Patent Application
20190152072
The present invention relates to a robot.
Researches and developments of a control device that controls a robot have been conducted.
In relation to the researches and developments, there is known a robot controlled by an externally attached control device (see JP-A-2011-177845 (Patent Literature 1)).
When the robot is controlled by the externally attached control device, in some case, a setting area (a footprint) for disposing the robot and the control device is large and a setting place is limited. When a robot is controlled by a control device incorporated in the robot, the setting area is small. However, in this case, a deficiency sometimes occurs in a part of the robot and the control device because of heat emitted from a heat source part among parts of the control device on the inside of the robot.
An aspect of the invention is directed to a robot including: a driving section; and a power supply section configured to supply electric power to the driving section. The power supply section includes a first power supply circuit and a second power supply circuit and is located on an inside of the robot.
With this configuration, the robot can prevent an increase in a setting area and prevent a temperature rise of the power supply section.
In another aspect of the invention, the robot may be configured such that a first input circuit and a first output circuit included in the first power supply circuit are electrically isolated, a second input circuit and a second output circuit included in the second power supply circuit are electrically isolated, an output terminal on a high-potential side of output terminals of the first output circuit and an output terminal on a low-potential side of output terminals of the second output circuit are connected, and the power supply section applies, between an output terminal on a low-potential side of the output terminals of the first output circuit and an output terminal on a high-potential side of the output terminals of the second output circuit, a voltage obtained by adding up an output voltage of the first output circuit and an output voltage of the second output circuit.
With this configuration, the robot can supply desired electric power to the driving section while preventing a temperature rise of the power supply section.
In another aspect of the invention, the robot may be configured such that a rated output power value of the first power supply circuit is equal to a rated output power value of the second power supply circuit.
With this configuration, the robot can supply electric power to the driving section with the first power supply circuit and the second power supply circuit while preventing a deficiency from occurring in at least one of the first power supply circuit and the second power supply circuit because of a difference between the rated output power values of the first power supply circuit and the second power supply circuit.
In another aspect of the invention, the robot may be configured such that an output voltage of the first power supply circuit is equal to an output voltage of the second power supply circuit.
With this configuration, the robot can supply electric power to the driving section with the first power supply circuit and the second power supply circuit while preventing a deficiency from occurring in at least one of the first power supply circuit and the second power supply circuit because of a difference between the output voltages of the first power supply circuit and the second power supply circuit.
In another aspect of the invention, the robot may be configured such that at least one of the first input circuit and the second input circuit includes a harmonic current suppression circuit.
With this configuration, the robot can suppress noise that occurs in at least one of the first power supply circuit and the second power supply circuit.
In another aspect of the invention, the robot may be configured such that the robot further includes a power converting section configured to convert electric power supplied from the power supply section into electric power supplied to the driving section.
With this configuration, the robot can drive the driving section with electric power supplied by both of the first power supply circuit and the second power supply circuit and converted by the power converting section.
In another aspect of the invention, the robot may be configured such that the power supply section is capable of supplying, in a predetermined time, electric power having a power value not less than 1.1 times and not more than four times of a rated output power value.
With this configuration, the robot can supply, to the driving section, electric power necessary for starting to turn the driving section in the robot.
The invention will be described with reference to the accompanying drawings, wherein like numbers reference like elements.
An embodiment of the invention is explained below with reference to the drawings.
First, the configuration of a robot 1 is explained.
The robot 1 includes a base B set on a setting surface and a movable section A supported by the base B. The setting surface refers to a surface on which the robot 1 is set such as a floor surface of a room in which the robot 1 is set, a wall surface of the room, a ceiling surface of the room, the outdoor ground, an upper surface of a table, or an upper surface of a stand.
The base B is configured from two parts. One of the parts is a first base B1 and the other is a second base B2. A space on the inner side of the first base B1 is connected to a space on the inner side of the second base B2.
