Method and apparatus for operating an actuator and system with an actuator

Abstract

The subject of the invention is a method and a device for operating an actuator and a system with an actuator. A method and a device for operating an actuator and a system with at least one actuator are disclosed. The disclosed device for operating an actuator with a belt drive comprises an interface circuit communicatively coupled with a first sensor and a second sensor, machine readable instructions, and at least one programmable circuit; the programmable circuit is configured to cause a specified torque to be applied to a motor shaft of the belt drive, determine a first angle of rotation of the motor shaft based on a first output signal of the first sensor, determine a second angle of rotation of an output shaft of the belt drive based on a second output signal of the second sensor, determine a reaction time of the output shaft based on the torque applied to the motor shaft, the first angle of rotation, and the second angle of rotation, estimate a tension of a toothed belt coupling the output shaft to the motor shaft based on the determined reaction time, and adjust operation of the actuator in accordance with the tension.

Description

[0001] This patent claims priority to DE patent application number 102025115605.0, filed on April 23, 2025, the entirety of which is incorporated herein by reference. Technical Field

[0002] This disclosure relates to a method and apparatus for operating an actuator, and a system having at least one actuator. Background Technology

[0003] Steer-by-wire (SBW) is a further development of the EPAS steering system (“Electric Power Steering”). While the EPAS steering system relies on mechanical coupling to directly transmit the driver’s steering input to the steerable road wheels, the SBW steering system does not have a direct mechanical connection. Instead, the SBW steering system has two actuator subsystems to ensure lateral guidance and feedback about the vehicle, including the steering wheel actuator (hereinafter referred to as the “feedback actuator”, or FBA) and the road wheel actuator (RWA). The FBA generates feedback torque. The driver’s steering input is detected and transmitted to the RWA so that torque can be output according to the steering input to adjust the orientation of the steerable road wheels. Summary of the Invention

[0004] An exemplary device for operating an actuator with a belt drive includes: an interface circuit communicatively coupled to a first sensor and a second sensor; machine-readable instructions; and at least one programmable circuitry for applying a specified torque to a belt-driven motor shaft, determining a first rotation angle of the motor shaft based on a first output signal from the first sensor, determining a second rotation angle of an output shaft of the belt drive based on a second output signal from the second sensor, determining a response time of the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle, estimating the tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time, and adjusting the operation of the actuator based on the tension.

[0005] An exemplary method includes the following steps: applying a specified torque to a belt-driven motor shaft of an actuator; determining a first rotation angle of the motor shaft based on a first output signal from a first sensor; determining a second rotation angle of an output shaft of the belt drive based on a second output signal from a second sensor; determining a response time of the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle; estimating the belt tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time; and adjusting the operation of the actuator according to the estimated tension.

[0006] An exemplary non-transitory machine-readable storage medium includes instructions to cause programmable circuitry to perform at least the following operations: applying a specified torque to a belt-driven motor shaft; determining a first rotation angle of the motor shaft based on a first output signal from a first sensor; determining a second rotation angle of an output shaft of the belt drive based on a second output signal from a second sensor; determining a response time of the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle; estimating the belt tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time; and adjusting the operation of an actuator according to the tension. Attached Figure Description

[0007] The invention and its further advantageous embodiments and developments are explained and described in more detail below with reference to the examples shown in the figures. In the figures: Figure 1 A schematic diagram of a vehicle having a steering system based on an example disclosed herein is shown.

[0008] Figure 2 A schematic diagram of a belt drive system based on the example disclosed herein is shown.

[0009] Figure 3 Another schematic diagram of a belt drive system based on the example disclosed herein is shown.

[0010] Figure 4 A schematic diagram of a method for operating an actuator with a belt drive, based on an example disclosed herein, is shown.

[0011] Figure 5 This is a block diagram of an exemplary processing platform including programmable circuitry configured to implement, instantiate, and / or execute exemplary machine-readable instructions and / or perform... Figure 4 Exemplary operations are used to implement the electronic steering system and components disclosed in this disclosure. Detailed Implementation

[0012] Steer-by-wire (SBW) systems use an actuator subsystem to ensure lateral guidance and feedback about the vehicle. Actuators include the steering wheel actuator (hereinafter referred to as the "feedback actuator," FBA) and the road wheel actuator (RWA). A failure in these or other actuators may cause them to no longer be able to output torque from the corresponding actuator's electric motor, meaning the orientation of the steering wheel or steerable road wheels can no longer be affected.

[0013] Typically, various types of drives, such as planetary drives, rack and pinion drives, and worm gear drives, can be used in actuators. However, belt drives with toothed belts are commonly used in such actuators because they generally offer low friction, low wear, and high operating efficiency. In contrast, V-belt drives, for example, are rarely used in steering systems because the lack of teeth on the pulleys requires a great deal of effort to reliably prevent belt slippage.

[0014] To ensure the advantages of belt drives, belt tension must be adjusted and maintained within a specific parameter range. If the belt tension drops too much, the likelihood of belt skipping increases. If the belt slips, the position between the two shafts of the belt drive will unintentionally change, thus preventing the proper transmission of torque.

[0015] Belt tension is typically measured indirectly during the installation of a belt drive. For example, this measurement is performed by exciting the belt and recording the frequency profile generated by the excitement. The belt tension can be estimated from the frequency profile. Another typical method is based on applying force to the belt and measuring its translation. Yet another method involves rotating the shaft in a controlled manner and measuring the torque required for rotation. The required torque corresponds to the frictional force of the belt drive, from which the belt tension can be estimated. The frictional force of the belt drive can also be contributed by, for example, bearings in an arrangement (shaft) and an electric motor (through its inertia). Since other contributions to the belt drive's frictional force are known or otherwise estimable, the frictional force of the belt drive itself and its belt tension can be estimated. All these methods rely on using external measuring equipment to record various parameters, meaning they do not allow for estimation of belt tension during normal operation of the actuator and / or under its typical installation conditions.

[0016] If the FBA slips, the driver will receive "incorrect" feedback torque that does not correspond to the corresponding wheel angle of the steerable road wheels, or they will receive no feedback torque at all. As a result, the driver will find it difficult to set the desired steering angle. Normally, the road wheel angle can be controlled based on the steering wheel angle or the motor angle of the FBA's electric motor, which correspond to each other. However, due to FBA slippage, the motor angle no longer corresponds to the steering wheel angle, which can also lead to control errors according to the design of the SBW steering system.

[0017] JP 2015-33951 A discloses a method for measuring belt tension in a steering system and a method for adjusting belt tension. The belt tension is checked based on a load applied when a probe is pressed against the belt surface and a constant deflection is applied to the belt. With the probe pressed against the belt surface, the steering wheel moves throughout its entire rotation range, causing the belt to move. The center distance between the drive pulley and the driven pulley is adjusted so that the maximum and minimum values ​​of the measured load fall within a specified allowable range.

