Regulation of electric machine having two separate winding systems and operation of actuators of corresponding regulation system and steering-by-wire system
By sending status information between adjustment devices, the torque conflict problem caused by adjustment characteristics deviation in the motor of the separate winding system is solved, and the usability of the motor and the stability of the system are improved.
Patent Information
- Application Number
- CN202380075370.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-10-27
- Filing Date
- 2023-08-30
- Publication Date
- 2025-06-06
AI Technical Summary
In a motor with a separate winding system, the deviation of the adjustment characteristics of the adjustment device leads to a torque collision, affecting the adjustment stability of the motor, and thus preventing the system from working normally.
By sending status information at preset time intervals between the adjustment devices, the adjustment device can obtain status information of other adjustment devices, adapt to their operating characteristics, identify failed or restricted states, and adjust the operating characteristics to avoid torque conflicts.
Improves motor availability, avoids torque conflicts, ensures that the system can still operate safely in partial failures, and provides redundant communication paths to avoid single point of failure.
Smart Images
Figure CN120113148A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a method for adjusting the position of a rotor of an electric machine having at least two separate winding systems and a corresponding device. The invention also relates to a method for operating an actuator, in particular a feedback actuator or a steering actuator, of a steer-by-wire system, which actuator comprises an electric machine having at least two separate winding systems. Background Art
[0002] Electric machines with separate winding systems are typically used in applications with particularly high demands on operational safety and availability, such as steer-by-wire systems for motor vehicles. Such steer-by-wire systems are steering systems with electric actuators to which steering commands are transmitted exclusively electronically.
[0003] In order to control an electric machine with separate winding systems, it is known from the doctoral thesis “JW Bennett. Fault-Tolerant Electromechanical Actuators for Aircraft. PhD Thesis. Newcastle University, 2010” to regulate each winding system in the winding system by means of a regulating device associated with the respective winding system. The regulating device comprises an inner current regulating loop for regulating the current of the electric machine, an intermediate speed regulating loop upstream of the inner current regulating loop for regulating the speed of the electric machine, and an outer position regulating loop upstream of the intermediate speed regulating loop for regulating the position of the rotor of the electric machine or the position of an actuator element coupled to the rotor.
[0004] In such electric motors, in which two winding systems drive the same mechanical axle, relatively large differences in the torques and set currents acting on the common axle typically occur even in the case of small deviations in the control characteristics of the two control devices. This can result in interacting torques (so-called "torque fighting"), which negatively influence the control stability of the electric motor, so that the overall system can no longer function properly. To remedy this, the aforementioned doctoral thesis proposes a continuous balancing of the two control devices, in which the outputs of the regulators of the corresponding speed control loops are added. The sum is halved and supplied to the current control loops of the two control devices. Summary of the invention
[0005] Against this background, the object is to achieve greater availability of an electric machine having a separate winding system and an associated regulating device.
[0006] The object is achieved by a method for adjusting the position of a rotor of an electric machine having at least two separate winding systems, wherein each of the winding systems is adjusted by a regulating device associated with the respective winding system, wherein each of the regulating devices sends status information at preset time intervals, the status information indicating the state of the regulating device sending the status information.
[0007] In the method according to the invention, the regulating device sends the following status information, which does not contain measured values, control variables or adjustment variables, but rather relates to the state of the regulating device that is sending, in particular the operating state. It is thus possible that the regulating device obtains knowledge about the state of a corresponding plurality of other regulating devices and adapts its own operating characteristics to this. Optionally, the measured values, control variables or adjustment variables can be additionally replaced. For example, it is thus possible to identify the failure of one of the remaining regulating devices and the remaining regulating devices can change their operating characteristics so that the failure of the first-mentioned regulating device is at least partially compensated. It is also possible to identify the failure of the status information and the remaining regulating devices change their operating characteristics so that a safe operating state with limited performance is occupied. For example, the regulating device can reduce or even terminate the synchronization of the measured values, control variables or adjustment variables when there is no status information. As a result, although the ability to prevent "torque conflicts" is limited, the regulating devices can control the corresponding winding systems independently of each other.
