Small servo driver suitable for robot joint

Abstract

The utility model relates to a small servo driver for robot joints, which comprises a control module, a driving module and an inverter circuit module, the control module is connected with the driving module, the driving module is connected with the inverter circuit module, and the inverter circuit module is connected with the control module through a current sampling module; the inverter circuit module comprises a plurality of NexFET modules and a motor, the motor is respectively connected with the plurality of NexFET modules, and the plurality of NexFET modules are used for reducing grid capacitance and increasing power density; on the basis of a new power device, a servo driver hardware product with an ultra-small size is realized, and the requirements of industries such as joint robots and medical robots are met.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial automation, in particular to a small servo driver suitable for robot joints. Background Art

[0002] The development of robots is getting faster and faster, and the requirements for servo drives are getting higher and higher. Especially in some joint robot equipment, some special occasions require the size of the servo drive to be as small as possible. However, due to the limitation of power devices, this is still the biggest challenge faced by engineers. Utility Model Content

[0003] The purpose of the utility model is to realize a servo driver hardware product with an ultra-small volume to meet the needs of industries such as joint robots and medical robots, and to propose a small servo driver suitable for robot joints.

[0004] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0005] A small servo driver suitable for a robot joint, comprising:

[0006] Control module, drive module and inverter circuit module;

[0007] The control module is connected to the driving module, the driving module is connected to the inverter circuit module, and the inverter circuit module is connected to the control module via a current sampling module;

[0008] The inverter circuit module includes a plurality of NexFET modules and a motor, wherein the motor is connected to the plurality of NexFET modules respectively, and the plurality of NexFET modules are used to reduce gate capacitance and increase power density.

[0009] Preferably, the inverter circuit module includes three NexFET modules, the three NexFET modules are arranged horizontally, and the motor is connected to the three NexFET modules respectively through alternating current.

[0010] Preferably, a resistor R1 is provided between the motor and the first group of NexFET modules.

[0011] Preferably, a resistor R2 is provided between the motor and the third group of NexFET modules.

[0012] Preferably, the control module includes an STM32F103 chip.

[0013] Preferably, the driving module includes a DRV8323 chip.

[0014] Preferably, the first group of NexFET modules includes a MOS transistor Q1 and a MOS transistor Q2.

[0015] Preferably, the third group of NexFET modules includes MOS transistor Q5 and MOS transistor Q6.

[0016] Preferably, the three NexFET modules further include a second group of NexFET modules, and the second group of NexFET modules includes MOS transistor Q3 and MOS transistor Q4.

[0017] Preferably, the MOS transistor Q1 is connected to the MOS transistor Q2, the MOS transistor Q3 is connected to the MOS transistor Q4, the MOS transistor Q5 is connected to the MOS transistor Q6, one end of the MOS transistor Q1 and the MOS transistor Q2 are connected to the MOS transistor Q3 and the MOS transistor Q4 respectively, and one end of the MOS transistor Q3 and the MOS transistor Q4 are connected to the MOS transistor Q5 and the MOS transistor Q6 respectively.

[0018] Compared with the prior art, the power-off detection circuit of the small servo driver for robot joints in the embodiment of the utility model includes: a control module, a drive module and an inverter circuit module, the control module is connected to the drive module, the drive module is connected to the inverter circuit module, and the inverter circuit module is connected to the control module through a current sampling module; the inverter circuit module includes a plurality of NexFET modules and a motor, the motor is respectively connected to the plurality of NexFET modules, and the plurality of NexFET modules are used to reduce gate capacitance and increase power density; because the utility model adopts the NexFET module, combined with the hardware design of other modules, a smaller volume is achieved under the same specifications compared with the existing modules, because the NexFET module adopts high-density patch packaging technology and supports MCU to use a higher switching frequency; in the field of servo drivers, a higher switching frequency can save more conduction losses, thereby achieving lower power consumption. Based on the new power device, a servo driver hardware product with an ultra-small volume is realized to meet the needs of industries such as joint robots and medical robots. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0020] Figure 1 This is a schematic diagram of a small servo driver suitable for robot joints proposed by the utility model;

[0021] Figure 2This is a schematic diagram of the inverter circuit module proposed by the utility model. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0023] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0024] Reference Figure 1 , showing a schematic diagram of a small servo driver suitable for a robot joint according to an embodiment of the utility model, comprising:

[0025] Control module, drive module and inverter circuit module;

[0026] Specifically, the control module is connected to the drive module, the drive module is connected to the inverter circuit module, and the inverter circuit module is connected to the control module via a current sampling module;

[0027] Further applied to the present invention, the inverter circuit module includes multiple NexFET modules and a motor, the motor is connected to the multiple NexFET modules respectively, and the multiple NexFET modules are used to reduce gate capacitance and increase power density.