[0018] KR 2023-0151272 discloses an electric power steering system for a vehicle and a method for monitoring belt tension. The electric power steering system includes a drive element comprising a motor controlled by an electronic control unit and a motor pulley coupled to a motor shaft. A strain gauge for measuring belt tension is attached to a motor surface adjacent to the motor shaft.

[0019] The problem to be solved can be viewed as providing an actuator with belt drive and its operating method, which, compared with the past, can determine the belt tension of the actuator more accurately during the operation of the actuator and in its installed condition with less effort.

[0020] This problem is addressed by the examples disclosed herein. Advantageous examples are indicated in the following description, wherein each example may represent an aspect of the invention individually or in (sub)combinations.

[0021] According to the example disclosed here, this objective is also achieved by a method for operating an actuator with a belt drive. The belt drive has a motor shaft at least indirectly coupled to a second shaft. The motor shaft and the output shaft of the belt drive are coupled to each other via a toothed belt. The method includes the following steps: - Apply a specified torque to the motor shaft.

[0022] - The first rotation angle of the motor shaft is detected by the first sensor.

[0023] - The second rotation angle of the second shaft or the output shaft of the belt drive is detected by the second sensor.

[0024] as well as: The response time of the second shaft or output shaft is determined by the evaluation equipment based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle.

[0025] - The belt tension of the toothed belt is estimated by the evaluation equipment based on the determined reaction time and system parameters.

[0026] or: - The belt tension of the toothed belt is estimated by the evaluation equipment based on the applied torque, the first rotation angle, the second rotation angle, and additional system variables.

[0027] The exemplary method above is based on the understanding that if the rotational angle of the corresponding shaft of the belt drive, or at least the shaft indirectly coupled to the belt drive, is recorded during operation, then belt tension can be estimated during operation even without external measuring equipment. Due to the elasticity of the belt, a change in the speed of the motor shaft will only cause a corresponding change in the speed of the second or output shaft after a certain delay, which itself manifests as the reaction time. This elasticity depends particularly on the belt tension of the toothed belt. Based on the reaction time, or alternatively based on the rotational angle and the corresponding system variables, the timing characteristics of the timing belt in the belt drive are determined. This makes it possible to estimate belt tension.

[0028] This enables a method for monitoring belt tension, at least intermittently or even continuously. As a result, manufacturing defects and / or signs of wear can be detected more accurately than before, reducing maintenance costs and, for example, extending maintenance intervals. Furthermore, unwanted operating scenarios, such as timing belt tearing, can be prevented more reliably than ever before. In addition, this method enables additional applications for actuators. For example, some autonomous or semi-autonomous applications require intermittent or continuous monitoring of all involved components, which this method makes possible with respect to belt drives in actuators. Moreover, the estimated belt tension can be used for other functions. For example, the estimated belt tension can be used by a hand detection sensor that detects hand contact based on the torque applied to the shaft.

[0029] System parameters can involve the basic properties of the actuator, such as the moment of inertia of the mass of the component actuated by the actuator, such as the steering column with the steering wheel, or the pinion or recirculating ball gear coupled to the rack and indirectly coupled to the steerable wheel.

[0030] Additional system variables may include, for example: the torque gradient of the applied torque, the first rotational angle gradient of the first rotational angle, the second rotational angle gradient of the second rotational angle, the angular velocity variation of the motor shaft, the angular velocity variation of the second shaft, and the angular velocity variation of the output shaft. Which system variables depend on the specific system design is considered. This means that the method has high variability.

[0031] Preferably, the second shaft is at least indirectly coupled to the output shaft of the belt drive. However, the mechanical coupling between the output shaft and the second shaft may include at least one additional component arranged in the force path between the output shaft and the second shaft. Nevertheless, the second shaft is coupled to the output shaft in such a way that actuation of the output shaft by a torque acting on the motor shaft of the belt drive immediately causes the second shaft to rotate. For example, the second shaft may be a shaft equipped with a pinion, or it may be a shaft with a recirculating ball gear that indirectly transmits the torque applied by the actuator to a component such as a steerable road wheel.

[0032] Optionally, after a specified time interval following the application of torque to the motor shaft, a reverse torque is applied to the motor shaft. The reverse torque is in the opposite direction to the torque. The reverse torque allows for more accurate estimation of belt tension because, for example, the elasticity and backlash of the belt drive in different rotational directions can be taken into account. Furthermore, the reverse torque can bring the belt drive and its coupled components (e.g., a steering wheel) to a stop. Additionally, the component can return to its starting position before further movement.

[0033] The evaluation device preferably determines additional system variables based on the applied torque, a first rotation angle, and a second rotation angle. For example, the evaluation device determines a torque gradient based on the applied torque, a first rotation angle gradient based on the first rotation angle, and a second rotation angle gradient based on the second rotation angle. For this purpose, the evaluation device may have, for example, a differentiating element. Detecting and evaluating different gradients allows for detailed analysis of the dynamic state of the belt drive. This allows for more effective detection of irregularities.

[0034] According to one example, if a second rotation angle is detected for a second shaft, the evaluation device can take into account the elasticity and friction of the output shaft and components arranged in the force path between the output and second shafts, or components that affect the force transmission between the output and second shafts. Including these additional system parameters makes the model significantly more accurate, especially if the second rotation angle is detected for another shaft indirectly coupled to the output shaft of the belt drive, rather than the output shaft itself. For example, the rotation angle can be measured for a pinion or ball screw drive that is only indirectly coupled to the belt drive. This is advantageous due to installation space constraints or because the rotation angle of the pinion or ball screw drive is recorded to estimate other system parameters. In this case, the elasticity and friction of the output shaft, the pinion or ball screw drive, and components arranged between the pinion or ball screw drive and the output shaft can be taken into account. Furthermore, the elasticity and friction of components that affect the force transmission can be taken into account, such as tensioning devices used to adjust the belt tension of toothed belts.

[0035] In one respect, the torque can be a specified test torque or a torque specified during the operation of the actuator. The flexibility offered by using either test or operating torque allows this method to be seamlessly integrated into existing operating and control routines without requiring separate test cycles. Furthermore, the test torque can be used to ensure specific loads, meaning that system parameters determined or estimated during this process can be reliably compared, for example, with parameters obtained from repeated runs of the process.

[0036] The evaluation equipment also preferably estimates belt drive friction based on the applied torque, a first rotation angle, a second rotation angle, and additional system variables. This additional friction estimate allows for a more accurate characterization of the system and all involved components. This results in improved efficiency in estimating necessary maintenance and greater accuracy in additional functions that take friction values ​​into account, such as hand detection sensors.

