Computer system, vehicle, method and storage medium for detecting and controlling relative position of two rotating eccentric shafts

Abstract

The invention relates to a computer system for detecting and controlling the relative position of two rotating eccentric shafts, a vehicle, a method and a storage medium, in particular to a computer system (80) for detecting and controlling the relative position of two rotating eccentric shafts (50, 60), comprising a processing circuit (82), the processing circuit (82) is configured to: calculate a pilot motor quadrature current of a pilot motor (30) driving a first eccentric shaft (50); calculating a following motor quadrature current of a following motor (40) driving the second eccentric shaft (60); determining, in real time, a phase angle between the pilot motor quadrature current and the follower motor quadrature current; modifying the rotational speed of the following motor (40) such that it is equal to the rotational speed of the guide motor (30); and modifying the rotational speed of the following motor (40) to adjust the phase angle to be equal to a main target phase angle when the rotational speed of the following motor (40) is equal to the rotational speed of the guide motor (30).

Description

Technical Field

[0001] The present disclosure relates generally to construction vehicles and more particularly to vibratory compactors. In particular aspects, the present disclosure relates to a computer system for synchronizing a lead motor and a follower motor, a vehicle including such a computer system, a method, and a storage medium for performing such a method. The present disclosure may be applied to heavy vehicles such as trucks, buses, and construction equipment, among other vehicle types. Although the present disclosure may be described with respect to a particular vehicle, the present disclosure is not limited to any particular vehicle. Background Art

[0002] A vibratory compactor (also called a roller compactor) uses one or more cylindrical drums (usually two) to compact a substrate, such as soil or asphalt. The cylindrical drum usually includes an eccentric shaft that rotates to vibrate the drum, thereby improving compaction efficiency. However, this results in disturbances to the surrounding environment, especially noise due to vibration, which depends on the relative position of the eccentric shaft. Therefore, it is necessary to control the relative position of the eccentric shaft. Summary of the invention

[0003] According to a first aspect of the present disclosure, the present invention relates to a computer system for detecting and controlling the relative position of two rotating eccentric shafts, the computer system comprising a processing circuit, the processing circuit being configured to: - calculating a lead motor quadrature current for a lead motor driving a first of the two eccentric shafts; - calculating a follower motor quadrature current for a follower motor driving a second eccentric shaft of the two eccentric shafts; - determining in real time the phase angle between the leading motor quadrature current and the following motor quadrature current; - modifying the rotation speed of the follower motor through closed-loop control so that the rotation speed of the follower motor is equal to the rotation speed of the lead motor; - When the rotation speed of the follower motor is equal to the rotation speed of the lead motor, modify the rotation speed of the follower motor to adjust the phase angle to be equal to the main target phase angle. A first aspect of the present disclosure may seek to detect and control the relative position of two rotating eccentric shafts in order to control the amount and timing of noise generated by the vibrations of the eccentric shafts. Technical benefits may include reducing the noise generated by the eccentric shaft or coordinating the impact of multiple rollers.

[0004] Optionally, in some examples, including in at least one preferred example, the processing circuit is further configured to: - modifying the rotation speed of the follower motor by closing the control loop to adjust the phase angle to be equal to the auxiliary target phase angle; and - When the phase angle is equal to the auxiliary target phase angle, and when the speed of the follower motor is equal to the speed of the lead motor, modifying the speed of the follower motor to adjust the phase angle to be equal to the primary target phase angle. Technical benefits may include more efficient position control.

[0005] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: in addition to modifying the rotational speed of the follower motor, modify the rotational speed of the lead motor to adjust the phase angle to be equal to the main target phase angle. Technical benefits may include faster and more efficient adjustment of the phase angle.

[0006] Optionally, in some examples, including at least one preferred example, the processing circuit is further configured to: when the phase angle is equal to the main target phase angle, control the speed of the lead motor and / or the follower motor to maintain the phase angle equal to the main target phase angle. Technical benefits may include maintaining the main target phase angle during subsequent use of the eccentric shaft.

[0007] Optionally, in some examples, including at least one preferred example, the processing circuit is configured to: determine the phase angle between the leading motor quadrature current and the following motor quadrature current through a phase locked loop. Technical benefits may include efficient phase angle determination.

[0008] According to a second aspect of the disclosure, the invention relates to a vehicle including the aforementioned computer system. The second aspect of the invention may seek to achieve relative position control of two eccentric shafts from the vehicle. Technical benefits may include easy and effective relative position control of two eccentric shafts from the vehicle to reduce vibrations generated by the eccentric shafts.

[0009] Optionally, in some examples, including in at least one preferred example, the vehicle further comprises: - Leading and following motors; and - A first roller and a second roller, the first roller including a first eccentric shaft and the second roller including a second eccentric shaft, the first eccentric shaft being connected to the lead motor, the lead motor being configured to drive the first eccentric shaft, and the second eccentric shaft being connected to the follower motor, the follower motor being configured to drive the second eccentric shaft. Technical benefits may include performing relative position control of the eccentric shafts of the vehicle.

[0010] Optionally, in some examples, including at least one preferred example, at least one of the lead motor and the follower motor is a brushless DC motor. Technical benefits may include more efficient motor current calculations and more robust motors.

