METHOD, SYSTEM AND DEVICE FOR DETECTING HANDS ON THE STEERING WHEEL

Abstract

Method for detecting hands on the steering wheel, the method comprising: Receiving a handwheel angle signal from a sensor (106) associated with a handwheel of a vehicle; Generating a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; Synchronizing the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; Generating a driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal; and Determine whether the vehicle driver's hands are on the handwheel, based on the driver torque estimation signal.

Description

TECHNICAL AREA

[0001] This disclosure relates to steering systems and in particular to a method, a system and a device for detecting hands on the steering wheel. BACKGROUND OF THE INVENTION

[0002] A vehicle, such as a passenger car, truck, sport utility vehicle, crossover, minivan, personal watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable means of transport, typically has a steering system, such as an electronic power steering system (EPS system), a steer-by-wire (SbW) system, a hydraulic steering system, or another suitable steering system. The steering system of such a vehicle typically controls various aspects of the vehicle's steering, including providing steering assistance to the driver, controlling the vehicle's steerable wheels, and the like.

[0003] DE 10 2015 016 217 A1 discloses an electric power steering device and a control method for determining whether a driver is holding the steering wheel. An electrical signal corresponding to the steering wheel's rotation angle is output by a steering angle sensor. Additionally, a steering angle velocity and a steering angle acceleration are determined for a steering torque model equation. Using this steering torque model equation, a steering torque model value is calculated, which is then used to determine whether the driver is holding the steering wheel. EXPLANATION OF THE INVENTION

[0004] The object of the invention is to provide an improved method, an improved system and an improved device for detecting hands on the steering wheel.

[0005] To solve the problem, a method with the features of claim 1, a system with the features of claim 9, and a device with the features of claim 17 are provided. Advantageous embodiments of the invention can be found in the dependent claims, the description, and the drawings.

[0006] These and other aspects of the present disclosure are disclosed in the following detailed description of the embodiments, the attached claims and the accompanying figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The revelation is best understood by means of the following detailed description, when read in conjunction with the accompanying drawings. It is emphasized that, in accordance with common practice, the various features in the drawings are not to scale. On the contrary, the dimensions of the various features have been arbitrarily enlarged or reduced for clarity. Fig. Figure 1 generally shows a vehicle in accordance with the principles of the present disclosure. Fig. Figure 2 shows a control unit in general, in accordance with the principles of the present disclosure. Fig. Figure 3 shows a general ball recirculation steering gear according to the principles of the present disclosure. Fig. Figure 4 shows a general hydraulic steering system with ball steering gear according to the principles of the present disclosure. Fig. 5A and Fig. Figure 5B shows a general scheme of a control system of a hydraulic steering system according to the principles of the present disclosure. Fig. Figure 6 shows a general scheme of a system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figures 7A-7B generally show a scheme of an alternative system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figure 8 shows a general scheme of an alternative system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figures 9A-9B generally show a scheme of an alternative system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figure 10 shows a general scheme of an alternative system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figure 11 shows a general scheme of an alternative system for detecting hands on the steering wheel according to the principles of the present disclosure. Fig. Figure 12 is a flowchart that generally shows a method for detecting hands on the steering wheel according to the principles of the present disclosure. DETAILED DESCRIPTION

[0008] The following discussion relates to various embodiments of the disclosure. Although one or more of these embodiments may be preferred, the disclosed embodiments should not be interpreted or otherwise used as limiting the scope of the disclosure, including the claims. Furthermore, the person skilled in the art will understand that the following description has a broad scope and that the discussion of any particular embodiment is intended only as an example of that embodiment and is not meant to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

[0009] As described, a vehicle, such as a passenger car, truck, sport utility vehicle, crossover, minivan, personal watercraft, aircraft, off-road vehicle, recreational vehicle, or other suitable means of transport, typically includes a steering system, such as an electronic power steering system (EPS system), a steer-by-wire steering system (SbW system), a hydraulic steering system, or another suitable steering system. The steering system of such a vehicle generally controls various aspects of the vehicle's steering, including providing steering assistance to a driver, controlling the vehicle's steerable wheels, and the like.