[0037] Optionally, the evaluation device has an evaluation frequency below a specified frequency threshold. For this purpose, the evaluation frequency can, for example, accommodate a relatively long integration time. As a result, high-frequency abrupt interference can be attenuated, making its impact on the determined and estimated parameters lower. Furthermore, the defined lower evaluation frequency prevents overloading the evaluation hardware, thereby improving energy efficiency.

[0038] Preferably, the evaluation device may have a low-pass filter to ensure an evaluation frequency below a specified frequency threshold.

[0039] In one respect, the torque applied for a given test interval can be variable, and can exhibit amplitude and / or frequency variations within the test interval. Variations in torque generate a more extensive database of the dynamic behavior of the belt drive. This allows for the recording of different operating points, thereby further improving the accuracy of the method. For example, frequency variations can be used to excite the system's natural frequency. Since the system's natural frequency depends on the system's elasticity, the system's elasticity can be estimated in this way.

[0040] In some examples, the specifyable torque is applied only at the beginning or end of a driving cycle. This is advantageous if the specifyable torque is a test torque, because at these points in time, other components coupled to the actuator are not yet or no longer used for normal operation. In other words, this design can effectively utilize system states that have already occurred, such as start-up or shutdown processes. This reduces the impact on continuous operation, thereby improving comfort and reducing the effort required for the process.

[0041] Optionally, the specified torque is applied only when the driver is not applying any torque to the steering wheel, which is at least indirectly coupled to the actuators, and / or when the driver is not inside the vehicle. This is advantageous if the specified torque is a test torque. This means that the vehicle's steering is less affected, resulting in greater driver comfort. Furthermore, it ensures consistent steering behavior, thus preventing any impairment to the driving experience. In other words, the process then occurs autonomously and unnoticed by the driver.

[0042] If the estimated belt tension is less than a specified tension threshold, the evaluation device preferably outputs a notification. For example, the notification can be output to a user interface.

[0043] Alternatively or additionally, in some examples, if the estimated belt tension is less than a specified tension threshold, the evaluation device may result in power limitations on the actuator and / or external components coupled to the actuator, such as limitations on the maximum output motor torque, or limitations on the maximum vehicle speed or the maximum requestable speed or speed variation of the steerable road wheel, for example, power limitations based on the torque output of the RWA.

[0044] This informs the driver that the belt tension is too low, allowing them to adjust the use of the actuator and / or its arrangement for maintenance purposes. Power limiting prevents improper operation of the system, allowing the actuator to remain usable for a certain period, albeit with reduced performance. Both measures improve operational reliability.

[0045] Optionally, the estimated belt tension must be less than a specified tension threshold for a specified time period before a notification and / or power limiting will take effect. This prevents isolated elastic conditions from causing anomalies that immediately trigger one of the aforementioned measures.

[0046] In some examples, the evaluation device is able to consider different specified tension thresholds for power limiting and notifications. This fine-grained distinction between notifications and proactive system interventions based on power limiting allows for customized coordination of the evaluation device's behavior according to tension deviations of varying severity with respect to the at least one specified tension threshold. This improves reliability and user acceptability.

[0047] According to another aspect, the examples disclosed herein also relate to a computer program product containing instructions that, when executed by a processor, cause the processor to perform at least partially the previously described methods, particularly the output and computation steps. The advantages achieved by the methods described herein are also realized by this computer program product.

[0048] According to yet another aspect, the examples disclosed herein also relate to a computer-readable storage medium containing instructions that, when executed by a processor, cause the processor to perform at least partially the previously described methods, particularly the output and computation steps. The advantages achieved by the methods described herein are also correspondingly realized by this computer-readable storage medium.

[0049] According to another aspect, this objective is achieved by a system having at least one actuator, according to an example disclosed herein. The actuator has a belt drive and an electric motor. The system includes a first sensor, a second sensor, and an evaluation device. The evaluation device is at least coupled to a control device of the first sensor, the second sensor, and the actuator. The belt drive has a motor shaft at least indirectly coupled to a second shaft. The motor shaft and the output shaft of the belt drive are coupled to each other via a toothed belt. The electric motor is designed to apply a specifyable torque to the motor shaft of the belt drive according to an adjustment signal from the control device. The first sensor is designed to detect a first rotation angle of the motor shaft. The second sensor is configured to detect a second rotation angle of the second shaft or the output shaft of the belt drive. The evaluation device is configured to: - Determine the response time of the second shaft or output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle, and -Based on the determined reaction time and system parameters, estimate the belt tension of the toothed belt. And / or: - Estimate the timing belt tension based on the applied torque, first rotation angle, second rotation angle, and additional system variables.

[0050] The advantages achieved by this exemplary method are also realized by this system. In particular, a system has been created that enables the estimation of timing belt tension during installation, configuration, and operation without the need for external measuring equipment. This optimizes maintenance requirements. Furthermore, the system achieves higher accuracy and additional applications based on the estimated belt tension.

[0051] Alternatively, the actuator can be a wheel actuator or a steering wheel actuator in the vehicle's steering system. Its use in the vehicle's steering system allows for continuous steering control and error-free operation. Furthermore, wear and tear on the steering system and the corresponding maintenance costs are reduced.

[0052] Preferably, the sensor has high measurement resolution and update rate. Furthermore, the sensor is capable of low latency. This allows for accurate (especially in terms of time) recording of rotation angles.

[0053] In one aspect, power limiting performed by the evaluation equipment may include limiting the vehicle's maximum speed. To this end, the evaluation equipment can output corresponding adjustment signals to external components (such as vehicle control equipment). This ensures that the lateral forces acting on the vehicle are limited.

[0054] Optionally, the evaluation device is coupled to the vehicle's user interface. The evaluation device can then output notifications to the vehicle's driver.

[0055] In some examples, the second sensor is not arranged to detect the rotation angle of the output shaft, but rather preferably arranged relative to the force path from the output shaft to the steering wheel or steerable wheel, such that it detects the rotation angle relative to a component positioned as close as possible to the output shaft. As a result, very few additional components are arranged in the force path between this component and the output shaft. Therefore, the additional effects of other components arranged in the force path between this component and the output shaft are minimal, particularly in terms of friction and elasticity caused by these additional components. This simplifies and makes the estimation of belt tension more accurate, even if the second rotation angle is not measured relative to the output shaft, but rather relative to a component only indirectly coupled to it.

[0056] Preferably, the second sensor can also be designed as a linear rack sensor, as a pinion sensor integrated in a pinion disk rotating around the second axis, or as a transmission sensor for detecting the movement of a component of a recirculating ball gear.

[0057] According to another aspect, this objective is also achieved by a vehicle having a steering system as described above. The advantages achieved by the steering system are also achieved by this vehicle accordingly.