[0011] According to a third aspect of the present disclosure, the present invention relates to a computer-implemented method for detecting and controlling the relative position between two rotating eccentric shafts, the method comprising: - calculating, by a processing circuit of a computer system, a lead motor quadrature current for a lead motor driving a first eccentric shaft of the two eccentric shafts; - calculating, by the processing circuit, a follower motor quadrature current of a follower motor, the follower motor driving a second eccentric shaft of the two eccentric shafts; - determining in real time, by means of the processing circuit, the phase angle between the quadrature current of the leading motor and the quadrature current of the following motor; - modifying the rotation speed of the follower motor to be equal to the rotation speed of the lead motor by means of a closed loop control included in the processing circuit; and - When the rotation speed of the follower motor is equal to the rotation speed of the lead motor, the rotation speed of the follower motor is modified by the processing circuit to adjust the phase angle to be equal to the main target phase angle.

[0012] A third aspect of the present disclosure may seek to implement a method of detecting and controlling the relative position of two rotating eccentric shafts. Technical benefits may include having a method of reducing noise generated by the eccentric shaft and the vibrating drum.

[0013] Optionally, in some examples, including in at least one preferred example, the method further comprises: - modifying the rotation speed of the following motor by closing the control loop to adjust the phase angle to be equal to the auxiliary target phase angle; - When the phase angle is equal to the auxiliary target phase angle, and when the speed of the follower motor is equal to the speed of the lead motor, modifying the speed of the follower motor to adjust the phase angle to be equal to the primary target phase angle. Technical benefits may include more efficient position control.

[0014] Optionally, in some examples, including at least one preferred example, in addition to modifying the rotational speed of the follower motor, the method further includes: modifying the rotational speed of the lead motor to adjust the phase angle to be equal to the main target phase angle. Technical benefits may include faster and more efficient adjustment of the phase angle between the two eccentric shafts.

[0015] Optionally, in some examples, including at least one preferred example, the phase angle is determined by a phase locked loop.Technical benefits may include efficient phase angle determination.

[0016] Optionally, in some examples, including at least one preferred example, the rotational speed of the lead motor is equal to the initial rotational speed. Technical benefits may include better detection and control of the relative position of two eccentric shafts rotating at the same speed.

[0017] Optionally, in some examples, including at least one preferred example, the initial rotation speed is equal to or lower than 240 rpm, preferably lower than 60 rpm. Technical benefits may include more accurate calculation of the lead motor quadrature current and the follower motor quadrature current, thereby indicating the eccentric position.

[0018] Optionally, in some examples, including at least one preferred example, when the primary target phase angle is reached, the speed of the lead motor and the follower motor is modified to a final speed. Technical benefits may include having a final speed that is optimal for noise cancellation and / or vibration generation.

[0019] Optionally, in some examples, including at least one preferred example, the final rotational speed is equal to or greater than 1000 rpm, preferably equal to 4800 rpm. Technical benefits may include having a final rotational speed that is optimal for vibration generation required to meet compaction requirements.

[0020] Optionally, in some examples, including at least one preferred example, the method further comprises: controlling the rotational speeds of the lead motor and the follower motor to maintain the phase angle equal to the primary target phase angle. Technical benefits may include maintaining a constant phase angle and keeping a constant vibration level while maintaining good compaction efficiency.

[0021] Optionally, in some examples, including at least one preferred example, the method further comprises controlling the speed of the lead motor and / or the follower motor to maintain a final speed. Technical benefits may include constant vibration generation.

[0022] According to a fourth aspect of the present disclosure, the present invention relates to a computer program product comprising program code for performing the aforementioned method when executed by a processing circuit.

[0023] A fourth aspect of the present disclosure may seek to detect and control the relative position of two rotating eccentric shafts in order to control the amount of noise generated by the eccentric shafts rotating within their respective drums.Technical benefits may include physically implementing the above method.

[0024] According to a fifth aspect of the present disclosure, the present invention relates to a non-transitory computer-readable storage medium comprising instructions, which, when executed by a processing circuit, cause the processing circuit to perform the above method.

[0025] A fifth aspect of the present disclosure may seek to detect and control the relative position of two rotating eccentric shafts in order to control the amount of noise generated by the eccentric shafts rotating within their respective drums.Technical benefits may include physically implementing the above method in a long term storage medium.

[0026] As will be apparent to one of ordinary skill in the art, the disclosed aspects, examples (including any preferred examples), and / or the appended claims may be appropriately combined with each other. Additional features and advantages are disclosed in the following description, claims, and drawings, and some features and advantages will become apparent to those skilled in the art, or will be recognized by practicing the disclosure described herein.

[0027] This document also discloses a computer system, a control unit, a code module, a computer-implemented method, a computer-readable medium, and a computer program product associated with the above technical benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Examples are described in more detail below with reference to the accompanying drawings.

[0029] Figure 1 is a perspective view of an exemplary vehicle according to an example.

[0030] Figure 2 yes Figure 1 Sectional view of the compactor along plane II.

[0031] Figure 3 is a schematic diagram of an exemplary computer system for implementing the examples disclosed herein, according to an example.

[0032] Figure 4 is a flow chart of an exemplary method for detecting and controlling the relative position of two rotating eccentric shafts according to an example. DETAILED DESCRIPTION

[0033] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.

[0034] Figure 1 An exemplary vehicle is shown, for example, as a roller compactor 1. The roller compactor 1 is used, for example, for compacting a substrate such as soil, sand or asphalt at a construction site. The roller compactor 1 is located on a ground surface 3, which is considered to be horizontal for the purpose of this description only. The roller compactor 1 comprises a cab 5, a first drum 10, a second drum 20 and a frame 25.