[0010] A hydraulic steering system typically uses a power steering pump to supply pressurized hydraulic fluid to either a recirculating ball steering gear or a rack and pinion steering gear. The level of torque assistance (e.g., to the driver) provided by such a steering system is determined by the amount of torque the driver applies to a steering valve integrated into the steering gear.

[0011] A cross-section of a recirculating ball steering gear is generally shown in Fig. Figure 3 shows the gearbox. The gearbox includes an input shaft that is functionally connected to the vehicle's handwheel. When torque is applied to the input shaft, a valve assembly is actuated to generate auxiliary pressure in either cavity A or cavity B, depending on the direction of the torque, to assist the vehicle's steering. A worm gear is mounted on the underside of the valve assembly, which exerts a thrust force on a rack. As the valve assembly rotates within the steering gearbox, the rack moves along the axis of the worm gear in a rack bore. The rack has teeth that engage with teeth on a pitman shaft. As the rack moves axially within the rack bore, the pitman shaft rotates about its axis. A pitman arm is mounted at the lower end of the pitman shaft, connecting it to a linkage in the vehicle.When the steering column shaft rotates, the steering column lever swings in an arc. This moves the steering linkage inside the vehicle, causing the front wheels to turn in order to steer the vehicle.

[0012] Some hydraulic steering systems incorporate a magnetic actuator in the valve assembly. Such a system allows advanced algorithms to be implemented within the hydraulic system, such as variable force application, caster correction, active damping, active return, and similar functions. It can also enable the system to receive torque commands from external algorithms on the vehicle, which can then be incorporated into the output torque.

[0013] A cross-section through a recirculating ball steering gear of such a hydraulic steering system (e.g., including the magnetic actuator) is generally shown in Fig. Figure 4 illustrates this. As generally shown, the assistance and connection between the handwheel and the road wheels are functionally identical to a basic gearbox. The gearbox incorporates a magnetic actuator integrated into the valve assembly to generate additional force to assist or resist the driver under certain steering conditions. Under these conditions, a control unit supplies current to a coil that determines the amount of torque provided by the magnetic actuator.

[0014] A high-level block diagram of the hydraulic steering system controls is shown in Fig. 5A and Fig. 5B is shown in general terms. A measurement of the differential pressure across the piston in the steering system, along with various vehicle signals such as vehicle speed, handwheel speed, and handwheel angle, as well as an estimate of the driver's torque, are used to generate a desired torque command. An external torque command signal and an external torque enable signal can also be received by the vehicle (e.g., from the control unit). The external torque enable signal, along with signals such as differential pressure, handwheel angle, vehicle speed, and a signal to detect hands on the steering wheel, is evaluated to determine whether the conditions are acceptable for the external torque command to be granted.

[0015] An external command limiting block then determines the amount of the external signal to be applied. A final torque block combines the internal torque command and the external torque command to provide a final torque command. This torque command is passed to a current command module, which converts the desired torque command into a required current command applied to the coil of the magnetic actuator in the steering gear. The current command, along with the measured differential pressure, is used to generate an estimate of the driver's torque, which can be used in the next loop.

[0016] The estimated driver torque can be used by a hands-on-the-wheel detection block to generate a signal indicating whether the driver's hands are on the steering wheel. An example of a hands-on-the-wheel detection block is commonly found in... Fig. Figure 6 illustrates this. The estimated driver torque signal is filtered. The absolute value of the filtered estimated driver torque, along with the vehicle speed, is used to select a gain value from a lookup table. This gain value typically has a higher positive value when the torque level is high and a higher negative value when the torque is near zero. The gain value is multiplied by the periodic rate of the hands-on-the-wheel detection block and integrated over time. A limit of 1 and -1 is applied to the integrated signal. The limited signal can be filtered before the final hands-on-the-wheel detection signal is output.