[0058] In the context of this invention, a vehicle can particularly include land vehicles (i.e., especially off-road and on-road vehicles, such as passenger cars, buses, trucks, and other commercial vehicles). Motor vehicles can be manned or unmanned. Vehicles can have an internal combustion engine, or alternatively, an electric motor for propulsion, or can be hybrid vehicles.

[0059] All features mentioned below in the examples and / or figures can be combined with the features of the examples disclosed herein, including the features of preferred examples, individually or in any sub-combination.

[0060] Figure 1 A vehicle 10 with an exemplary steering system 12 is shown. Here, the steering system 12 is designed, for example, as an SBW steering system. The steering system 12 includes a system 14 according to the teachings of this disclosure.

[0061] The steering system 12 includes a steering wheel wing (RWA) 16. The steering system 12 also includes a steering engine ballast (FBA) 18 and a control device 20. The FBA 18 and the RWA 16 are coupled to each other.

[0062] According to this example, the steering system 12 has only a single control device 20. However, in general, the RWA 16 and FBA 18 can each have a separate control device 20 to control their respective actuators.

[0063] According to this example, the RWA 16 is indirectly coupled to the steerable road wheel 22 of the vehicle 10. For this purpose, the RWA 16 according to this example includes an electric motor 24, which is coupled to a belt drive 26. The belt drive 26 is at least indirectly coupled to a rack 28. The RWA 16 is capable of outputting torque via the electric motor 24, which acts on the rack 28 via the belt drive 26. This allows the position of the rack 28 to be changed along the rack path.

[0064] The rack 28 is at least indirectly coupled to the steerable wheel 22 of the vehicle 10. Displacement of the rack 28 relative to a reference position, such as the zero position (directly forward position), causes a change in the orientation of the steerable wheel 22 about the wheel steering axis of the respective wheel 22.

[0065] The steering system 12 has a road wheel angle sensor 30, which is designed to capture the road wheel angle of the steerable road wheel 22 around the corresponding wheel steering axis and transmit it to the control device 20.

[0066] In an alternative example, instead of the wheel angle sensor 30, the SBW steering system 12 may also have a rack sensor 32 that captures the position of the rack 28 relative to a reference position. Since the rack 28 is coupled to the steerable wheel 22, deflection of the rack 28 causes the steerable wheel 22 to rotate about the corresponding wheel steering axis. Therefore, the orientation of the steerable wheel 22 can be determined from the corresponding detected rack position, particularly by the control device 20 of the steering system 12.

[0067] In some examples, instead of the road wheel angle sensor 30, a pinion sensor 34 can also be used, which indicates the position and / or orientation of the pinion, which is at least indirectly coupled to the RWA 16. The pinion is mounted on a shaft and rotates about its axis of rotation according to the torque output by the RWA 16. Since the pinion is also indirectly coupled to the steerable road wheel 22, the orientation and / or position of the pinion can be used to determine the orientation of the steerable road wheel 22.

[0068] In a further alternative example, instead of the wheel angle sensor 30, a sensor that detects the movement of a component driven by a ball screw can also be used. The ball screw drive is used to convert rotary motion into translational motion. The only determining factor is the detection of the movement of a component, which, for example, indirectly corresponds to the movement of the steerable wheel, taking into account a specific gear ratio.

[0069] Of course, multiple sensor units can also work together to form a single sensor, thereby enabling mutual rationality checks and redundancy.

[0070] The steering system 12 also includes a steering wheel 36, to which the FBA 18 is coupled at least indirectly (e.g., via the steering column). The FBA 18 similarly has an electric motor 24. Using the electric motor 24, the FBA 18 can apply torque, which acts on the steering wheel 36 via a belt drive 26 of the FBA 18. This torque affects the steering wheel angle and / or steering wheel speed, for example, based on adjustment signals from the control device 20.

[0071] FBA 18 is specifically designed to apply feedback torque to steering wheel 36 in order to provide the driver of vehicle 10 with a sense of lateral guidance of the vehicle.

[0072] The driver of vehicle 10 can use steering wheel 36 to formulate steering specifications for vehicle 10.

[0073] The steering system 12 also includes at least one steering wheel sensor 38, which is configured to capture the steering wheel angle of the steering wheel 36 relative to a reference position, such as a center position (zero position), i.e., the steering wheel position. Therefore, the steering wheel sensor 38 can be used to capture steering commands from the driver of the vehicle 10 based on the steering wheel 36. In this respect, the specific current steering wheel angle and steering wheel speed are defined by the steering commands.

[0074] According to this example, vehicle 10 also has a HOOD sensor 40, which is indirectly coupled to steering wheel 36 according to the teachings of this disclosure. HOOD sensor 40 includes a torque sensor coupled to the steering column on which steering wheel 36 is mounted. When there is hand contact (i.e., when the driver grips steering wheel 36), the driver applies torque to the steering column, which can be detected by the torque sensor. This allows HOOD sensor 40 to determine that the driver has control of steering wheel 36 based on the driver's contact with steering wheel 36. HOOD sensor 40 then transmits the detected hand contact to control device 20.

[0075] In some examples, the control device 20 itself can also be configured to determine hand contact, for example, based on additional sensor signals, such as internal sensors partially integrated into the steering wheel 36 or capacitance-based sensors, or through estimation algorithms or model-based software functions.

[0076] Even though this describes hand contact, it is obviously possible to detect or determine contact based on other (preferably exposed) parts of the body.

[0077] The current steering specification at steering wheel 36 typically corresponds to a specific current road wheel setting angle, according to which road wheel 22 is aligned and steered. Since road wheel 22 is at least indirectly coupled to rack 28, the steering specification is equivalent to a specific rack position of rack 28, according to which rack 28 is moved to set the desired orientation of road wheel 22. Alternatively, the steering specification corresponds to a specific position and / or orientation of the pinion coupled to RWA 16.

[0078] By changing the steering wheel position, the driver dynamically alters the current steering specification, which in turn causes a dynamic change in the rack position. Furthermore, based on the orientation of the steerable wheel 22 or the rack position of the rack 28, the feedback torque achievable on the steering wheel 36 via FBA 18 is determined. Based on this feedback torque, the driver is given a sense of lateral guidance regarding the vehicle 10.

[0079] In this example, the steering wheel sensor 38 is integrated into the FBA 18. However, in other examples, the steering wheel sensor 38 can be separate from the FBA 18. The steering wheel sensor 38 is configured to transmit the detected steering wheel angle to the control device 20.

[0080] The control device 20 of the steering system 12 is also configured to output corresponding adjustment signals to the electric motor of the RWA 16 or a converter coupled thereto. In order to execute the corresponding control routine, the control device 20 can take into account additional parameters of the vehicle 10, such as vehicle speed.

