JPS59103593A - Motor drive device for robot - Google Patents

Abstract

PURPOSE:To enable to produce the output of a motor in more than the continuously using rated condition by calculating the motor temperature by the motor temperature rise value and the environmental temperature calculated from the current value of the motor, the quantity of generated heat and heat sink characteristic, and controlling the motor current by the calculated motor temperature. CONSTITUTION:A motor temperature rise calculator 2 obtains the temperature rise value of a motor from the current value of the motor detected by a current detector 1 on the basis of the quantity of generated heat and the heat sink characteristic of the motor. A motor temperature calculator 4 calculates the temperature of the motor from the environmental temperature measured by a temperature sensor 3 and the output of the temperature rise calculator 2. A motor current controller 5 obtains the maximum allowable motor current for the motor temperature by the specifications of the motor and the calculated motor temperature and drives the motor 6 with the maximum allowable motor current.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a motor for various robots such as manipulators, and is adapted to be used in a super-duty manner so that the output of the motor can be as large as possible.

In robots, for example, articulated manipulators with built-in motors, there is a close relationship between the load they can handle and the output of the motor, and if you want to handle a large load, you will need a motor with a high output. Therefore, the external size of the motor becomes large, and the manipulator also becomes large. Due to its intended use, manipulators are required to be as small as possible and capable of handling large loads;
It is necessary to increase the power as much as possible without increasing the external size.

It is difficult to meet such requirements, as it is assumed that the motor is used within the normal 9-toy usage rating.

However, the motor has a certain capacity, and as shown in FIG. 1, it is possible to draw out an output that exceeds the continuous use rating, even though it is only rated 8. Therefore, as long as this condition is adhered to,
Even a small motor can produce large output.

However, when a motor is used above its continuous use rating, the problem is that even if the voltage, current, and load are kept within the maximum ratings, the temperature rises due to the load current, that is, the motor current. In other words, if the temperature of the motor is low, it can be used for a short period of time against an overload of the rated current for continuous use.
If the temperature rises and the temperature rises, it will disappear when used.

It is a good thing to measure the temperature of the motor and control the load handled according to the temperature, but installing a temperature sensor such as 5 pairs of thermal sensors on each motor means that robots often have to cut the motor. This increases the number of orientation machines, which is not desirable from the rL point of downsizing.

The present invention is based on the above-mentioned considerations, and each motor has a C
The purpose of the present invention is to provide a motor movement device for a robot that measures the temperature of a motor without accessing a temperature sensor such as a convex couple, and performs short-term overload pressing in accordance with the measured temperature.

The main feature of the robot motor system of the present invention that achieves this purpose is to use a current detector to detect the motor current of the robot, the detected motor 'L'J, the amount of heat generated, the heat dissipation characteristics, and the furnace. Calculate the motor temperature from the motor temperature rise calculation coloring, the temperature sensor that measures the ambient temperature, and the calculated morph temperature rise value. A motor temperature device and a motor current control device that controls the motor current based on the calculated motor temperature? : What I prepared fl : % mark. The present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing the principle of the present invention, in which a current detector 1 detects the robot's motor current, and this motor current value is input to a motor temperature rise calculation device 2. The motor current can be measured continuously at 6(!) constants, or at constant intervals to calculate the average current value every few seconds to several minutes.The temperature rise of the motor depends on the characteristics of heat generation and heat radiation. The amount of heat generated depends on the motor current, so before the motor temperature rises!
@Instrument 2 calculates the temperature rise value of the motor from the input motor current value by fl, J'g, based on the heat generation amount and heat radiation characteristics of the motor to be driven.

However, it is natural that the amount of heat generated and the characteristics of heat radiation differ depending on the motor, and also vary depending on the mounting method and heat radiation method of the motor, so the characteristics due to these differences should be determined in advance. Go down the correction.

Since the temperature of the motor is determined by the ambient temperature and the temperature value of the motor, the temperature sensor 3 is installed near the robot to adjust the temperature of thermocouples, temperature resistors, etc. Output and Nil Motor temperature rise calculation device 2 output 7:
j) etc., set the motor's dA degree to 4 using the morph temperature calculation device 4.
T river. In addition, the temperature sensor 3 is
Since there is no need to set the motor separately, there is no need to worry about attaching it to each motor separately, or if the robot is +A'J-3, attaching it separately to the valley robot.
The point is that 5'i''L is good for measuring the ambient temperature of the robot.However, the installation of this temperature sensor 3 does not make the power distribution complicated or make the robot larger.