[0035] In a variant that is not shown, the roller compactor comprises more than two drums.

[0036] A transverse direction X, a forward direction Y and a height direction Z which are perpendicular to one another are defined relative to the roller compactor 1. The height direction Z is considered to be vertical.

[0037] When driving or operating the roller compactor 1 , a driver or operator is usually located in the cab 5 .

[0038] exist Figure 1 In the example of FIG. 1 , the first roller 10 and the second roller 20 are cylindrical, but may also have other shapes, such as a tapered cylinder. The first roller 10 and the second roller 20 may be similar, for example, in diameter and weight, or may have different diameters and weights. The first roller 10 and the second roller 20 include a first motor 11 and a second motor 21, respectively. Figure 2 As can be seen from the figure, the first motor 11 drives the first roller 10 to rotate around the first roller axis X10, and the corresponding second motor 21 drives the corresponding second roller 20 to rotate around the corresponding second roller axis X20. In the example of the drawings, the first roller axis X10 and the second roller axis X20 are parallel to the transverse direction X and parallel to each other.

[0039] The first roller 10 and the second roller 20 respectively include a first surface 13 and a second surface 23. The first surface 13 and the second surface 23 are in contact with the ground 3 and / or the substrate to be compacted.

[0040] The frame 25 partially surrounds the first roller 10 and the second roller 20 so that they are connected to the rest of the roller compactor 1. The frame 25 can also be used to protect a user from the first roller 10 and the second roller 20, for example to prevent the user from contacting the rollers 10 and 20, or from protruding parts of the substrate being compacted.

[0041] Reference Figure 2 The roller compactor 1 further includes a guide motor 30 and a follower motor 40. The guide motor 30 and the follower motor 40 are respectively located in the first roller 10 and the second roller 20. The guide motor 30 and the follower motor 40 are electric motors. Figure 1 In the example of the embodiment of the present invention, a brushless DC motor is used. When the leading motor 30 and the following motor 40 are in operation, they are supplied with a DC current (not shown) from a battery, which is advantageously converted into a three-phase current. This conversion is well known and therefore will not be explained in detail.

[0042] As a variant that is not shown, one or both of the lead motor and the follower motor may be different types of electric motors, such as induction motors, brushed motors or brushless DC motors.

[0043] The roller compactor 1 further comprises a first eccentric shaft 50 and a second eccentric shaft 60. The first eccentric shaft 50 is located inside the first roller 10 and extends along the first roller axis X10. In some examples not shown, the first eccentric shaft is offset from the first roller axis. The first eccentric shaft 50 comprises a first eccentric body 51 fixed to the first eccentric shaft 50. The first eccentric body 51 is, for example, a metal block. In some examples, the first eccentric body 51 is formed integrally with the first eccentric shaft 50.

[0044] When the guide motor 30 is in operation, it drives the first eccentric shaft 50 (wherein the first eccentric body 51 is fixed to the first eccentric shaft 50) so that they rotate around the first drum axis X10. This rotation of the first eccentric shaft 50 causes the first drum 10 to vibrate along the height direction Z, which increases the compaction power of the first drum 10.

[0045] In a similar manner to the first eccentric shaft 50, the second eccentric shaft 60 is located in the second roller 20 and extends along the second roller axis X20. In some examples not shown, the second eccentric shaft is offset from the second roller axis. The second eccentric shaft 60 includes a second eccentric body 61, which is fixed to the second eccentric shaft 60. The second eccentric body 61 is, for example, a metal block. In some examples, the second eccentric body 61 is formed integrally with the second eccentric shaft 60. In some examples, the second eccentric body 60 has the same mass as the mass of the first eccentric body 50.

[0046] When the follower motor 40 rotates, it drives the second eccentric shaft 60 (wherein the second eccentric body 61 is fixed to the second eccentric shaft 60 ) so that they rotate around the second roller axis X20 , causing the second roller 20 to vibrate along the height direction Z, thereby increasing the compaction power of the second roller 20 .

[0047] In some examples not shown, the lead motor is located in the second drum and the follower motor is located in the first drum. In this case, the lead motor drives the second eccentric shaft and the follower motor drives the first eccentric shaft.

[0048] The vibrations of the first roller 10 and the second roller 20 may cause disturbances to the surroundings of the roller compactor 1, in particular may generate unpleasant noises for the driver or operator as well as third parties near the roller compactor 1. In order to control the vibrations, in particular to limit the noise generated by the vibrations of the rollers 10 and 20, the roller compactor 1 may also include angular position sensors 71, 72, current sensors 75 and 76 and a computer system 80.

[0049] The sensors 71 and 72 may be Hall probes, and in particular, each sensor 71 and 72 may be an array of three Hall probes. The sensor 71 is configured to detect the angular position of the lead motor 30 , and the sensor 72 is configured to detect the angular position of the follower motor 40 .

[0050] The current sensors 75 and 76 measure the intensity of the current supplied to the lead motor 30 and the follower motor 40, respectively. In some examples, the current sensors 75 and 76 measure the intensity of the three-phase current supplied to the lead motor 30 and the follower motor 40, respectively.