The first base B1 is set on the setting surface. The first base B1 has a substantially rectangular parallelepiped (or cubic) shape as an external shape. The first base B1 is configured from tabular surfaces and is hollow. The second base B2 is fixed to a first upper surface, which is a part of the upper surface of the first base B1. The upper surface is a surface on the opposite side of the setting surface among the surfaces of the first base B1. The distance between a second upper surface, which is a portion other than the first upper surface of the upper surface of the first base B1, and the setting surface is short compared with the distance between the first upper surface and the setting surface. Therefore, a gap is present between the second upper surface and the second base B2. The movable section A is provided on the second upper surface. That is, the first base B1 supports the movable section A. The shape of the first base B1 may be another shape instead of such a shape if the other shape is a shape that enables the second base B2 to be fixed to a part of the upper surface of the first base B1.
The second base B2 has, as an external shape, a shape obtained by cutting off, in a direction perpendicular to two surfaces opposed to each other configuring a rectangular parallelepiped (or a cube), a triangular portion including one vertex in each of the two surfaces to be removed. The shape obtained by cutting off the portion may be not always formed by machining for cutting off the portion and may be formed by, for example, machining for forming the same shape from the beginning. The second base B2 has such a polyhedron shape as the external shape. The second base B2 is configured from tabular surfaces and is hollow. The shape of the second base B2 may be another shape instead of such a shape if the other shape is a shape that enables the second base B2 to be fixed to a part of the upper surface of the first base B1.
The movable section A includes a first arm A1 supported turnably around a first turning axis AX1 by the base B, a second arm A2 supported turnably around a second turning axis AX2 by the first arm A1, and a shaft S supported turnably around a third turning axis AX3 and translatably in the axial direction of the third turning axis AX3 by the second arm A2.
The shaft S is a columnar shaft body. A not-shown ball screw groove and a not-shown spline groove are respectively formed on the circumferential surface of the shaft S. In this example, the shaft S is provided to pierce through an end portion on the opposite side of the first arm A1 of end portions of the second arm A2 in a first direction, which is a direction in which the base B is set on the setting surface and is a direction perpendicular to the setting surface. The first direction is, for example, a direction along a Z axis in a robot coordinate system RC shown in
In this example, the first arm A1 turns around the first turning axis AX1 and moves in a second direction. The second direction is a direction orthogonal to the first direction. The second direction is, for example, a direction along an XY plane, which is a plane formed by an X axis and a Y axis in the robot coordinate system RC. The second direction may be a direction not along the XY plane instead of the direction along the XY plane.
The first arm A1 is turned (driven) around the first turning axis AX1 by a driving section M1 included in the base B. That is, in this example, the first turning axis AX1 is an axis coinciding with a driving axis of the driving section M1. The first turning axis AX1 and the driving axis of the driving section M1 may not coincide with each other. In this case, for example, the driving section M1 turns the first arm A1 around the first turning axis AX1 with, for example, a method of turning the first arm A1 using a pulley and a belt.
In this example, the second arm A2 turns around the second turning axis AX2 and moves in the second direction. The second arm A2 is turned around the second turning axis AX2 by a driving section M2 included in the second arm A2. That is, in this example, the second turning axis AX2 is an axis coinciding with a driving axis of the driving section M2. The second turning axis AX2 and the driving axis of the driving section M2 may not coincide with each other. In this case, for example, the driving section M2 turns the second arm A2 around the second turning axis AX2 with, for example, a method of turning the second arm A2 using a pulley and a belt.
The second arm A2 includes a driving section M3 and a driving section M4 and supports the shaft S. The driving section M3 moves (lifts and lowers) the shaft S in the first direction by turning, with a timing belt or the like, a ball screw nut provided in the outer circumferential portion of the ball screw groove of the shaft S. The driving section M4 turns the shaft S around the third turning axis AX3 by turning, with a timing belt or the like, a ball spline nut provided in the outer circumferential portion of the spline groove of the shaft S.
In the following explanation, as an example, all of the driving sections M1 to M4 have the same configuration. In the following explanation, the driving sections M1 to M4 are collectively referred to as driving section M unless it is necessary to distinguish each of the driving sections M1 to M4. A part or all of the driving sections M1 to M4 may have configurations different from one another.
The driving section M is, for example, a servomotor. The driving section M may be another actuator driven by electricity. In this example, the driving section M is a servomotor configured integrally with each of an amplifier section including a driving circuit configured to drive a motor and an encoder configured to detect information indicating a turning angle of the driving section M. When driving the driving section M, the driving circuit performs switching control. The switching control is, for example, PWM (Pulse Width Modulation) control. The switching control may be other switching control instead of the PWM control. The driving section M may be configured separately from one or both of the amplifier section and the encoder.
