if these two prime movers drive the gear portion of the final target shaft in unison, a large output can be obtained by driving the combined outputs of the two prime movers.

(3) Depending on their relative positions, the dynamic transmission systems of these two prime movers can operate easily with relatively little backlash and no friction, and conversely, under load conditions where the drive systems tend to oscillate. By driving with a phase difference that eliminates backlash, it is possible to drive without transmitting even a large gain.

(4) Issue a rotation command to each of the two prime movers, and send the sensor 13
, n When performing position control driving with feedback applied, if accuracy is required, drive with a phase difference even if there is a certain increase in friction; performs efficient synchronized driving even if there is backlash with the same phase, and after approaching the target, the phase is gradually shifted to eliminate backlash and brake with high accuracy and eliminating oscillation due to overshoot near the target position. You can also select a drive that

(5) Furthermore, the backlash of the drive mechanical system and gear parts will naturally increase over time due to wear of each part, but even in this case, readjusting the backlash will simply increase the phase difference between the two drive commands. This can be solved by simply adjusting.

(6) For even more precise positioning drive, although it is not shown in Figure 5, by attaching a rotational position sensor between the gears, it is easy to perform servo control using the sensor information. In that case, after the carrier stops, the backlash of the drive system is used by calculating from the sensor 13 and the information of the swamp based on the value of the deviation from the target position.
Drive control can be performed in accordance with various conditions to achieve the optimum state, such as re-driving only one side, or re-driving only one side, driving in the direction that increases backlash, reducing friction, and then re-driving afterward to achieve a precise final stop.

(Force) This type of drive produces an effect similar to when the joints of a human arm relax and take a photo in a soft manner, or apply force to make the joints stiff and move without shaking. is.

In the above explanation, we talked about adjusting mainly backlash, but especially in machines with high-speed response and manipulators that are required to produce large outputs with their own lightweight units, the drive system itself is also small and lightweight. , the elastic displacement also increases.

Even in such a case, by applying a large phase difference between the two rows of drive systems to apply a preload to a range that also compensates for elastic displacement, it is possible to solve a situation in which controlled oscillation is difficult to occur. You can also choose.

The present invention relates to a position control drive method, the first feature of which is the use of two drive systems for operation with one degree of freedom, and the second feature of which is to set a positional phase difference between these two drive systems. It is possible.

An embodiment of the present invention is shown in FIG. 1, and 10.20 is a motor;
11 and 21 are speed reducers, 13 and 23 are position sensors, and other symbols are the same as in FIG. 5. Further, reference numeral 15.5 is a drive amplifier that drives the motors 10 and 20, respectively, and operates each motor in response to a position deviation signal 81 (1,320) from the control section 40.
Now, input the position command Sll for the corresponding driven body such as the arm 31, perform deviation processing with the position detection signal S1 of the position sensor 13, and send the deviation signal S to the drive amplifier 15.
10, and at the same time performs deviation processing between the value 821 obtained by subtracting the phase difference command φ from the position command 811 and the output S2 of the position sensor n, and outputs 820 to the drive amplifier 5. Through the above control, the motor 10 is controlled to the position command 311, and the motor (9) is controlled to a position having a phase difference of φ from the position command S21, that is, 811.

Next, the effect of controlling the motors 10 and 20 with a phase difference of φ will be explained. FIG. 2 schematically shows the backlash of a reduction gear, etc., and assumes that the amount of backlash between the main gear (9) and the motors 10 and 20 is θ.

Now, when φ=0 in FIG. 1, the motor 10 and the motor have no phase difference and are controlled by the same position command. At this time, a certain backlash exists between the main gear and the motors 10 and 20, and the position command and the position of the main gear I may not match. Furthermore, in order to eliminate this positional deviation, consideration must be given to the outside, such as applying preload with a spring or the like to control the position. However, since the motors 10 and 20 operate in a uniform manner, they operate smoothly.

Next, when φ=θ, the position of the motor 10 and the motor nodule is controlled with a phase difference corresponding to backlash, so
Ideally, there would be no backlash, and the position command and main gear would match. Therefore, there is no need to take any consideration such as compensating for positional deviation as in the case of φ=O. Further, since the motor 10 and the motor force operate while maintaining a phase difference of φ=θ, they do not interfere with each other, and therefore operate relatively easily.