[0028] Figure 1 The inverter circuit module in the embodiment includes three NexFET modules. The NexFET module is a new type of MOS tube, which is a half-bridge power block, equivalent to integrating the upper bridge and lower bridge MOS tubes in one chip.

[0029] In a preferred embodiment of the utility model, the control module includes an MCU module. Specifically, the MCU module is an STM32F103 chip. Of course, it can also include other types of chips, and the utility model embodiment does not impose too many restrictions on this.

[0030] Furthermore, the driving module includes a DRV8323 chip, which can generate the 3.3V power supply required by the MCU and also integrates a 6-way pre-driving circuit, which can drive 6 MOS tubes, that is, it can drive the above-mentioned three NexFET modules; of course, the driving module can also use other types of chips to achieve the above-mentioned functions, and the embodiments of the utility model do not impose too many restrictions on this.

[0031] In an embodiment of the utility model, the power-off detection circuit of the small servo driver for robot joints includes: a control module, a drive module and an inverter circuit module, the control module is connected to the drive module, the drive module is connected to the inverter circuit module, and the inverter circuit module is connected to the control module through a current sampling module; the inverter circuit module includes multiple NexFET modules and motors, the motors are respectively connected to the multiple NexFET modules, and the multiple NexFET modules are used to reduce gate capacitance and increase power density; on the basis of the new power device, an ultra-small servo driver hardware product is realized to meet the needs of industries such as joint robots and medical robots.

[0032] Reference Figure 2 , showing a schematic diagram of an inverter circuit module of an embodiment of the utility model, including: the inverter circuit module may include three NexFET modules, the three NexFET modules are arranged horizontally, and the motor is connected to the three NexFET modules respectively through alternating current; specifically, the motor is connected to the three NexFET modules respectively through the U-phase wire, V-phase wire, and W-phase wire of the three-phase alternating current; it should be noted that the three NexFET modules are only an example of the embodiment of the utility model, and other numbers of NexFET modules may also be included, such as four NexFET modules or five NexFET modules, etc. The embodiment of the utility model does not impose too many restrictions on the number of NexFET modules.

[0033] In a specific example, Figure 2 As shown, the three NexFET modules may include a first group of NexFET modules, a second group of NexFET modules, and a third group of NexFET modules. A resistor R1 is provided between the motor and the first group of NexFET modules. Further, a resistor R2 is provided between the motor and the third group of NexFET modules. In a preferred embodiment, the first group of NexFET modules includes MOS transistors Q1 and Q2. On the other hand, the third group of NexFET modules includes MOS transistors Q5 and Q6. The second group of NexFET modules includes MOS transistors Q3 and Q4.

[0034] Figure 2 The M in the figure refers to the motor. As a load, the motor converts electrical energy into mechanical energy and realizes the mechanical movement of the robot joints.

[0035] In the embodiment of the utility model, power density refers to the power size per unit volume. If the volume is very small and the power is very large, it means that the power density is very large. In the solution of the present application, because the six MOS tubes form an inverter circuit, the module will have switching losses. If the power is too large, the loss will also be too large, which will cause a lot of heat, further limiting the power density from being too large. In the design requirements of the robot joint, it is required that its dedicated driver power is as large as possible and the volume is as small as possible. However, the greater the power, the larger the gate capacitance of the MOS tube used. This results in a large switching loss of the MOS tube, which also limits the power density. The technical solution of the present application is to use a NexFET module. The NexFET module is a MOS tube. Compared with an ordinary MOS tube, when it outputs the same power, its gate capacitance is very small, which makes the switching loss very small, thereby making it possible to increase the power density.

[0036] In a specific connection manner, the MOS transistor Q1 is connected to the MOS transistor Q2, the MOS transistor Q3 is connected to the MOS transistor Q4, the MOS transistor Q5 is connected to the MOS transistor Q6, one end of the MOS transistor Q1 and the MOS transistor Q2 are connected to the MOS transistor Q3 and the MOS transistor Q4 respectively, and one end of the MOS transistor Q3 and the MOS transistor Q4 are connected to the MOS transistor Q5 and the MOS transistor Q6 respectively.