[0051] Figure 3is a schematic diagram of a computer system 80 for implementing the examples disclosed herein. The computer system 80 is suitable for executing instructions from a computer-readable medium to perform these and / or any functions or processes described herein. The computer system 80 can be connected (e.g., networked) to other machine components in a LAN, an intranet, an extranet, or the Internet. Although only a single device is shown, the computer system 80 may include any collection of devices that individually or jointly execute one or more sets of instructions to perform any one or more methods discussed herein. Therefore, any reference to a computer system, a computing system, a computer device, a computing device, a control system, a control unit, an electronic control unit (ECU), a processor device, a processing circuit, etc. in the present disclosure and / or claims includes a reference to one or more such devices to individually or jointly execute one or more sets of instructions to perform any one or more of the methods discussed herein. For example, a control system may include a single control unit or multiple control units connected to each other or otherwise communicatively coupled, so that any executed functions can be distributed between the control units as needed. In addition, such devices can communicate with each other or other devices through various system architectures (e.g., directly or via a controller area network (CAN) bus, etc.).

[0052] The computer system 80 may include at least one computing device or electronic device that can include firmware, hardware and / or execute software instructions to implement the functions described herein. The computer system 80 may include a processing circuit 82, such as a processing circuit including one or more processor devices or control units, a memory 84, and a system bus 86. The computer system 80 may include at least one computing device with a processing circuit 82. The system bus 86 provides an interface for system components including (but not limited to) memory 84 and processing circuit 82. The processing circuit 82 may include any number of hardware components for performing data or signal processing or for executing computer codes stored in the memory 84. The processing circuit 82 may include, for example, a general-purpose processor, a special-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a circuit containing a processing component, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic devices designed to perform the functions described herein, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The processing circuit 82 may also include computer executable code that controls the operation of a programmable device.

[0053] The system bus 86 can be any of several types of bus structures, which can be further interconnected to a memory bus with or without a memory controller, a peripheral bus, and / or a local bus using any of a variety of bus architectures. The memory 84 can be one or more devices for storing data and / or computer code for completing or facilitating the methods described herein. The memory 84 can include a database component, an object code component, a script component, or other types of information structures for supporting various activities herein. Any distributed or local memory device can be used in conjunction with the system and method of the present specification. The memory 84 can be communicatively connected to the processing circuit 82, for example, via a circuit or any other wired, wireless, or network connection, and can include computer code for performing one or more processes described herein. The memory 84 may include nonvolatile memory 88, such as read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc., and volatile memory 90, such as random access memory (RAM), or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a computer or other machine having the processing circuit 82. A basic input / output system (BIOS) 92 may be stored in the nonvolatile memory 88 and may include basic routines that help transfer information between elements within the computer system 80.

[0054] The computer system 80 may also include or be coupled to non-transitory computer-readable storage media, such as a storage device 94, which may include, for example, an internal or external hard disk drive (HDD) such as an enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA), flash memory, etc. The storage device 94 and other drives associated with computer-readable and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, and the like.

[0055] Hard-coded or soft-coded computer code may be provided in the form of one or more modules. Modules may be implemented as software and / or hard-coded in circuits to implement the functions described herein in whole or in part. Modules may be stored in storage device 94 and / or volatile memory 90, which may include an operating system 95 and / or one or more program modules 96. All or part of the examples disclosed herein may be implemented as a computer program 97 stored on a temporary or non-temporary computer-usable or computer-readable storage medium (e.g., a single medium or multiple media, such as storage device 94), which includes complex programming instructions, such as complex computer-readable program code, to enable processing circuit 82 to perform the actions described herein. Therefore, the computer-readable program code of computer program 97 may include software instructions for implementing the functions of the examples described herein when executed by processing circuit 82. In some examples, storage device 94 may be an analog or digital computer program product, such as a readable storage medium on which computer program 97 is stored, wherein at least a portion of computer program 97 may be loaded into a processor, for example, for implementing the functions of the examples described herein when executed by processing circuit 82. Processing circuitry 82 may serve as a controller or control system for computer system 80 for implementing the functionality described herein.

[0056] The computer system 80 may include an input device interface 98 configured to receive input and selections to be transmitted to the computer system 80 when executing instructions such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices can be connected to the processing circuit 82 through the input device interface 98 coupled to the system bus 86, but can also be connected through other interfaces, such as a parallel port, an Institute of Electrical and Electronics Engineers (IEEE) 1394 serial port, a universal serial bus (USB) port, an IR interface, etc. The computer system 80 may include an output device interface 99, which is configured to forward output to, for example, a display, a video display unit (such as a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 80 may include a communication interface 100 suitable for communicating with a network when appropriate or desired.

[0057] The operational actions described in any exemplary aspect of this article are described to provide examples and discussions. These actions can be performed by hardware components, can be implemented in machine executable instructions to make a processor perform these actions, or can be performed by a combination of hardware and software. Although a specific order of method actions may be shown or described, the order of these actions can vary. In addition, two or more actions can be performed simultaneously or partially simultaneously.

[0058] When the leading motor 30 and the following motor 40 are supplied with direct current by the battery, the computer system 80 (more specifically, the processing circuit 82) receives the angular position values ​​measured by the position sensors 71 and 72 and the current values ​​measured by the current sensors 75 and 76. The computer system 80 (more specifically, the processing circuit 82) is configured to calculate the leading motor quadrature current I q1 and the follower motor quadrature current I of the follower motor 40 q2 , more specifically, the calculation is performed by using the position value and the current value. The calculation can be performed by Park transform.

[0059] In some embodiments, the processing circuit 82 includes a circuit for calculating the guide motor quadrature current I q1 The first submodule is used to calculate the orthogonal current I of the follower motor q2 The first submodule may be integrated in the leading motor, and the second submodule may be integrated in the following motor.