The robot 1 is controlled by the control device 30. The robot 1 incorporates the control device 30 therein. The robot 1 may be controlled by the control device 30 externally attached to the robot 1.
The control device 30 is a controller configured to control the robot 1. The control device 30 controls each of the four driving sections M (i.e., the driving sections M1 to M4) and operates the robot 1. The control device 30 includes a power supply section EP and a power converting section IV for each of the four driving sections M.
In this example, portions other than each of the power supply section EP and the power converting section IV among portions of the control device 30 are located on the inner side of the first base B1 on the inside of the robot 1. In this example, the power supply section EP of the control device 30 is located on the inner side of the second base B2. The power converting section IV of the control device 30 may be provided in any position on the inside of the robot 1. The power converting section IV may be included in the driving section M, to which the power converting section IV supplies electric power, or may be included in another member included in the robot 1 instead of being included in the control device 30. In the example shown in
The power supply section EP and the power converting section IV are explained with reference to
The power supply section EP is provided on the inner side of the second base B2, that is, on the inside of the robot 1. Therefore, the power supply section EP is located on the inside. The power supply section EP supplies electric power to the driving section M. More specifically, the power supply section EP supplies electric power to the power converting section IV. The power converting section IV converts the electric power supplied from the power supply section EP into electric power supplied to the driving section M and supplies the converted electric power to the driving section M. That is, the power supply section EP supplies the electric power to the driving section M via the power converting section IV.
As shown in
The power supply section EP includes a first power supply circuit EP1 and a second power supply circuit EP2. More specifically, the power supply section EP includes two separate substrates, that is, a first substrate BP1 and a second substrate BP2 (see
The first power supply circuit EP1 includes a first input circuit CI1, an isolation transformer TR1, and a first output circuit CO1 electrically isolated from the first input circuit CI1 by the isolation transformer TR1. In this example, in the first power supply circuit EP1, the first input circuit CI1 and the first output circuit CO1 are electrically isolated by the isolation transformer TR1. However, the first input circuit CI1 and the first output circuit CO1 may be electrically isolated by another element instead of the isolation transformer TR1.
The first input circuit CI1 is a circuit on a primary side in the first power supply circuit EP1. The first input circuit CI1 includes a not-shown rectifier and a not-shown smoothing circuit and supplies the AC power supplied from the AC power supply EP0 to the isolation transformer TR1. The first input circuit CI1 may be any circuit if the circuit is capable of supplying the AC power to the isolation transformer TR1. In the example shown in
As explained above, the isolation transformer TR1 electrically isolates the first input circuit CI1 and the first output circuit C01. When the AC power is supplied from the first input circuit CI1, the isolation transformer TR1 outputs the AC power to the first output circuit C01.
The first output circuit CO1 is a circuit on a secondary side in the first power supply circuit EP1. The first output circuit CO1 includes a not-shown rectifier and a not-shown smoothing circuit and converts the AC power supplied from the isolation transformer TR1 into DC power. The first output circuit CO1 includes two output terminals, that is, an output terminal CP1 and an output terminal CN1. The output terminal CP1 is an output terminal on a high-potential side in the first output circuit C01. The output terminal CN1 is an output terminal on a low-potential side in the first output circuit C01.
When the AC power is supplied from the isolation transformer TR1, the first output circuit CO1 converts the supplied AC power into DC power and causes a potential difference corresponding to the converted DC power between the output terminal CP1 and the output terminal CN1. At this time, potential applied to the output terminal CP1 is higher than potential applied to the output terminal CN1. As explained above, the first output circuit CO1 is electrically isolated from the first input circuit CI1 by the isolation transformer TR1. Therefore, the first output circuit CO1 can be regarded as a battery including the output terminal CP1 as a plus terminal and including the output terminal CN1 as a minus terminal. That is, when the first output circuit CO1 is regarded as the battery, the first input circuit CI1 is equivalent to an electromotive force of the first output circuit C01, which is the battery. The first output circuit CO1 may be any circuit if the circuit is capable of causing a potential difference corresponding to the DC power supplied from the isolation transformer TR1 between the output terminal CP1 and the output terminal CN1.