The morph current controller 5 determines the maximum allowable motor current for the motor temperature from the motor temperature determined by calculation and the specifications of the motor, and drives the motor 6 with this maximum tf motor current. To give an example of the motor current control section of a torque motor used in a manipulator,
Torque-rotational speed/current characteristics of ml Bi1 published by 71) et al.)
It is possible to use the motor in the operating range 1 for a short period of time by controlling the operating conditions so that the motor current is 2 to 3 times the rated current for continuous use. As the motor temperature increases, the continuous use rated current 2 is lowered by one step to suppress the motor current. In addition, if the motor temperature exceeds the π rating due to excessive waves, the motor current will be reversed due to the load. Continuous use within the range of 11M or more than the rated current 7"\
The motor current is limited to mlJ at a small value, for example about 3A, to cool the motor quickly.

The above-mentioned motor drive device 6. According to this method, a smaller motor can be used for the same load than before.

With this, it is possible to make robots such as manifold rake smaller and more powerful. In addition, since the motor temperature increases by 1 s due to the motor current, it is also possible to
1=The present invention can be applied without modification. Conveniently, since the motor γ resistance can be measured, it is possible to monitor the motor for abnormal use. A specific example of encounter will be explained.

In Figure 3, 61 to 64 are Meimon J motors, and 7I to 74 are 1 each! 8□~84 are the servo control devices for each motor, 9 is the control panel for the manibrae 4, 1
0 is multiplexer (8 tp), it is % change% fr
a% 12 is microflosser (CPIJ), 1
3 is a memory, 14 is an L)/A converter, 15 is 1 filter, 1 (i is a sequencer, and the calculation of the motor nA k and the maximum allowable motor current are performed by digital processing. The servo control devices □ to 84 are omitted.

In FIG. 3, the motor currents of motors 1 to 64 of each joint are taken out by the respective current detectors 1, and the current signals of each motor and the output signal of the temperature sensor 3 are sequentially sent to the multiplexer 10. Converter IJ.

The current 1ffiα and the four ambient temperatures are converted into fully digital signals. The memory 13 includes reading of current value data,
Find motor temperature rise and motor temperature? Programs for controlling the motor current based on the calculation results and the calculation results are stored in the storage area 9, the reeds, and the 7′ do′tons 11. Value data record 11) 2 Ambient temperature data record/range, light r? Memory of supplementary data for 4 and O/heat dissipation 9te characteristics, a2 L':f, + II 4γA old memory of each motor specification, and temporary rewrite 1/C for u/L calculation also used. It's J'L.

The microflow processor 12 is a digitalized motor '1
[(Flow value 9 Calorific value - With heat radiation Note) Using extraction pressure data of The temperature of each motor is determined using .Next, the maximum motor current iM at the humidity of each motor is determined.

Microflosser 12 has maximum Wf name - motor 5 flow 1
Since it is output as a direct impulse digital signal, it is converted to an analog signal (low voltage) by the IJ/eight converter 14, and this analog signal is sent to the servo warning device of the corresponding motor.

At each ZARHO 1ltiJ elevation 1'; t8t-84, each Morph 1-G4 is dispatched without restricting the morph electric circuit 1□ money to the 1h flow 1 indicated by the analog E.

Although the I10 baud) 15 and the sequencer 16 are not essential to the present invention, the i10 baud 15 is a switch. When sending a signal to the outside from the microprocessor 12 so that the microprocessor 12 can read the shape of the relay contact, etc. It is a control panel with internal parts, etc., and it switches between automatic operation and manual operation, operates and stops the servo thread from the microflosser 12 and No. 5 VC, and controls the motor 11 flow. As explained above, according to the present invention, it is possible to extract the output of the motor beyond the continuous use rating, and it has a great effect on downsizing and output of various robots including manipulators.

[Brief explanation of drawings]

Fig. 1 is a torque-(b) rotation speed/11 flow characteristic diagram of a torque motor, Fig. 2 is a front diagram showing the principle of the present invention, and Fig. 3 is a diagram showing the present invention as an internal pulling motor 11/IK jV! Type 1 Takanj
``I1'' is a fluorocarbon rough 4 which shows a specific example of a maniflator. 5 is a motor current monitoring device, 6.6 to 6 are motors, 81 to 84 are servo control devices f:i), 10 is a multiplexer, and 11 is an A/D converter. , 12 is a microprocessor, 13 is a memory, 14 is a 1)/A converter, and 1G is a sequencer.

Claims (1)

[Claims] A current extractor that extracts the motor current of the robot, and Ep,
A motor temperature rise @ calculation device that calculates the temperature rise of the motor from the output motor current value, heat generation amount, and heat radiation characteristics, and also the ambient temperature A motor temperature calculation device that calculates the motor temperature from the ambient temperature obtained, and a motor flow control device that controls the motor current based on the obtained motor temperature.
Motor drive equipment for robots.