[0008] Within the scope of the present invention, the position of the rotor is preferably understood to be the angular position of the rotor. The position or angular position of the rotor can be specified, for example, relative to a zero position of the rotor, for example by an angle relative to the zero position.
[0009] Preferably, exactly two separate winding systems and exactly two adjusting devices are provided.
[0010] According to an advantageous design of the present invention, the status information includes one or more descriptions in the following list:
[0011] - Indicates whether the respective regulating device is operated with a limited voltage supply or with an unlimited voltage supply;
[0012] - Indicates whether the respective regulating device actively controls the respective winding system connected thereto;
[0013] - indicates whether the switch-off trigger of the corresponding regulating device is activated.
[0014] The mentioned description can be determined by the determination device of the corresponding regulating device in a determination step before the state information is sent. Preferably, the description is stored in a state register of the regulating device. The description stored in the state register can then be read and sent by the sending device of the corresponding regulating device.
[0015] According to an advantageous embodiment of the invention, it is provided that the status information is sent via a communication channel, via which the status information can be received by a further control device or a plurality of further control devices. The communication channel can be designed, for example, as a communication bus, for example a CAN bus.
[0016] According to an advantageous embodiment of the present invention, the further control device or the further control devices check whether the status information is received at a preset time interval. The further control device can have a receiver or a listener, which checks the orderly reception of the status information at a preset time interval.
[0017] According to an advantageous embodiment of the invention, it is proposed that if the check shows that the status information is no longer received at the preset time interval, the control device that has performed the check queries the status register of the control device that previously sent the status information. By means of this query, it can be determined whether an error state exists in the previously sending control device or whether an error exists when sending the status information. The status register is preferably designed as part of the sending control device. The query of the status register is preferably carried out via a communication path different from the sending of the status information, so that a redundant communication path is provided.
[0018] For example, it can be provided that the status register is queried by means of communication via a unit located superordinately to the regulating device. The superordinate unit can provide a communication path that is different from the communication path for transmitting status information between the regulating devices.
[0019] Alternatively, the status register can be queried via another communication bus or via a direct signal connection, in particular a direct digital signal connection, between the regulating devices.
[0020] According to an advantageous embodiment of the invention, if the check shows that the status information is no longer received at the predefined time interval, the control device that has performed the check queries whether the power electronics of the control device that previously sent the status information are disconnected from the winding system associated therewith. The information can be provided either by the control device that previously sent or by a system located upstream of the control device.
[0021] According to an advantageous design of the present invention, if the test shows that the state information is no longer received at the preset time interval, the regulating device that has performed the test is changed from the synchronous operating state to the asynchronous operating state, in which the measured values, controlled variables or regulated variables of one or more other regulating devices are used, and in which the measured values, controlled variables or regulated variables of other regulating devices are not used. In the synchronous operating state, "torque conflicts" can be prevented particularly well due to the replacement of measured values, controlled variables or regulated variables. The asynchronous operating state provides an operating state with limited performance, which however enables the continued operation of the motor or the system.
[0022] Another subject matter of the invention is a method for operating an actuator, in particular a feedback actuator or a steering actuator, of a steer-by-wire system, which actuator comprises an electric machine having at least two separate winding systems, wherein the position of a rotor of the electric machine is set according to the method.
[0023] In the method for operating an actuator, the same advantages as those already described in conjunction with the method according to the invention for adjusting the position of a rotor of an electric machine having at least two separate winding systems can be achieved.
[0024] According to an advantageous embodiment of the present invention, the electric motor is a permanently excited synchronous motor or a reluctance motor.
[0025] Another subject of the present invention is a device for adjusting the position of a rotor of an electric machine having at least two separate winding systems, wherein each of the winding systems can be adjusted by a regulating device associated with the respective winding system, wherein each of the regulating devices is configured to send status information at preset time intervals, the status information indicating the state of the regulating device sending the status information.
[0026] The same advantages as those described in connection with the method for adjusting the position of the rotor of an electric machine having two separate winding systems can be achieved in the device for adjusting the position. The advantageous embodiments and features described above can also be applied in the method for operating an actuator and in the device for adjusting the position. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Further details and advantages of the invention are explained below with reference to the exemplary embodiment shown in the drawing.