[0081] To control the orientation of the steerable road wheel 22, the control device 20 outputs an adjustment signal to the electric motor 24 of the RWA 16 or a converter connected to it. Due to this adjustment signal, the electric motor 24 of the RWA 16 provides output torque to align the steerable road wheel 22 accordingly. The output torque from the electric motor 24 of the RWA 16 can also be applied to the rack 28, rather than directly to the road wheel 22, thereby indirectly altering the alignment of the steerable road wheel 22.

[0082] For the various functions associated with FBA 18 and RWA 16, separate partial control devices could also be provided to affect road wheels 22 or apply torque to steering wheel 36, i.e., each individually assigned to FBA 18 or RWA 16. In contrast, only a single common control device 20 for steering system 12 is used here.

[0083] Wheel angle sensor 30 captures the wheel angle of the steerable wheel 22 and transmits the captured wheel angle to control device 20. Control device 20 determines the corresponding feedback torque, taking into account the steering gear ratio, and this feedback torque is output to steering wheel 36. Alternatively, instead of the wheel angle, the rack position of rack 28 can be detected and considered by a corresponding rack sensor, or the pinion orientation coupled to the pinion of RWA 16 can be detected and considered by a pinion sensor.

[0084] According to this example, vehicle 10 includes a driving control device 42. The driving control device 42 is configured to perform autonomous or semi-autonomous driving functions. For example, the driving control device 42 can autonomously influence the lateral guidance of vehicle 10 in this manner. To this end, the driving control device 42 can, for example, specify the steering wheel angle, steering wheel movement, or corresponding parameters, which are then set accordingly by the control device 20 and / or FBA 18 of the steering system 12. The set steering wheel angle is then measured by the steering wheel sensor 38 and transmitted to the control device 20, or directly transmitted by the driving control device 42 to the control device 20 and / or RWA 16. The driving control device 42 also receives measurement data from various sensors, namely the wheel angle sensor 30, the steering wheel sensor 38, and the HOOD sensor 40.

[0085] According to this example, the steering system 12 also includes an evaluation device 44, which is part of the system 14. The evaluation device 44 here is designed as a common evaluation device 44 for both the RWA 16 and FBA 18. However, in general, each actuator, namely the RWA 16 and FBA 18, can also be assigned a separate evaluation device 44.

[0086] The evaluation device 44 is also coupled to the electric motor 24 of RWA 16 and FBA 18, so that the evaluation device 44 knows the torque output of the electric motor 24.

[0087] Typically, the evaluation device 44 is also coupled to sensors configured to detect the rotational angle of a shaft, such as the motor shaft of the corresponding belt drive 26, the output shaft of the corresponding belt drive 26, or a shaft at least indirectly coupled to the corresponding output shaft of the belt drive. For example, this could be a shaft in the force path from RWA 16 to the steerable road wheel 22, such as a shaft with a pinion mounted thereon, whose angular position can also be detected to determine the orientation of the steerable road wheel 22.

[0088] The corresponding sensor used to detect the rotation angle is also part of system 14.

[0089] Only a single system 14 is shown here, which includes RWA 16 and FBA 18. However, in general, the steering system 12 may also include two separate systems 14, each containing only a single actuator.

[0090] In this respect, system 14 includes at least one actuator, such as RWA 16 or FBA 18, with an electric motor 24 and belt drive 26, corresponding sensors, and evaluation equipment 44.

[0091] Furthermore, according to this example, the evaluation device 44 of system 14 is coupled to a low-pass filter 46. The low-pass filter 46 can be used to attenuate high-frequency interference.

[0092] Additionally, the evaluation device 44 is coupled to the user interface 48 of the vehicle 10. The evaluation device 44 can use the user interface 48 to send notifications to the driver.

[0093] Furthermore, the evaluation device 44 is coupled to the control device 20. For example, the evaluation device 44 can output adjustment signals to the control device 20, and thus affect the function of the steering system 12 and the actuators.

[0094] Typically, the evaluation device 44 can also be part of the control device 20.

[0095] Obviously, the steering system 12 can also have multiple similar and typically functional components, such as multiple steering wheel sensors 38, to ensure redundancy.

[0096] The steering system 12 shown here is a front axle steering system. The vehicle 10 and the steering system 12 may also optionally have further steerable road wheels 22, such as rear wheels, coupled to an additional joint or a separate RWA 16.

[0097] Figure 2 A schematic diagram of the belt drive 26 of system 14 according to the example disclosed herein is shown.

[0098] The belt drive 26 includes a motor shaft 50 and an output shaft 52. The motor shaft 50 and the output shaft 52 are coupled to each other by a toothed belt 54, such that, at least when the slippage of the toothed belt 54 is negligible, rotation of the motor shaft 50 causes rotation of the output shaft 52.

[0099] The motor shaft 50 is coupled to the electric motor 24, which is capable of outputting torque to rotate the motor shaft 50.

[0100] The radius difference between the motor shaft 50 and the output shaft 52 defines the transmission ratio of the belt drive 26.

[0101] The output shaft 52 is coupled to an external component to be driven, for example, in FBA 18, to a steering column on which the steering wheel 36 is mounted. In RWA 16, for example, the output shaft 52 is coupled to a pinion or recirculating ball gear, which causes the rack 28 to translate and thus causes the steerable wheel 22 to rotate about the wheel steering axis.

[0102] In this example, the first sensor 56 of system 14 is coupled to motor shaft 50. The first sensor 56 is configured to capture at least a first rotational angle of motor shaft 50 and transmit it to evaluation device 44.

[0103] In this example, the second sensor 58 of system 14 is coupled to the output shaft 52. The second sensor 58 is configured to capture a second rotation angle of the output shaft 52 and transmit it to the evaluation device 44.

[0104] Typically, the second sensor 58 can also be coupled directly or indirectly to another shaft of the output shaft 52. The output shaft 52 is force-transmittedly coupled to said other shaft, the rotation angle of which is detected by the second sensor 58.

[0105] In some examples, an existing motor angle sensor of the actuator can be used as the first sensor 56 for detecting the movement of the motor shaft. In the case of RWA 16, the second sensor 58 can be a rack sensor 32 or a pinion sensor 34, depending on the existing sensor. In the case of FBA 18, a steering wheel sensor 38 or a steering column sensor can be used as the second sensor 58, depending on the existing sensor. The steering column sensor is designed to detect rotation of the steering column. Since at least one of the aforementioned sensors is already present in RWA 16 and FBA 18 for controlling the steering system, the methods and steering system 12 of the examples disclosed herein do not necessarily require additional sensors to provide the described functionality.

[0106] Figure 3 Another schematic diagram of a belt drive 26 according to the example disclosed herein is shown. The belt drive 26 according to this example differs from the previous example in that it has an additional tensioning device 60 configured to change the belt tension of the toothed belt 54. For this purpose, the tensioning device 60 can be moved, thereby affecting the length of the toothed belt 54, causing a change in its belt tension. For example, the tensioning device 60 may be spring-mounted.