[0060] The guide motor quadrature current I q1 It depends on the friction force, gravity and centrifugal force applied to the guide motor 30 and the torque output by the guide motor 30 .

[0061] When the guide motor 30 rotates at a low speed, such as 60 revolutions per minute or rpm and below, the friction and centrifugal force are negligible, and the guide motor quadrature current I q1 is approximately proportional to the torque output by the guide motor 30. When the guide motor 30 drives the first eccentric shaft 50, the torque output by the guide motor 30 is not constant but varies sinusoidally. When the first eccentric shaft 50 is at the point closest to the ground 3 in the rotation around the first axis X10 measured along the height direction Z, the output is proportional to the maximum guide motor quadrature current I q1 When the first eccentric shaft 50 is at the point farthest from the ground 3 measured along the height direction Z and rotating around the first axis X10, the output is orthogonal to the minimum guide motor current I q1 Therefore, the guide motor quadrature current I q1 It is directly related to the angular position of the first eccentric shaft 50 .

[0062] This also applies to the follower motor quadrature current I q2, which is also approximately proportional to the torque output by the follower motor 40 and also changes sinusoidally. Therefore, the follower motor quadrature current I q2 It is directly related to the angular position of the second eccentric shaft 60 .

[0063] If no specific position control is performed, the angular position of the first eccentric shaft 50 is independent of the angular position of the second eccentric shaft 60. In the example shown in the figure, by determining the pilot motor quadrature current I q1 The quadrature current I q2 The relative positions of the two eccentric shafts 50 and 60 are monitored by using the phase angle Φ therebetween.

[0064] The processing circuit 82 is configured to determine the phase angle Φ in real time. This is done, for example, by using a phase locked loop or by calculating the first motor quadrature current I q1 and the follower motor quadrature current I q2 It is performed by cross correlation between them.

[0065] The processing circuit 82 is further configured to modify the speed of the follower motor 40 to be equal to the speed of the lead motor 30. This is accomplished by a closed loop control included in the processing circuit 82. In some examples, the closed loop is a proportional, integral, derivative controller.

[0066] “Two angles are equal” means that there is a difference of one degree or less between the two angles. When the rotation speed of the follower motor 40 is equal to the rotation speed of the lead motor 30, the processing circuit 82 is further configured to modify the rotation speed of the follower motor 40 to adjust the phase angle Φ to be equal to the main target phase angle Φ2.

[0067] In some examples, the processing circuit 82 is further configured to modify the rotation speed of the follower motor 40 to adjust the phase angle Φ to be equal to the auxiliary target phase angle Φ1 through a closed control loop. In this case, when the rotation speed of the follower motor 40 is equal to the rotation speed of the lead motor 30 (as described above) and the phase angle Φ is equal to the auxiliary target phase angle Φ1, the rotation speed of the follower motor 40 is modified to adjust the phase angle Φ to be equal to the main target phase angle Φ2.

[0068] The auxiliary target phase angle Φ1 is, for example, equal to zero degrees. The main target phase angle Φ2 is typically different from the auxiliary target phase angle Φ1, but in some examples can be equal to the auxiliary target phase angle Φ1. In some examples, the main target phase angle Φ2 is determined by an algorithm (e.g., a noise elimination algorithm) that determines which value of the main target phase angle Φ2 reduces the most noise caused by the vibration of the first drum 10 and the second drum 20.

[0069] In some examples, the processing circuit 82 is further configured to eliminate the first motor quadrature current I q1 and the follower motor quadrature current I q2 The random phase angle differences between φ and φ may be considered as noise and are, for example, due to the movement of the roller compactor 1 or due to environmental disturbances of the lead motor 30 and / or the follower motor 30 .

[0070] In some examples, the processing circuit 82 is configured to modify the rotational speeds of both the follower motor 40 and the lead motor 30 to adjust the phase angle Φ to be equal to the auxiliary target phase angle Φ1 and the main target phase angle Φ2 .

[0071] Now refer to Figure 4 A method for detecting and controlling the relative position of the first rotating eccentric shaft 50 and the second rotating eccentric shaft 60 is described. The method is implemented by the processing circuit 82 of the computer system 80.

[0072] The driver or operator starts the roller compactor 1, in particular by commanding the battery to supply DC current to the lead motor 30 and the follower motor 40. The lead motor 30 is commanded to rotate at an initial speed. In some examples, the initial speed is equal to or lower than 150 rpm, preferably lower than 60 rpm. In step 200, the processing circuit 82 commands the follower motors 30 and 40 to rotate at a first speed.

[0073] In step 202, the processing circuit 82 compares the rotational speeds of the leading motor 30 and the following motor 40. If the rotational speeds are not equal, step 200 is performed again. In this case, when executing step 200, the processing circuit 82 modifies the first rotational speed of the following motor 40 so that it is first different from the previous first rotational speed.

[0074] If the rotational speeds are equal, in other words, the first rotational speed of the follower motor 40 is equal to the initial rotational speed, step 204 is executed.

[0075] The processing circuit 82 receives the angular positions of the first eccentric shaft 50 and the second eccentric shaft 60 and the three-phase current intensity provided to the leading motor 30 and the following motor 40 from the position sensors 71 , 72 and the current sensors 75 and 76 , respectively.

[0076] In step 204, the processing circuit 82 calculates the guide motor quadrature current I q1 , the guide motor quadrature current I q1 This allows the position of the first eccentric shaft 50 to be detected.