[0017] The estimated driver torque determined in this application is the torque applied across the hydraulic valve assembly. While this provides a reasonable estimate of driver torque at slow handwheel speeds and under steady-state conditions, it does not account for the inertia, damping, and friction effects of the handwheel and steering column. This can lead to errors during rapid steering maneuvers.

[0018] Accordingly, systems and methods such as those described here, configured to enable improved detection of hands on the steering wheel, may be desirable. In some embodiments, the systems and methods described here may be configured to use a handwheel angle signal in addition to the estimated driver torque signal to improve performance during rapid handwheel movements.

[0019] Fig. Figures 7A-7B show a general block diagram of the controls for a steering system that includes a hands-on-the-steering-wheel detection block. The systems and methods described here can be configured to use two input signals: a hands-on-the-wheel angle signal and a hands-on-the-wheel angle update signal. The systems and methods described here can be configured to receive the hands-on-the-wheel angle signal from a serial communication device or system of the vehicle. This signal may not be updated at the same periodic rate as the hands-on-the-wheel detection block. The systems and methods described here can be configured to set the hands-on-the-wheel angle update signal to true when the hands-on-the-wheel signal is updated on the serial communication bus.

[0020] The systems and methods described here can be configured to set the handwheel angle signal to false if the handwheel angle signal from a previous loop is retained. The systems and methods described here can also be configured to use the updated handwheel angle signal to change its value at the periodic rate of hand detection on the steering wheel (e.g., even though the handwheel angle signal from the serial communication has not changed).

[0021] Fig. Figure 8 shows the general block for detecting hands on the steering wheel. The systems and procedures described here can be configured to estimate torque from a torque estimation block (e.g., from...). Fig. 7A-7B) and use elements that reflect the dynamic effects of the handwheel and steering column as a function of handwheel speed and handwheel acceleration.

[0022] In some embodiments, the systems and methods described here can be configured to calculate a handwheel velocity (HWS) and a handwheel acceleration (Acc) using the handwheel angle (HWA). For example, the systems and methods described here can be configured to calculate the HWS at time step 1 from the HWA at time step 0 and at time step 2, which may be defined as follows: HWS1=(HWA0−HWA2) / (2*dT), where dT=time difference between time steps−t

[0023] The systems and procedures described here can be configured to use memory blocks assigned to the control unit to store HWS values ​​at additional time steps (e.g., HWS2, HWS3, HWS4, or other suitable time steps). The systems and procedures described here can be configured to calculate the Acc at time step 2 using the HWS at time steps 1 and 3, which can be defined as follows: Acc2=(HWS1−HWS3) / (2*dT), where dT=time difference between time steps.

[0024] The systems and procedures described here can be configured to use the memory blocks to store values ​​of Acc at additional time steps (e.g. Acc3, Acc4, or other suitable time steps).

[0025] As generally stated, this means that the earliest time step at which HWS can be calculated is delayed by one time step relative to the current time step, and that the earliest time step at which Acc can be calculated is delayed by two time steps relative to the current time step. To minimize the error in the estimated driver torque during rapid steering maneuvers, the systems and procedures described here can be configured to synchronize the handwheel-related signals so that the calculated HWS and Acc values ​​refer to the same time step. For example: delayed HWS = HWS2 and delayed Acc = Acc2.

[0026] In some embodiments, the systems and methods described herein can be configured to apply an additional time step delay for a total of three time steps to estimate the value of HWS and Acc when the hands-on-the-wheel detection block is calculated but the HWA has not been updated. The values ​​for HWS and Acc can be incremented linearly between HWS2 and HWS3, and Acc2 and Acc3, respectively. For example, if the hands-on-the-wheel angle is updated every fifth time the systems and methods described herein calculate the hands-on-the-wheel detection block, the systems and methods described herein can be configured to calculate an increment for HWS equal to one-fifth of the difference between HWS2 and HWS3, which can be defined as follows: HWSInc=(HWS2−HWS3) / 5

[0027] The systems and procedures described here can be configured to detect hands on the steering wheel (HWS) on every execution of the block. Inc Add to the previous delayed HWS value until the HWA signal is updated.