[0107] Figure 4 A schematic diagram of a method for operating an actuator having a belt drive 26, based on an example disclosed herein, is shown. Optional exemplary steps are indicated by dashed lines.

[0108] In an optional exemplary step S2, the evaluation device 44 determines whether the driver is inside the vehicle. For this purpose, the evaluation device 44 can be coupled, for example, to a component indicating whether the vehicle 10 is locked and / or whether a door has been opened. Alternatively, internal sensors can also be used to determine the presence of the driver.

[0109] In the next optional exemplary step S4, the evaluation device 44 determines whether manual torque is applied to the steering wheel 36. For this purpose, a steering wheel sensor 38 can be used. Alternatively or additionally, a torque sensor, configured to detect torque acting on the steering wheel 36 and / or steering column, can also be used. Furthermore, a HOOD sensor 40 can be used to determine whether there is hand contact with the steering wheel 36.

[0110] In some examples, the following process depends on the absence of a driver inside and / or the driver not applying any torque to the steering wheel 36.

[0111] The method then includes an exemplary step S6, in which a specified torque is applied to the motor shaft 50. This can be achieved using an electric motor 24 coupled to a belt drive 26.

[0112] Torque can be a test torque whose characteristics are specified, such as the amplitude, duration, and / or frequency of the applied test torque. For this purpose, the evaluation device 44 can, for example, output an adjustment signal to the control device 20, which then correspondingly controls the electric motor 24.

[0113] Alternatively, the specified torque could be a torque applied during the operation of system 14, but not by the driver. For example, the vehicle control device 42 could autonomously control the vehicle. By coupling the evaluation device 44 to the vehicle control device 42, the evaluation device 44 could acquire information about the characteristics of the applied torque. Of course, the control device 20 could also control the operation of the actuators and transmit this information to the evaluation device 44, making it aware of the applied torque.

[0114] In some examples, tension can also be determined when the driver experiences steering control and generates a counter-torque relative to the motor torque. Typically, this method results in reduced accuracy. However, specific operating conditions can be selected to ensure sufficient accuracy. For example, this method can be used only when high motor torque and a nearly constant steering wheel speed are present, or when the steering wheel 36 is aligned according to a simulated end stop. Of course, this method can also be transferred to RWA 16 accordingly.

[0115] Optionally, exemplary step S6 can be extended by step S8. Correspondingly, the torque applied to the motor shaft 50 is variable for a given test interval and exhibits amplitude and / or frequency variations within the test interval. This allows, for example, the evaluation of frequency-dependent properties of the belt drive 26.

[0116] Following step S6, in exemplary step S10, a first rotation angle of the motor shaft 50 is detected by the first sensor 56 and transmitted to the evaluation device 44.

[0117] In the subsequent step S12, the second rotation angle of the output shaft 52 (or another shaft coupled to the output shaft 52) ​​is detected by the second sensor 58 and transmitted to the evaluation device 44.

[0118] The exemplary method can then be continued in different ways depending on whether it is being executed in test mode during actuator installation or during normal actuator operation.

[0119] In test mode, in the next step S14, the evaluation device 44 determines the response time of the second shaft or output shaft 52 based on the torque applied to the motor shaft 50, the first rotation angle, and the second rotation angle.

[0120] Then, in exemplary step S16, the evaluation device 44 estimates the belt tension of the toothed belt 54 based on the determined reaction time and system parameters.

[0121] During normal operation of the actuator, the evaluation device 44 determines additional system variables in an optional exemplary step S18 following step S12, such as the torque gradient of the torque applied to the motor shaft 50, the first rotation angle gradient of the first rotation angle, and the second rotation angle gradient of the second rotation angle. For this purpose, the evaluation device 44 can use a differentiator.

[0122] Then, the evaluation device 44 estimates the belt tension of the toothed belt 54 in step S20. In this process, the evaluation device 44 considers the torque applied to the motor shaft 50, the first rotation angle of the motor shaft 50, the second rotation angle of the output shaft 52 (or other shaft), and additional system variables, particularly the torque gradient, the first rotation angle gradient, and the second rotation angle gradient.

[0123] This means that the belt tension of the toothed belt 54 can be estimated in different ways. These procedures are specifically tuned for either test or normal operation of the actuator.

[0124] The method can continue from step S16 or step S20, with optional steps S22, S24, S26, S28 and / or S30.

[0125] In optional step S22, the electric motor 24 applies a reverse torque to the motor shaft 50, specifically after a specified time period following the application of torque in step S6. This allows the actuator to stop or return to its initial position, for example, when a method is executed according to a specific test procedure.

[0126] Optional exemplary step S24 specifies that the evaluation device 44, in step S16 or S20, considers the friction and / or elasticity of the output shaft 52 and the components arranged in the force path between the output shaft 52 and the shaft to which the second rotation angle is detected. Alternatively, the friction and / or elasticity affecting the force transmission between the output shaft 52 and the second shaft are considered. This allows for a more accurate determination of the belt tension of the toothed belt 54.

[0127] According to the optional exemplary step S26, the evaluation device 44 estimates the frictional force of the belt drive 26, which allows for a more accurate assessment of its properties. In this process, the evaluation device 44 considers the torque applied to the motor shaft 50, the first rotation angle, the second rotation angle, and additional system variables, particularly the torque gradient, the first rotation angle gradient, and the second rotation angle gradient.

[0128] In an optional exemplary step S28, the evaluation device 44 compares the estimated belt tension of the toothed belt 54 with at least one specified tension threshold.

[0129] Based on the comparison from optional step S28, if the estimated belt tension is less than the tension threshold, the evaluation device 44 outputs a notification to the driver via user interface 48 in a subsequent optional exemplary step S30.

[0130] Additionally or alternatively, if the estimated belt tension is less than the tension threshold, the evaluation device 44 can cause power limiting. For this purpose, the evaluation device 44 can, for example, output an adjustment signal to the control device 20 and / or the vehicle control device 42.

[0131] According to the examples disclosed herein, different tension thresholds can be considered for different measures in step S30.

[0132] Figure 5 This is a block diagram of an exemplary programmable circuit platform 500, which is configured to perform and / or instantiate... Figure 4 The exemplary machine-readable instructions and / or exemplary operations are provided to implement the embodiments disclosed herein. The programmable circuit platform 500 may be, for example, a control device, an electronic control unit (ECU), a self-learning machine (such as a neural network), or any other type of computing and / or electronic device.

[0133] The programmable circuit platform 500 illustrated includes a programmable circuit 512. The programmable circuit 512 illustrated is hardware. For example, the programmable circuit 512 can be implemented using one or more integrated circuits, logic circuits, field-programmable gate arrays (FPGAs), microprocessors, central processing units (CPUs), graphics processing units (GPUs), vision processors (VPUs), digital signal processors (DSPs), and / or microcontrollers from any desired family or manufacturer. The programmable circuit 512 can be implemented using one or more semiconductor-based (e.g., silicon-based) devices.