[0077] In step 206, the processing circuit 82 calculates the guide motor quadrature current I q2 , the guide motor quadrature current I q1This allows detecting the position of the second eccentric shaft 60. In particular, the processing circuit 82 uses this position and the current intensity value to perform steps 204 and 206. Steps 204 and 206 are performed in real time.

[0078] In step 208, the processing circuit 82 determines in real time a phase angle Φ related to the relative positions of the first eccentric shaft 50 and the second eccentric shaft 60. As previously described, in some examples, the phase angle Φ is determined by a phase locked loop included in the processing circuit 82 or by cross correlation.

[0079] In step 210, the processing circuit 82 compares the phase angle Φ with the auxiliary target phase angle Φ1. If the phase angle Φ is not equal to the auxiliary target phase angle Φ1, the processing circuit 82 performs steps 200 to 208 again. In this case, when executing step 200, the processing circuit 82 modifies the first rotational speed of the follower motor 40 so that it first differs from the previous first rotational speed to modify the phase angle Φ in order to obtain an updated phase angle Φ. Step 202 ensures that the first rotational speed of the follower motor 40 becomes equal to the initial rotational speed again. This is particularly advantageous for maintaining the updated phase angle Φ constant.

[0080] The modification of the first rotation speed in step 200 is performed by a closed-loop control included in the processing circuit 82. In some examples, the closed-loop control is a proportional, integral, derivative controller included in the processing circuit 82.

[0081] In some examples, during step 200 to step 210, the processing circuit 82 maintains the rotation speed of the lead motor 30 equal to the initial rotation speed. “Equal to the rotation speed” means that the rotation speed of the lead motor 30 and / or the follower motor 40 is equal to the rotation speed, which is approximately 5 rpm.

[0082] If the phase angle Φ is equal to the auxiliary target phase Φ1, the first eccentric shaft 50 and the second eccentric shaft 60 are synchronized. Then the phase angle Φ is adjusted to be equal to the main target phase angle Φ2. To this end, the processing circuit 82 performs step 212. In step 212, the processing circuit 82 modifies the rotation speed of the follower motor 40. In step 212, the rotation speed of the follower motor 30 is maintained at or below 240 rpm. In some examples, step 212 is performed by closed-loop control.

[0083] Steps 200 to 212 are performed at the first speed to facilitate the position control, because at the first speed, the first motor quadrature current I q1 and the following motor quadrature current I q2Proportional to the torque, the torque is directly related to the position of the first eccentric shaft 50 and the second eccentric shaft 60, and disturbances due to, for example, centrifugal forces and friction are negligible. Therefore, the position detection and control is more effective at the first rotational speed than at higher rotational speeds, particularly for compacting the substrate.

[0084] In step 214 , the processing circuit 82 compares the phase angle Φ to the primary target phase angle Φ2 . Since the phase angle Φ is calculated in real time, the phase angle Φ is updated to reflect the modification of the rotational speed of the follower motor 40 .

[0085] If the phase angle Φ is not equal to the main target phase angle Φ2 , the processing circuit 82 executes step 212 again to adjust the rotation speed of the follower motor 40 .

[0086] If the phase angle Φ is equal to the main target phase angle Φ2, the processing circuit 82 performs step 216. In step 216, the processing circuit 82 modifies the speed of the lead motor 30 and the follower motor 40 to a final speed. The final speed is greater than the initial speed, and the final speed is a speed for compacting the substrate. In some examples, the final speed is equal to or greater than 1000 rpm, preferably equal to or greater than 4800 rpm. In some examples, step 216 is performed by a proportional, integral, differential, and feedforward controller included in the processing circuit 82.

[0087] Once step 216 is performed, as long as the first drum 10 and the second drum 20 are in operation, the processing circuit 82 preferably maintains the leading motor 30 and / or the following motor 40 rotating at the final speed and the phase angle Φ equal to the main target phase angle Φ2. In some examples, in order to maintain the phase angle Φ equal to the main target phase angle Φ2, the processing circuit 82 may change the speed of the leading motor 30 and / or the following motor 40 so that it has an instantaneous difference from the final speed.

[0088] In some examples, it is not verified whether the phase angle Φ is equal to the secondary target phase angle Φ1, in other words, step 204 is not performed. In this case, step 212 is also not performed. Instead, after completing step 208, step 214 is directly performed. If the phase angle Φ is not equal to the primary target phase angle Φ2, the processing circuit 82 performs step 200 again.

[0089] In some examples, the speeds of both the lead motor 30 and the follower motor 40 are modified in steps 200, 212, and 216. The modification of the speed of the lead motor 30 may be controlled by a closed loop (eg, a proportional, integral, derivative controller included in the processing circuit 82).

[0090] Preferably, steps 200 to 216 are performed in less than 5 seconds, preferably in less than 3 seconds.

[0091] In an example not shown, the leading motor and the following motor are brushed DC motors or motors that directly use DC current without converting it into a three-phase current. In this case, the first motor quadrature current and the following motor quadrature current are equal to the supply current received by the leading motor and the following motor.

[0092] In an example not shown, the position difference between the lead motor and the follower motor is also used to calculate the motor phase angle, and the processing circuit uses this position difference in addition to the phase angle when modifying the speed of the follower motor to achieve the first target phase angle and the main target phase angle. This allows to better take into account the difference between the angular position of these motors and the eccentric shaft when modifying the rotation speed of the lead motor and the follower motor, which difference may be caused by the vibration of the eccentric shaft.