[0037] like Figure 2 As shown, the technical solution of the present application combines the right-angle power-on method with the lateral power MOSFET, and has a package size that meets industrial standards. It can not only provide a lower on-resistance RDSON, but also requires only an extremely low gate charge, so that the power density of the servo drive is greatly improved, thereby reducing the product size, and can well meet the application occasions such as robots that have requirements on space volume; for example, the chip is a 5mm×6mm SON package to minimize parasitic inductance, while obtaining a lower RDS(ON) in an ultra-small size, and can achieve a minimum conduction loss current of 35A, and a PLoss of 2.4W.

[0038] In the above description of this specification, unless otherwise clearly specified and limited, the terms "fixed", "installed", "connected" or "connected" should be understood in a broad sense. For example, with regard to the term "connection", it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. Therefore, unless otherwise clearly defined in this specification, those skilled in the art can understand the specific meanings of the above terms in this utility model according to the specific circumstances.

[0039] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "length", "width", "thickness", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "center", "longitudinal", "lateral", "clockwise" or "counterclockwise", etc., which indicate the orientation or position relationship, are based on the orientation or position relationship shown in the drawings of this specification, and are only for the purpose of facilitating the explanation of the scheme of the utility model and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operate in a specific orientation. Therefore, the above-mentioned orientation or position relationship terms cannot be understood or interpreted as limitations on the scheme of the utility model.

[0040] In addition, the terms "first" or "second" used in this specification to refer to numbers or ordinals are only used for descriptive purposes and cannot be understood as explicitly or implicitly indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, the meaning of "plurality" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

[0041] Although this specification has shown and described a plurality of embodiments of the utility model, it is obvious to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will think of many changes, modifications and alternatives without departing from the idea and spirit of the utility model. It should be understood that in the process of practicing the utility model, various alternatives to the embodiments of the utility model described herein may be adopted. The attached claims are intended to define the scope of protection of the utility model, and therefore cover the modular composition, equivalent or alternatives within the scope of these claims.

Claims

1. A small servo driver suitable for robot joints, characterized in that: include: Control module, drive module and inverter circuit module; The control module is connected to the driving module, the driving module is connected to the inverter circuit module, and the inverter circuit module is connected to the control module via a current sampling module; The inverter circuit module includes a plurality of NexFET modules and a motor, wherein the motor is connected to the plurality of NexFET modules respectively, and the plurality of NexFET modules are used to reduce gate capacitance and increase power density.

2. The small servo driver suitable for robot joints according to claim 1, characterized in that: The inverter circuit module includes three NexFET modules, the three NexFET modules are arranged horizontally, and the motor is connected to the three NexFET modules respectively through alternating current.

3. The small servo driver suitable for robot joints according to claim 2, characterized in that: A resistor R1 is provided between the motor and the first group of NexFET modules.

4. The small servo driver suitable for robot joints according to claim 3, characterized in that: A resistor R2 is provided between the motor and the third group of NexFET modules.

5. The small servo driver suitable for robot joints according to claim 1, characterized in that: The control module includes an STM32F103 chip.

6. The small servo driver suitable for robot joints according to claim 1, characterized in that: The driving module includes a DRV8323 chip.

7. The small servo driver suitable for robot joints according to claim 4, characterized in that: The first group of NexFET modules includes a MOS transistor Q1 and a MOS transistor Q2.

8. The small servo driver suitable for robot joints according to claim 7, characterized in that: The third group of NexFET modules includes MOS transistor Q5 and MOS transistor Q6.

9. The small servo driver suitable for robot joints according to claim 8, characterized in that: The three NexFET modules further include a second group of NexFET modules, and the second group of NexFET modules includes a MOS transistor Q3 and a MOS transistor Q4.

10. The small servo driver suitable for robot joints according to claim 9, characterized in that: The MOS transistor Q1 is connected to the MOS transistor Q2, the MOS transistor Q3 is connected to the MOS transistor Q4, the MOS transistor Q5 is connected to the MOS transistor Q6, one end of the MOS transistor Q1 and the MOS transistor Q2 are connected to the MOS transistor Q3 and the MOS transistor Q4 respectively, and one end of the MOS transistor Q3 and the MOS transistor Q4 are connected to the MOS transistor Q5 and the MOS transistor Q6 respectively.

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