The second power supply circuit EP2 includes a second input circuit CI2, an isolation transformer TR2, and a second output circuit CO2 electrically insulted from the second input circuit CI2 by the isolation transformer TR2. In this example, in the second power supply circuit EP2, the second input circuit CI2 and the second output circuit CO2 are electrically isolated by the isolation transformer TR1. Therefore, the second input circuit CI2 and the second output circuit CO2 may be electrically isolated by another element instead of the isolation transformer TR2.
The second input circuit CI2 is a circuit on a primary side in the second power supply circuit EP2. The second input circuit CI2 includes a not-shown rectifier and a not-shown smoothing circuit and supplies the AC power supplied from the AC power supply EP0 to the isolation transformer TR2. The second input circuit CI2 may be any circuit if the circuit is capable of supplying the AC power to the isolation transformer TR2. In the example shown in
As explained above, the isolation transformer TR2 electrically isolates the second input circuit CI2 and the second output circuit CO2. When the AC power is supplied from the second input circuit CI2, the isolation transformer TR2 outputs the AC power to the second output circuit CO2.
The second output circuit CO2 is a circuit on a secondary side in the second power supply circuit EP2. The second output circuit CO2 includes a not-shown rectifier and a not-shown smoothing circuit and converts the AC power supplied from the isolation transformer TR2 into DC power. The second output circuit CO2 includes two output terminals, that is, an output terminal CP2 and an output terminal CN2. The output terminal CP2 is an output terminal on a high-potential side in the second output circuit CO2. The output terminal CN2 is an output terminal on a low-potential side in the second output circuit CO2.
When the AC power is supplied from the isolation transformer TR2, the second output circuit CO2 converts the supplied AC power into DC power and causes a potential difference corresponding to the converted DC power between the output terminal CP2 and the output terminal CN2. At this point, potential applied to the output terminal CP2 is higher than potential applied to the output terminal CN2. As explained above, the second output circuit CO2 is electrically isolated from the second input circuit CI2 by the isolation transformer TR2. Therefore, the second output circuit CO2 can be regarded as a battery including the output terminal CP2 as a plus terminal and including the output terminal CN2 as a minus terminal. That is, when the second output circuit CO2 is regarded as the battery, the second input circuit CI2 is equivalent to an electromotive force of the second output circuit CO2, which is the battery. The second output circuit CO2 may be any circuit if the circuit is capable of causing a potential difference corresponding to the DC power supplied from the isolation transformer TR2 between the output terminal CP2 and the output terminal CN2.
The first power supply circuit EP1 and the second power supply circuit EP2 may have the same configuration or may have configurations different from each other. In the following explanation, as an example, the first power supply circuit EP1 and the second power supply circuit EP2 have the same configuration.
In the example shown in
Since the output terminal CP1 and the output terminal CN2 are connected in this way, the power supply section EP can apply, between the output terminal CN1 and the output terminal CP2, a voltage obtained by adding up the output voltage of the first power supply circuit EP1 and the output voltage of the second power supply circuit EP2. In other words, in the power supply section EP, a load factor of the power supply section EP is dispersed to each of the first power supply circuit EP1 and the second power supply circuit EP2 compared with when the same voltage as the voltage is supplied to the driving section M by one power supply circuit. Therefore, the power supply section EP can prevent a temperature rise of the power supply section EP compared with when the same voltage as the voltage is supplied to the driving section M by one power supply circuit. The temperature rise of the power supply section EP is further prevented as the first power supply circuit EP1 and the second power supply circuit EP2 are further separated because heat generated by the first power supply circuit EP1 and heat generated by the second power supply circuit EP2 are dispersed. That is, the control device 30 can supply desired electric power to the driving section M while preventing the temperature rise of the power supply section EP. In this example, a load factor of the power supply section EP at certain timing means a ratio of a power value of electric power supplied by the power supply section EP at the timing to the rated output power value of the power supply section EP.