Furthermore, when φ>θ, the phase difference between the motor 10 and the motor force is controlled to a value larger than the backlash.
Since the main tooth loading shown in FIG. 2 is operated while the motor 10 and the silver are engaged with each other in opposite directions, there is no backlash, but the operation becomes heavy. Also,
The position of the main gear (9) when stopped does not match the position command,
Motor 10. ! It is expected that there will be a certain position where the torque is matched with that of :20. However, by a method such as setting φ=θ after the -carrying is stopped, it is possible to perform control to eliminate positional deviation without any external consideration.

'Also, in the range of O x φ x θ, backlash exists, and the position command and the main gear do not match because φ =
It is the same as at time 00, but since the motors 10 and 20 do not necessarily perform the speech operation, the ease of operation is about the same as when φ=θ.

If the above explanation is put into a table, it will be summarized as follows.

According to this, if the position control drive method of the present invention is realized with a phase difference of φ = θ, there will be no backlash, no position deviation with respect to the position command, and in addition, the position control drive of the final target axis can be performed with relatively light operation. It turns out that it is possible.

FIG. 3 shows another embodiment of the present invention. In the embodiment described above, a position control drive method was shown in which the phase difference φ between the two drive systems was set to a constant value, but in this embodiment, the position It is characterized in that the phase difference φ is changed in a predetermined pattern depending on the value of the deviation 810 between the command 811 and the position sensor output S1.

Most of them are the same as those in FIG. 1, but the difference is that the phase difference φ is not set externally, but is determined by the phase difference determining section 41 based on the value of S10. The phase difference determining section 41 determines φ using a pattern as shown in FIG. 4, for example. The gist of FIG. 4 is that, first, when the difference 810 between the position command S11 and the position of the main gear 13 is large, φ=0 and the motors 10, 2
0 is controlled and driven lightly, and secondly, 810
This is the point at which control is performed with no backlash and no position command and no position deviation by setting φ=θ until the position approaches 0 and stops. By performing control in this way, it is possible to drive the final target axis lightly and at high speed when making a large movement, and to ensure positional accuracy when stopping or operating at low speed.For example, it is possible to drive the joints of a manipulator. It is highly effective when applied to

10 Effects of the invention (a) Jltj: The power transmission system from the motive force to the final drive shaft may have backlash under normal conditions.
The most suitable one can be selected from among various reduction gears and link mechanisms. According to the present invention, the backlash can be set to any value that suits the driving situation! I4! I can do it.

(b) Because joints can be controlled to be in a relaxed state or in a tight state, like the joints of a human arm, oscillations are less likely to occur during detailed work, and if oscillations occur, the relaxed state at that time is It is possible to control the stability by making changes.

(c) It may seem wasteful to have two drive systems, but in manipulators, which are used in fields that require reliability, if one fails, the output will be halved, but the remaining drive system will be able to survive the emergency, so it is reliable. It is possible to improve sexual performance.

[Brief explanation of drawings]

2 is a schematic diagram of backlash, FIG. 3 is a block diagram of a position drive control method according to another embodiment of the present invention, and FIG. 4 is an example of a pattern of a phase difference determining section. FIG. 5 is a perspective view of a drive system showing an example of application of the present invention. 10.20-4-1.11, 21-...Reduction gear, 13
, , D-...Position sensor, 12.22...Reducer output gear, 15, 25...Drive amplifier, Machining...Main gear, 31...Arm, 40...Control unit, 41 ...Phase difference determining section. Fig. 1 Precedent of the present invention 10.20---Motor 11.21---Ichisada Tatsushiki 12.22---One engine number 13.23---4tLiffic unit 15.25---
-1 station fh? Figure I-1 - L output 40----- System # Section Figure 4 A1 Pattern for changing the barley method I1 Figure 5

Claims (2)

[Claims] (1) A first device that performs deviation processing on a first position detection signal and a position command signal corresponding to a driven object to obtain a first deviation signal, and controls a first drive source using the first deviation signal. a drive system, and calculates the position command signal and the position command signal to obtain a calculation signal, performs deviation processing on the calculation signal and a second position detection signal, and controls a second drive source using the second deviation. Second to do
A position control drive method characterized in that a driven system with one degree of freedom is driven by a drive system. (2) A first device that performs deviation processing on the first position detection signal and a position command signal corresponding to the driven object to obtain a first deviation signal, and controls the first drive source using the first deviation signal. a drive system, a phase difference command signal is obtained by the first deviation signal, a second deviation signal is obtained by arithmetic processing of the phase difference command signal and the position command signal, and a second deviation signal is obtained by the second deviation signal. A position control drive method characterized in that a driven system having one degree of freedom is driven by a second drive system that controls a second drive source.