[0134] The programmable circuit 512 shown in the example includes local memory 513 (such as cache, registers, etc.). The programmable circuit 512 of the example communicates via bus 518 with main memories 514, 516, including volatile memory 514 and non-volatile memory 516. The volatile memory 514 may be implemented using synchronous dynamic random access memory (SDRAM), dynamic random access memory (DRAM), RAMBUS® dynamic random access memory (RDRAM), and / or any other type of RAM device. The non-volatile memory 516 may be implemented using flash memory and / or any other desired type of storage device. Access to the main memories 514, 516 of the example shown is controlled by a memory controller 517. In some examples, the memory controller 517 may be implemented using one or more integrated circuits, logic circuits, microcontrollers, or any other type of circuitry from any desired series or manufacturer for managing the flow of data into and out of the main memories 514, 516.

[0135] The programmable circuit platform 500 shown in the example also includes interface circuitry 520. Interface circuitry 520 can be implemented in hardware according to any type of interface standard, such as Controller Area Network (CAN), Ethernet interface, Universal Serial Bus (USB) interface, Bluetooth interface, Near Field Communication (NFC) interface, Peripheral Component Interconnect (PCI) interface, and / or Peripheral Component Interconnect High Speed ​​(PCIe) interface.

[0136] In the example shown, one or more input devices 522 are connected to interface circuitry 520. Input devices 522 allow users (such as human users, machine users, etc.) to input data and / or commands into programmable circuitry 512. Input devices 522 can be implemented using, for example, audio sensors, microphones, cameras (static or dynamic), buttons, touchscreens, and / or voice recognition systems.

[0137] One or more output devices 524 are also connected to the interface circuitry 520 of the illustrated example. The output devices 524 may be implemented as, for example, display devices (such as light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), liquid crystal displays (LCDs), in-plane switching (IPS) displays, touchscreens, etc.), haptic output devices, and / or speakers. Therefore, the interface circuitry 520 of the illustrated example typically includes a graphics driver card, a graphics driver chip, and / or graphics processor circuitry (such as a GPU).

[0138] The interface circuit 520 of the example shown also includes communication devices such as transmitters, receivers, transceivers, modems, residential gateways, wireless access points, and / or network interfaces to facilitate data exchange with external devices (such as any type of computing device) via network 526. This communication can be achieved, for example, via Ethernet connections, digital subscriber line (DSL) connections, telephone line connections, coaxial cable systems, satellite systems, beyond-line-of-sight wireless systems, line-of-sight wireless systems, cellular telephone systems, fiber optic connections, etc.

[0139] The programmable circuit platform 500 shown in the example also includes one or more mass storage disks or storage devices 528 for storing firmware, software, and / or data. Examples of such mass storage disks or storage devices 528 include magnetic storage devices (such as floppy disks, drives, hard disk drives (HDDs), etc.), optical storage devices (such as Blu-ray discs, optical discs (CDs), digital video discs (DVDs), etc.), disk array (RAID) systems, and / or solid-state storage disks or storage devices (such as flash memory devices and / or solid-state drives (SSDs)).

[0140] can be Figure 4 The machine-readable instructions 532 implemented by the machine-readable instructions can be stored in a mass storage device 528, a volatile memory 514, a non-volatile memory 516, and / or at least one removable non-transitory computer-readable storage medium (such as an optical disc or digital video disc).

[0141] Exemplary methods, apparatuses, systems, and articles of manufacture for monitoring and adjusting belt tension are disclosed herein. Other examples and combinations thereof include the following: Example 1 Example 1 includes an apparatus for operating an actuator with a belt drive, the apparatus comprising: an interface circuit communicatively coupled to a first sensor and a second sensor; machine-readable instructions; and at least one programmable circuitry; the programmable circuitry being configured to apply a specified torque to a motor shaft of the belt drive, determine a first rotation angle of the motor shaft based on a first output signal from the first sensor, determine a second rotation angle of an output shaft of the belt drive based on a second output signal from the second sensor, determine a response time of either the second shaft or the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle, estimate the tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time, and adjust the operation of the actuator according to the tension.

[0142] Example 2 includes the apparatus according to Example 1, wherein, after a specified time interval following the application of torque to the motor shaft, one or more programmable circuits of the at least one programmable circuit are configured to apply a reverse torque to the motor shaft, the reverse torque being in the opposite direction to the torque.

[0143] Example 3 includes the apparatus according to any one of Examples 1 to 2, wherein if the second rotation angle is detected with respect to the second shaft, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of the components arranged in the force path between the output shaft and the second shaft.

[0144] Example 4 includes an apparatus according to any one of Examples 1 to 3, wherein the specified torque is a specified test torque or a torque specified during operation of the actuator.

[0145] Example 5 includes an apparatus according to any one of Examples 1 to 4, wherein one or more of the at least one programmable circuits are configured to estimate the friction of the belt drive based on the applied torque, the first rotation angle, and the second rotation angle.

[0146] Example 6 includes an apparatus according to any one of Examples 1 to 5, wherein one or more of the at least one programmable circuits have an evaluation frequency below a specified frequency threshold.

[0147] Example 7 includes an apparatus according to any one of Examples 1 to 6, wherein the specified torque is variable for a specified test interval and has amplitude and / or frequency variations within the test interval.

[0148] Example 8 includes a device according to any one of Examples 1 to 7, wherein the specified torque is applied when the driver does not apply any torque to a steering wheel that is at least indirectly coupled to the actuator, and / or the driver is not inside the vehicle.

[0149] Example 9 includes a device according to any one of Examples 1 to 8, wherein if the estimated belt tension is less than a tension threshold, one or more of the at least one programmable circuits will cause a notification to be output, and / or will cause a power limit on the actuator and / or external components.

[0150] Example 10 includes a method comprising: applying a specified torque to a belt-driven motor shaft of an actuator; determining a first rotation angle of the motor shaft based on a first output signal from a first sensor; determining a second rotation angle of the belt-driven output shaft based on a second output signal from a second sensor; determining a response time of the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle; estimating the tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time; and adjusting the operation of the actuator based on the estimated tension.

[0151] Example 11 includes the method according to Example 10, further comprising: after a specified time interval following the application of the torque to the motor shaft, applying a reverse torque to the motor shaft, the reverse torque being in the opposite direction to the torque.

[0152] Example 12 includes the method according to any one of Examples 10 to 11, wherein if the second rotation angle is detected with respect to the second axis, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of the components arranged in the force path between the output shaft and the second axis.

[0153] Example 13 includes the method according to any one of Examples 10 to 12, wherein the specified torque is a specified test torque or a torque specified during operation of the actuator.