[0028] Similarly, the systems and procedures described here can be configured to calculate an Acc increment that is one-fifth of the difference between Acc2 and Acc3, which can be defined as follows: AccInc=(Acc2−Acc3) / 5

[0029] The systems and procedures described here can be configured so that Acc Inc With each execution of the block for detecting hands on the steering wheel, the value is added to the previous delayed ACC value until the HWA signal is updated.

[0030] Fig. Figures 9A-9B generally illustrate the delayed handwheel angle signal block, which implements the delayed HWA-related signals as described. When the update signal value is true, the systems and procedures described here can be configured to output the delayed HWS signals and the delayed Acc signals along with the HWS signals. Inc and Acc Inc calculate, as in Fig. 10 is generally presented.

[0031] If the value of the update signal is incorrect, the systems and procedures described herein can be configured to replace the delayed HWS and Acc signals using the values ​​of the HWS signals. Inc and Acc Inc (which, for example, are generally in Fig. (shown in 11) increase.

[0032] Again with reference to Fig. 8. The systems and methods described here can be configured to calculate a driver torque estimation signal and forward the signal to the integration routine for hands-on-steering detection. The systems and methods described here can be configured to calculate the driver torque estimation signal by determining the sum of four signals representing a damping component, an inertial component, a friction component, and a valve torque component. The damping component is calculated by multiplying the delayed handwheel speed signal by a damping coefficient scale value.

[0033] The inertia component is calculated by multiplying the delayed handwheel acceleration signal by a handwheel inertia scale value. The friction component is calculated by multiplying a friction direction signal by a friction magnitude scale value. The initial friction direction signal is determined by the sign of the delayed handwheel velocity signal. If the delayed handwheel velocity signal is positive, the initial direction signal is 1. If the delayed handwheel velocity signal is negative, the initial direction signal is -1. If the delayed handwheel velocity signal is zero, the initial direction signal is equal to the value from the previous loop.

[0034] The systems and procedures described here can be configured such that a low-pass filter is applied to the initial friction direction signal to obtain a final friction direction signal that transitions from 1 to -1 or from -1 to 1 at a slower rate. The valve torque component signal is the Trq Est signal of the torque estimation block in Fig. 7A-7B, which is equipped with a delay. The delay is calibratable so that the Trq Est signal can be synchronized with the delayed handwheel angle signals (which can, for example, minimize, reduce, or eliminate errors during rapid steering maneuvers).

[0035] It should be noted that the values ​​for the damping coefficient, handwheel inertia, and friction scale can be implemented in various forms. They can be constant values ​​in the code, constant calibration values, or values ​​derived from calibratable lookup tables depending on other signals such as vehicle speed.

[0036] In some embodiments, the systems and methods described herein can be configured to provide a means for calculating a hands-on-the-steer detection signal. The systems and methods described herein can be configured to use a handwheel angle signal received from the vehicle. The systems and methods described herein can be configured to calculate a handwheel speed signal and a handwheel acceleration signal from the handwheel angle signal. The systems and methods described herein can be configured to delay the handwheel speed signals and the handwheel acceleration signals in order to synchronize them.

[0037] The systems and methods described here can be configured to calculate the handwheel velocity and handwheel acceleration signals for each execution of the hands-on-the-steering-wheel detection block (e.g., even when the handwheel angle signal is not updated). The systems and methods described here can be configured to linearly modify the signals for the time steps during which the handwheel angle signal is not updated. The systems and methods described here can be configured to estimate the driver torque using damping, inertia, and friction. The systems and methods described here can be configured to use a delayed estimate of the valve torque to synchronize the torque estimate with the delayed signals generated by the handwheel.The systems and procedures described here can be configured to use a filter to reduce the rate of change of the applied friction direction.