[0028] Here it is shown:
[0029] Figure 1 A first embodiment of a steer-by-wire system having an actuator including two separate winding systems is shown;
[0030] Figure 2 A second embodiment of a steer-by-wire system is shown having an actuator including two separate winding systems; and
[0031] Figure 3 A communication diagram showing an embodiment of a device for adjusting the position of a rotor according to the invention. DETAILED DESCRIPTION
[0032] exist Figure 1 , a steer-by-wire system 1 is shown in which the present invention can be used. The steer-by-wire system 1 is designed as a supplementary system for a steering system 2, which is a steering system 2 with a servo-steering device 3. The steer-by-wire system 1 comprises an actuator 5 arranged on a steering column 4 of the steering system 2, which actuator has an electric motor 6. The actuator 5 can be designed as a steering actuator or a feedback actuator. The electric motor 6 comprises a plurality of separate winding systems, here precisely two separate winding systems, which can be controlled independently of one another.
[0033] The steer-by-wire system 1 also comprises a device 10 according to the invention for adjusting the position of the rotor of the electric motor 6. The device 10 is configured to control the separate winding systems of the electric motor 6. To this end, the device 10 comprises a plurality of adjusting devices 11, wherein each winding system is respectively associated with one of the adjusting devices 11.
[0034] Figure 2 A further embodiment of a steer-by-wire system 1 is shown, in which the present invention can be used. The steer-by-wire system 1 according to the second embodiment is designed as a steering system for an axle of a vehicle, for example a front axle steering system or a rear axle steering system. The steer-by-wire system 1 comprises a steering actuator 5 coupled to a lever 7, which has an electric motor 6. The electric motor 6 comprises a plurality of separate winding systems, here precisely two separate winding systems, which can be controlled independently of one another.
[0035] In the steer-by-wire system 1 according to the second embodiment, the device 10 according to the invention for adjusting the position of the rotor of the electric motor 6 can also be used. The device 10 is configured to control the separate winding systems of the electric motor 6. To this end, the device 10 comprises a plurality of adjusting devices 11, wherein each winding system is respectively associated with one of the adjusting devices 11.
[0036] Figure 3 The communication diagram shows a first exemplary embodiment of a device 10 for adjusting the position of a rotor of an electric machine 6. The electric machine comprises two winding systems which are designed separately from one another. The winding systems act on a common shaft or a common rotor, whose position or angular position is to be adjusted.
[0037] For this purpose, the device 10 is respectively pre-set with a position target value, which is fed to two control devices 11 designed as cascade control. The control devices 11 are designed identically. Each of the control devices 11 is associated with one of the two winding systems of the electric machine 6. The control devices 11 can, for example, have a three-stage structure with an inner current control loop, a middle speed control loop and an outer position control loop. However, structures different from this are also conceivable.
[0038] According to the invention, the control device 11 is configured to send status information 12, 13 at preset time intervals, which state information describes the state of the control device 11 that sends the status information. The status information 12, 13 is sent via a communication channel, via which the status information 12, 13 can be received by the respective other control device 11. The other control devices 11 each include a receiver, which checks whether the status information 12, 13 is received at preset time intervals.
[0039] If the check shows that the status information 12, 13 is no longer received at the predefined time interval, the control device 11 that has performed the check can take appropriate measures. For example, the status register of the control device 11 that previously sent the status information can be queried. Alternatively or additionally, it can be queried whether the power electronics of the control device 11 that previously sent the status information are disconnected from the winding system associated therewith. This query can be carried out via a unit located upstream of the control device 11, that is, via a different communication path than the one used to send the status information 12, 13.
[0040] By means of the method according to the invention, a safety monitoring design is provided that complies with ASIL-D and ISO 26262 and does not have a "single point of failure". Actual redundancy is provided from the sensor mechanism to the actuator. In particular, the provision of different information on different paths shows redundancy, so that in the event of a fault in one communication path, information about the normal operation of the regulating device can still be determined via another communication path. For example, in the event of a failure of a communication bus, such as a CAN bus, it is still possible to verify whether the regulating device is functional by querying whether the power electronics of the regulating device 11 that has previously sent status information and the winding system associated therewith are separated (so-called phase cutoff). Therefore, the communication between the regulating devices 11 also does not contain a "single point of failure".