[0093] Example 1: A computer system (80) for detecting and controlling the relative position of two rotating eccentric shafts (50, 60), the computer system (80) comprising a processing circuit (82), the processing circuit being configured to: - calculating the guide motor quadrature current (I q1 ); - calculating a follower motor quadrature current (I q2 ); - Determine the pilot motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) between the phase angle (Φ); - modifying the rotation speed of the follower motor (40) by closed-loop control so that it is equal to the rotation speed of the lead motor (30); and - When the rotation speed of the following motor (40) is equal to the rotation speed of the leading motor (30), the rotation speed of the following motor (40) is modified to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0094] Example 2: The computer system (80) of Example 1, wherein the processing circuit (82) is further configured to: - modifying the rotation speed of the follower motor (40) by closing the control loop to adjust the phase angle (Φ) to be equal to the auxiliary target phase angle (Φ1); - when the phase angle (Φ) is equal to the auxiliary target phase angle (Φ1), and when the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), modifying the rotation speed of the follower motor (40) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0095] Example 3: A computer system (80) according to any one of Examples 1 and 2, wherein the processing circuit (82) is further configured to: in addition to modifying the rotational speed of the follower motor (40), also modify the rotational speed of the guide motor (30) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0096] Example 4: A computer system (80) according to any one of Examples 1 to 3, wherein the processing circuit (82) is further configured to: when the phase angle (Φ) is equal to the main target phase angle (Φ2), control the rotation speed of the guide motor (30) and / or the follower motor (40) to maintain the phase angle (Φ) equal to the main target phase angle (Φ2).

[0097] Example 5: The computer system (80) according to any one of Examples 1 to 4, wherein the processing circuit (82) is configured to: determine the guide motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) is the phase angle (Φ) between them.

[0098] Example 6: A vehicle (1) comprising the computer system (80) of any one of Examples 1 to 5.

[0099] Example 7: The vehicle (1) according to Example 6, further comprising: - a leading motor (30) and a following motor (40); and - a first roller (10) and a second roller (20), the first roller (10) comprising a first eccentric shaft (50), and the second roller (20) comprising a second eccentric shaft (60), the first eccentric shaft (50) being connected to the guide motor (30), the guide motor (30) being configured to drive the first eccentric shaft (50), and the second eccentric shaft (60) being connected to the follower motor (40), the follower motor (40) being configured to drive the second eccentric shaft (60).

[0100] Example 8: The vehicle (1) according to any one of Examples 6 and 7, wherein at least one of the lead motor (30) and the follower motor (40) is a brushless DC motor.

[0101] Example 9: A computer-implemented method for detecting and controlling the relative position of two rotating eccentric shafts (50, 60), the method comprising: - calculating (204) the pilot motor quadrature current (I q1 ), the guide motor (30) drives the first eccentric shaft (50) of the two eccentric shafts (50, 60); - calculating (206) the follower motor quadrature current (I q2 ), the follower motor (40) drives the second eccentric shaft (60) of the two eccentric shafts (50, 60); - determining (208) the guide motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) between the phase angle (Φ); - modifying (200) the rotation speed of the follower motor (40) by means of a closed-loop control included in the processing circuit (82) to adjust the phase angle (Φ) to be equal to a first target phase angle (Φ1); and - When the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), the rotation speed of the follower motor (40) is modified (212) by the processing circuit (82) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0102] Example 10: The method according to Example 9 further comprises: - modifying (200) the rotation speed of the follower motor (40) by closing the control loop to adjust the phase angle (Φ) to be equal to the auxiliary target phase angle (Φ1); - when the phase angle is equal to the auxiliary target phase angle, and when the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), modifying (200) the rotation speed of the follower motor (40) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0103] Example 11: The method according to any one of Examples 9 and 10, in addition to modifying (212) the rotation speed of the follower motor (40), further includes: modifying the rotation speed of the lead motor (30) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

[0104] Example 12: The method of any one of Examples 9 to 11, wherein the phase angle (Φ) is determined by a phase locked loop.

[0105] Example 13: The method according to any one of Examples 9 to 12, wherein the rotation speed of the guide motor (30) is equal to the initial rotation speed.

[0106] Example 14: The method according to Example 13, wherein the initial rotation speed is equal to or lower than 240 rpm, preferably lower than 60 rpm.

[0107] Example 15: The method according to any one of Examples 9 to 14, wherein when the main target phase angle (Φ2) is reached, the rotational speeds of the leading motor (30) and the following motor (40) are modified (216) to a final rotational speed.

[0108] Example 16: The method according to Example 15, wherein the final rotation speed is equal to or greater than 1000 rpm, preferably equal to or greater than 4800 rpm.

[0109] Example 17: The method according to any one of Examples 15 or 16 further comprises: controlling the rotation speeds of the leading motor (30) and the following motor (40) to maintain the phase angle (Φ) equal to the main target phase angle (Φ2).

[0110] Example 18: The method according to any one of Examples 15 to 17 further comprises: controlling the rotation speed of the leading motor (30) and / or the following motor (40) to maintain the final rotation speed.

[0111] Example 19: A computer program product (94) comprising program code for performing the method of any of Examples 9 to 18 when executed by a processing circuit (82).

[0112] Example 20: A non-transitory computer-readable storage medium (94) comprising instructions that, when executed by a processing circuit (82), cause the processing circuit (82) to perform the method of any of Examples 9 to 18.