The output terminal CP2 is connected to an input terminal on a high-potential side of input terminals of the power converting section IV. The output terminal CN1 is connected to an input terminal on a low-potential side of the input terminals of the power converting section IV. Consequently, the power supply section EP supplies DC power to the power converting section IV with the first output circuit CO1 and the second output circuit CO2 connected in series. That is, the power supply section EP supplies the DC power to the driving section M via the power converting section IV with the first output circuit CO1 and the second output circuit CO2 connected in series.
The power supply section EP is capable of supplying, in a predetermined time, electric power having a power value not less than first predetermined number times and not more than second predetermined number times of the rated output power value. The first predetermined number is, for example, 1.1. The first predetermined number may be any number if the number is smaller than the second predetermined number and larger than 1. More desirably, the first predetermined number is 1.5. Consequently, the robot 1 is capable of further educing performance of the driving section M during acceleration of the movable section A compared with when the first predetermined number is 1.1. The second predetermined number is, for example, four. The second predetermined number may be any number if the number is larger than the first predetermined number.
More specifically, the first power supply circuit EP1 is configured to be capable of supplying, in the predetermined time, electric power having a power value not less than first predetermined number times and not more than second predetermined number times of the rated output power value of the first power supply circuit EP1. The second power supply circuit EP2 is configured to be capable of supplying, in the predetermined time, electric power having a power value not less than first predetermined number times and not more than second predetermined number times of the rated output power value of the second power supply circuit EP2. In this example, the predetermined time is a certain short time in a period in which the robot 1 is operating. The predetermined time is, for example, approximately 0.5 seconds. The predetermined time may be a time shorter than 0.5 second or may be a time longer than 0.5 seconds. Consequently, the control device 30 can supply electric power necessary in starting to turn the driving section M in the robot 1 to the driving section M.
When DC power is supplied from the power supply section EP via the two input terminals of the power converting section IV, the power converting section IV converts the DC power supplied from the power supply section EP into electric power supplied to the driving section M. When the driving section M is driven by DC power, the electric power is the DC power. When the driving section M is driven by AC power, the electric power is the AC power. The power converting section IV supplies the converted electric power to the driving section M. The power converting section IV supplies the electric power to the driving section M according to switching control. The switching control is, for example, PWM control. The switching control may be other switching control instead of the PWM control. The power converting section IV is, for example, an inverter circuit. The power converting section IV may be, instead of the inverter circuit, another circuit capable of converting the DC power supplied from the power supply section EP into the electric power.
Advantages of the power supply by the power supply section EP in the control device 30 are explained while comparing a power supply section EPX (e.g., a power supply section in the past) different from the power supply section EP and the power supply section EP.
The power supply section EPX is a power supply section capable of supplying electric power to the driving section M with one power supply circuit. In the following explanation, as an example, the power supply section EPX includes, as the one power supply circuit, a third power supply circuit EP3, which is a power supply circuit having the same configuration as the first power supply circuit EP1.
An allowable load factor of the power supply section EPX decreases according to a temperature rise around the power supply section EPX. Therefore, the power supply section EPX is used while being cooled by one cooling method of natural air cooling for performing cooling with a naturally flowing air flow (an non-artificial air flow) and forced air cooling for performing cooling with an artificial air flow caused by a fan or the like. In this example, an allowable load factor of the power supply section EPX at certain timing means a ratio of a power value of electric power that the power supply section EPX can supply without causing a deficiency at the timing to the rated output power value of the power supply section EPX. The temperature around the power supply section EPX means the temperature of an air flow before touching the power supply section EPX to have higher temperature (i.e., an air flow cooled above the power supply section EPX) in an air flow circulating in a space in which the power supply section EPX is set.