[0041] Furthermore, the diversity in the communicated information also allows the detection of situations in which the control devices 11 are operating completely correctly, although the communication between the control devices 11 is disrupted. The first control device 11 will also increase the generated torque to the maximum power without communication. In this case, it is not the mechanical power provided by the system that is involved, but rather the control device 11 that adjusts its own characteristics based on its environmental diagnosis. This can, for example, mean that the controller of the control device 11 deactivates the I share in order to prevent a "torque fight" when synchronization is no longer possible.
[0042] Unlike the above-described embodiment, the rotor of the electric machine can be coupled to the actuator element, for example via a transmission. In this case, the method according to the invention directly adjusts the position of the actuator element and indirectly adjusts the position of the rotor of the electric machine.
[0043] The device 10 described above and the method implemented therewith for adjusting the position of the rotor of an electric machine 6 having two separate winding systems can be used for operating actuators of a steer-by-wire system. In particular, feedback actuators or steering actuators of such steer-by-wire systems can be adjusted. The invention achieves greater usability of steer-by-wire systems.
Claims
1. A method for adjusting the position of a rotor of an electric machine (6) having at least two separate winding systems, wherein each of the winding systems is adjusted by a regulating device (11) associated with the respective winding system, wherein each of the regulating devices (11) sends status information (12, 13) at preset time intervals, the status information indicating the status of the regulating device (11) sending the status information.
2. The method according to claim 1, It is characterized in that The status information (12, 13) includes one or more descriptions from the following list: - indicating whether the corresponding regulating device (11) is operated with a limited voltage supply or with an unlimited voltage supply; - indicating whether the corresponding regulating device (11) actively controls the corresponding winding system connected thereto; - indicates whether the switch-off trigger of the corresponding regulating device (11) is activated.
3. The method according to any one of the preceding claims, It is characterized in that The state information is transmitted via a communication channel, via which the state information (12, 13) can be received by a further control device (11) or a plurality of further control devices (11).
4. The method according to claim 3, It is characterized in that The further control device (11) checks or the further control devices (11) checks whether the status information (12, 13) is received at the predefined time intervals.
5. The method according to claim 4, It is characterized in that If the check shows that the status information (12, 13) is no longer received at the predetermined time interval, the regulating device (11) that has performed the check queries the status register of the regulating device (11) that previously sent the status information (12, 13).
6. The method according to claim 5, It is characterized in that The status register is queried by means of communication via a unit located upstream of the regulating device (11), or via another communication bus or via a direct signal connection, in particular a direct digital signal connection, between the regulating devices (11).
7. The method according to any one of claims 4 to 6, It is characterized in that If the check shows that the status information (12, 13) is no longer received at the preset time interval, the control device (11) that has performed the check queries whether the power electronics of the control device (11) that has previously sent the status information (12, 13) are disconnected from the winding system associated therewith.
8. The method according to any one of claims 4 to 7, It is characterized in that If the check shows that the status information (12, 13) is no longer received at the preset time interval, the control device (11) that has performed the check changes from a synchronous operating state to an asynchronous operating state, in which the measured values, controlled variables or controlled variables of one or more other control devices (11) are used, and in which the measured values, controlled variables or controlled variables of the other control devices (11) are not used.
9. A method for operating an actuator (5), in particular a feedback actuator or a steering actuator, of a steer-by-wire system, the actuator comprising an electric motor (6) having at least two separate winding systems, wherein the position of the rotor of the electric motor (6) is set according to a method according to any of the preceding claims.
10. The method according to claim 9, It is characterized in that The motor (6) is a permanently excited synchronous motor or a reluctance motor.
11. A device for adjusting the position of a rotor of an electric machine (6) having at least two separate winding systems, wherein each of the winding systems can be adjusted by a regulating device (11) associated with the corresponding winding system, wherein each of the regulating devices (11) is configured to send status information (12, 13) at preset time intervals, wherein the status information describes the status of the regulating device (11) that sends the status information (12, 13).