[0113] The terms used herein are only used for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more associated listed items. It will be further understood that the terms "comprises", "comprising", "includes" and / or "including" when used herein indicate the presence of stated features, wholes, actions, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, actions, steps, operations, elements, parts and / or their groups.

[0114] It should be understood that although the terms "first", "second", etc. may be used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0115] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element as shown in the figures. It should be understood that these terms and those discussed above are intended to cover different orientations of the device in addition to the orientation depicted in the figures. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there can be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0116] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. It should also be understood that the terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art, and, unless explicitly defined as such herein, should not be interpreted in an idealized or overly formal sense.

[0117] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; on the contrary, those skilled in the art will recognize that many modifications and variations are possible within the scope of the present disclosure and the appended claims. In the drawings and the specification, various aspects have been disclosed for the purpose of illustration only and not for the purpose of limitation, and the scope of the present disclosure is set forth in the appended claims.

Claims

1. A computer system (80) for detecting and controlling the relative position of two rotating eccentric shafts (50, 60), the computer system (80) comprising a processing circuit (82), the processing circuit (82) being configured to: Calculate the guide motor quadrature current (I) of the guide motor (30) driving the first eccentric shaft (50) of the two eccentric shafts (50, 60) q1 ); Calculate the follower motor quadrature current (I) of the follower motor (40) driving the second eccentric shaft (60) of the two eccentric shafts (50, 60) q2 ); Determine the guide motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) between the phase angle (Φ); Modifying the rotation speed of the follower motor (40) by closed-loop control so that the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30); and When the rotation speed of the following motor (40) is equal to the rotation speed of the leading motor (30), the rotation speed of the following motor (40) is modified to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

2. The computer system (80) of claim 1, wherein: The processing circuit (82) is further configured to: Modifying the rotation speed of the follower motor (40) by closing the control loop to adjust the phase angle (Φ) to be equal to the auxiliary target phase angle (Φ1); and When the phase angle (Φ) is equal to the auxiliary target phase angle (Φ1) and when the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), the rotation speed of the follower motor (40) is modified to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

3. The computer system (80) according to any one of claims 1 and 2, wherein: The processing circuit (82) is further configured to: In addition to modifying the rotation speed of the follower motor (40), the rotation speed of the lead motor (30) is also modified to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

4. The computer system (80) according to any one of claims 1 and 2, wherein: The processing circuit (82) is further configured to: when the phase angle (Φ) is equal to the main target phase angle (Φ2), control the rotation speed of the leading motor (30) and / or the following motor (40) to maintain the phase angle (Φ) equal to the main target phase angle (Φ2).

5. The computer system (80) according to any one of claims 1 and 2, wherein: The processing circuit (82) is configured to determine the guide motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) is the phase angle (Φ) between them.

6. A vehicle (1) comprising the computer system (80) according to any one of claims 1 to 5.

7. The vehicle (1) according to claim 6, further comprising: a leading motor (30) and a following motor (40); and A first roller (10) and a second roller (20), wherein the first roller (10) includes a first eccentric shaft (50), and the second roller (20) includes a second eccentric shaft (60), the first eccentric shaft (50) is connected to the guide motor (30), the guide motor (30) is configured to drive the first eccentric shaft (50), and the second eccentric shaft (60) is connected to the follower motor (40), and the follower motor (40) is configured to drive the second eccentric shaft (60).

8. The vehicle (1) according to any one of claims 6 and 7, wherein: At least one of the leading motor (30) and the following motor (40) is a brushless DC motor.

9. A computer-implemented method for detecting and controlling the relative position of two rotating eccentric shafts (50, 60), the method comprising: The processing circuit (82) of the computer system (80) calculates (204) the pilot motor quadrature current (I q1 ), the guide motor (30) drives the first eccentric shaft (50) of the two eccentric shafts (50, 60); The processing circuit (82) calculates (206) a follower motor quadrature current (I q2 ), the follower motor (40) drives the second eccentric shaft (60) of the two eccentric shafts (50, 60); The processing circuit (82) determines (208) the pilot motor quadrature current (I q1 ) and the follower motor quadrature current (I q2 ) between the phase angle (Φ); By means of a closed loop control included in the processing circuit (82), the rotation speed of the follower motor (40) is modified (200) to be equal to the rotation speed of the lead motor (30); and When the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), the processing circuit (82) modifies (212) the rotation speed of the follower motor (40) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

10. The method according to claim 9, further comprising: Modifying (200) the rotation speed of the follower motor (40) by closing the control loop to adjust the phase angle (Φ) to be equal to the auxiliary target phase angle (Φ1); When the phase angle is equal to the auxiliary target phase angle and the rotation speed of the follower motor (40) is equal to the rotation speed of the lead motor (30), the rotation speed of the follower motor (40) is modified (200) to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

11. The method according to any one of claims 9 and 10, further comprising: In addition to modifying (212) the rotational speed of the follower motor (40), the rotational speed of the lead motor (30) is also modified to adjust the phase angle (Φ) to be equal to the main target phase angle (Φ2).

12. The method according to any one of claims 9 and 10, wherein: The phase angle (Φ) is determined by a phase locked loop.

13. The method according to any one of claims 9 and 10, wherein: The rotation speed of the guide motor (30) is equal to the initial rotation speed.

14. A non-transitory computer-readable storage medium (94) comprising instructions that, when executed by a processing circuit (82), cause the processing circuit (82) to perform the method of any one of claims 9 to 13.

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