It is seen by comparing
As opposed to such a power supply section EPX, the power supply section EP can prevent a time in which the robot 1 can be continuously operated without a rest from decreasing while reducing the manufacturing cost of the control device 30 by adopting the natural air cooling as the cooling method for the power supply section EP. As explained above, when causing the power supply section EP to perform power supply at a load factor of V[%], the load factor of the power supply section EP is dispersed to a load factor of the first power supply circuit EP1 and a load factor of the second power supply circuit EP2. In this case, the load factor of the first power supply circuit EP1 and the load factor of the second power supply circuit EP2 are respectively (V/2) [%]. In this example, as explained above, the power supply section EPX is the power supply section including the third power supply circuit EP3. That is,
For example, when causing the power supply section EP to perform power supply at a load factor of 60[%], the load factor of the first power supply circuit EP1 and the load factor of the second power supply circuit EP2 are respectively 30[%]. In this case, when the natural air cooling is adopted as the cooling method for the first power supply circuit EP1, as shown in
Portions other than the power supply section EP and the power converting section IV in the control device explained above may be located in positions (e.g., positions on the inner side of the second base B2) other than positions on the inner side of the first base B1 among positions on the inside of the robot 1. In this example, the power supply section EP explained above may be located in a position (e.g., a position on the inner side of the first base B1) other than a position on the inner side of the second base B2 among the positions on the inside of the robot 1.
In
As explained above, the robot 1 includes the driving section (in this example, the driving section M) and the power supply section (in this example, the power supply section EP) configured to supply electric power to the driving section. The power supply section includes the first power supply circuit (in this example, the first power supply circuit EP1) and the second power supply circuit (in this example, the second power supply circuit EP2). The power supply section is located on the inside of the robot (in this example, the inner side of the second base B2). Consequently, the robot 1 can prevent an increase in a setting area and prevent a temperature rise of the power supply section.
In the robot 1, the first input circuit (in this example, the first input circuit CI1) and the first output circuit (in this example, the first output circuit CO1) included in the first power supply circuit are electrically isolated. The second input circuit (in this example, the second input circuit CI2) and the second output circuit (in this example, the second output circuit CO2) included in the second power supply circuit are electrically isolated. The output terminal on the high-potential side (in this example, the output terminal CP1) of the output terminals of the first output circuit and the output terminal on the low-potential side (in this example, the output terminal CN2) of the output terminals of the second output circuit are connected. The power supply section applies, between the output terminal on the low-potential side (in this example, the output terminal CN1) of the output terminals of the first output circuit and the output terminal on the high-potential side (in this example, the output terminal CP2) of the output terminals of the second output circuit, a voltage obtained by adding up an output voltage of the first output circuit and an output voltage of the second output circuit. Consequently, the robot 1 can supply desired electric power to the driving section while preventing a temperature rise of the power supply section.
In the robot 1, the rated output power value of the first power supply circuit is equal to the rated output power value of the second power supply circuit. Consequently, the robot 1 can supply electric power to the driving section with the first power supply circuit and the second power supply circuit while preventing a deficiency from occurring in at least one of the first power supply circuit and the second power supply circuit because of a difference between the rated output power values of the first power supply circuit and the second power supply circuit.
In the robot 1, the output voltage of the first power supply circuit is equal to the output voltage of the second power supply circuit. Consequently, the robot 1 can supply electric power to the driving section with the first power supply circuit and the second power supply circuit while preventing a deficiency from occurring in at least one of the first power supply circuit and the second power supply circuit because of a difference between the output voltages of the first power supply circuit and the second power supply circuit.
In the robot 1, at least one of the first input circuit and the second input circuit includes the harmonic current suppression circuit (in this example, the harmonic current suppression circuit HS1 or the harmonic current suppression circuit HS2). Consequently, the robot 1 can suppress noise that occurs in at least one of the first power supply circuit and the second power supply circuit.
The robot 1 includes the power converting section (in this example, the power converting section IV) configured to convert electric power supplied from the power supply section into electric power supplied to the driving section. Consequently, the robot 1 can drive the driving section with electric power supplied by both of the first power supply circuit and the second power supply circuit and converted by the power converting section.
In the robot 1, the power supply section is capable of supplying electric power having a power value not less than 1.1 times and not more than four times of the rated output power value. Consequently, the robot 1 can supply, to the driving section, electric power necessary when starting to turn the driving section in the robot 1.
The embodiment of the invention is explained in detail above with reference to the drawings. However, a specific configuration is not limited to the embodiment. The specific configuration may be, for example, changed, replaced, or deleted without departing from the spirit of the invention.
The entire disclosure of Japanese Patent Application No. 2017-222633, filed Nov. 20, 2017 is expressly incorporated by reference herein.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-222633 | Nov 2017 | JP | national |