[0154] Example 14 includes the method according to any one of Examples 10 to 13, wherein the specified torque is applied in a variable manner for a specified test interval and has amplitude and / or frequency variations within the test interval.

[0155] Example 15 includes the method according to any one of Examples 10 to 14, wherein the specified torque is applied when the driver does not apply any torque to the steering wheel that is at least indirectly coupled to the actuator, and / or the driver is not inside the vehicle.

[0156] Example 16 includes a non-transitory machine-readable storage medium comprising instructions to cause at least one programmable circuitry to perform at least the following operations: applying a specified torque to a belt-driven motor shaft of an actuator; determining a first rotation angle of the motor shaft based on a first output signal from a first sensor; determining a second rotation angle of the belt-driven output shaft based on a second output signal from a second sensor; determining a response time of the output shaft based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle; estimating the tension of a toothed belt coupling the output shaft to the motor shaft based on the determined response time; and adjusting the operation of the actuator based on the tension.

[0157] Example 17 includes a non-transitory machine-readable storage medium according to Example 16, wherein, after a specified time interval following the application of torque to the motor shaft, one or more programmable circuits of the at least one programmable circuit are configured to apply a reverse torque to the motor shaft, the reverse torque being in the opposite direction to the torque.

[0158] Example 18 includes a non-transitory machine-readable storage medium according to any one of Examples 16 to 17, wherein if the second rotation angle is detected with respect to a second axis, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of a component arranged in a force path between the output shaft and the second axis.

[0159] Example 19 includes a non-transitory machine-readable storage medium according to any one of Examples 16 to 18, wherein the specified torque is applied when the driver does not apply any torque to a steering wheel that is at least indirectly coupled to the actuator, and / or the driver is not inside the vehicle.

[0160] Example 20 includes a non-transitory machine-readable storage medium according to any one of Examples 16 to 19, wherein if the estimated band tension is less than a tension threshold, one or more of the at least one programmable circuits will cause a notification to be output, and / or will cause power limiting of the actuator and / or external components.

Claims

1. An apparatus for operating an actuator having a belt drive, the apparatus comprising: An interface circuit that is communicatively coupled to the first and second sensors; Machine-readable instructions; as well as At least one programmable circuit is used for: This causes a specified torque to be applied to the belt-driven motor shaft. Based on the first output signal from the first sensor, the first rotation angle of the motor shaft is determined. Based on the second output signal from the second sensor, the second rotation angle of the output shaft of the belt drive is determined. The response time of the output shaft is determined based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle. Based on the determined reaction time, the tension of the toothed belt coupling the output shaft to the motor shaft is estimated, and The operation of the actuator is adjusted based on the tension.

2. The apparatus according to claim 1, wherein, After a specified time interval following the application of torque to the motor shaft, one or more of the at least one programmable circuits are configured to apply a reverse torque to the motor shaft, the reverse torque being in the opposite direction to the torque.

3. The apparatus according to claim 1, wherein, If the second rotation angle is obtained by detection for the second axis, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of the components arranged in the force path between the output shaft and the second axis.

4. The apparatus according to claim 1, wherein, The specified torque is either a specified test torque or a torque specified during operation of the actuator.

5. The apparatus according to claim 1, wherein, One or more of the at least one programmable circuits are used to estimate the friction of the belt drive based on the applied torque, the first rotation angle, and the second rotation angle.

6. The apparatus according to claim 1, wherein, One or more of the at least one programmable circuits have an evaluation frequency lower than a specified frequency threshold.

7. The apparatus according to claim 1, wherein, The specified torque is variable for a specified test interval and has amplitude and / or frequency variations within the test interval.

8. The apparatus according to claim 1, wherein, The specified torque is applied when the driver does not apply any torque to the steering wheel, which is at least indirectly coupled to the actuator, and / or when the driver is not inside the vehicle.

9. The apparatus according to claim 1, wherein, If the estimated belt tension is less than the tension threshold, one or more of the at least one programmable circuits will cause a notification to be output, and / or will cause a power limit on the actuator and / or external components.

10. A method, the method comprising: To apply a specified torque to the belt-driven motor shaft of the actuator; Based on the first output signal of the first sensor, the first rotation angle of the motor shaft is determined; Based on the second output signal of the second sensor, the second rotation angle of the output shaft of the belt drive is determined; The response time of the output shaft is determined based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle; Based on the determined reaction time, estimate the tension of the toothed belt that couples the output shaft to the motor shaft; and The operation of the actuator is adjusted based on the estimated tension.

11. The method of claim 10, further comprising: After a specified time interval following the application of the torque to the motor shaft, a reverse torque is applied to the motor shaft, the direction of which is opposite to that of the torque.

12. The method according to claim 10, wherein, If the second rotation angle is obtained with respect to the second shaft, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of the components arranged in the force path between the output shaft and the second shaft.

13. The method according to claim 10, wherein, The specified torque is either a specified test torque or a torque specified during operation of the actuator.

14. The method of claim 10, wherein, The specified torque is applied in a variable manner for a specified test interval, and has amplitude and / or frequency variations within the test interval.

15. The method according to claim 10, wherein, The specified torque is applied when the driver does not apply any torque to the steering wheel, which is at least indirectly coupled to the actuator, and / or when the driver is not inside the vehicle.

16. A non-transitory machine-readable storage medium comprising instructions to cause at least one programmable circuit to at least: To apply a specified torque to the belt-driven motor shaft of the actuator. Based on the first output signal from the first sensor, the first rotation angle of the motor shaft is determined. Based on the second output signal from the second sensor, the second rotation angle of the output shaft of the belt drive is determined. The response time of the output shaft is determined based on the torque applied to the motor shaft, the first rotation angle, and the second rotation angle. Based on the determined reaction time, the tension of the toothed belt coupling the output shaft to the motor shaft is estimated, and The operation of the actuator is adjusted based on the tension.

17. The non-transitory machine-readable storage medium according to claim 16, wherein, After a specified time interval following the application of torque to the motor shaft, one or more of the at least one programmable circuits are configured to apply a reverse torque to the motor shaft, the reverse torque being in the opposite direction to the torque.

18. The non-transitory machine-readable storage medium according to claim 16, wherein, If the second rotation angle is obtained for the second axis, the belt tension is estimated based on the elasticity and friction of the output shaft and the elasticity and friction of the components arranged in the force path between the output shaft and the second axis.

19. The non-transitory machine-readable storage medium according to claim 16, wherein, The specified torque is applied when the driver does not apply any torque to the steering wheel, which is at least indirectly coupled to the actuator, and / or when the driver is not inside the vehicle.

20. The non-transitory machine-readable storage medium according to claim 16, wherein, If the estimated belt tension is less than the tension threshold, one or more of the at least one programmable circuits will cause a notification to be output, and / or will cause a power limit on the actuator and / or external components.

Images