[0038] In some embodiments, the systems and methods described herein can be configured to receive a handwheel angle signal from a sensor associated with a vehicle's handwheel. The handwheel is associated with an EPS steering system, a SbW steering system, a hydraulic steering system (e.g., with a magnetic actuator integrated into a valve assembly of the hydraulic steering system), or another suitable steering system of the vehicle.

[0039] The systems and methods described herein can be configured to generate a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal. The systems and methods described herein can be configured to synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal. The systems and methods described herein can be configured to generate a driver torque estimation signal based at least on the delayed handwheel speed signal and the delayed handwheel acceleration signal.For example, the systems and procedures described here can be configured to calculate a damping value by determining a product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value.

[0040] The systems and methods described herein can be configured to calculate an inertia value by determining the product of a handwheel acceleration value, indicated by the delayed handwheel acceleration signal, and a handwheel inertia scale value. The systems and methods described herein can be configured to calculate a friction value by determining the product of a friction direction signal and a friction magnitude scale value. The systems and methods described herein can be configured to generate a delayed valve torque signal by delaying a received valve torque signal. The systems and methods described herein can be configured to generate the driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed torque value signal.The systems and procedures described herein can be configured to determine, based on the driver torque estimation signal, whether the hands of a vehicle driver are on the handwheel.

[0041] Fig. Figure 1 shows a vehicle 10 in general, in accordance with the principles of this disclosure. The vehicle 10 can be any suitable vehicle, such as a passenger car, a truck, a sport utility vehicle, a minivan, a crossover, any other passenger vehicle, a suitable utility vehicle, or any other suitable vehicle. Although the vehicle 10 is shown as a wheeled passenger vehicle for use on roads, the principles of this disclosure can also be applied to other vehicles, such as airplanes, boats, trains, drones, or other suitable vehicles.

[0042] The vehicle 10 comprises a vehicle body 12 and an engine hood 14. A passenger compartment 18 is defined, at least in part, by the vehicle body 12. Another part of the vehicle body 12 defines an engine compartment 20. The engine hood 14 can be movably attached to a part of the vehicle body 12 such that the engine hood 14 provides access to the engine compartment 20 when the engine hood 14 is in a first or open position, and the engine hood 14 covers the engine compartment 20 when the engine hood 14 is in a second or closed position. In some embodiments, the engine compartment 20 can be located at a rear part of the vehicle 10, unlike the generally depicted configuration.

[0043] The passenger compartment 18 can be located behind the engine compartment 20, but it can also be located in front of the engine compartment 20 if the engine compartment 20 is located in the rear part of the vehicle 10. The vehicle 10 can comprise any suitable propulsion system, including an internal combustion engine, one or more electric motors (e.g., of an electric vehicle), one or more fuel cells, a hybrid propulsion system (e.g., of a hybrid vehicle) comprising a combination of an internal combustion engine and one or more electric motors, and / or any other suitable propulsion system.

[0044] In some embodiments, the vehicle 10 may include a gasoline engine, e.g., a spark-ignition engine. In some embodiments, the vehicle 10 may include a diesel engine, such as a compression-ignition engine. The engine compartment 20 houses and / or encloses at least some components of the vehicle 10's drive system. Additionally or alternatively, drive controls such as an accelerator actuator (e.g., an accelerator pedal), a brake actuator (e.g., a brake pedal), a handwheel, and other such components are arranged in the passenger compartment 18 of the vehicle 10. The drive controls can be operated or controlled by a driver of the vehicle 10 and can be directly connected to the corresponding components of the drive system, such as a throttle valve, a brake, a vehicle axle, a vehicle transmission, and the like. In some embodiments, the drive controls can send signals to a vehicle computer (e.g., a computer).Drive-by-wire) transmits data, which in turn can control the corresponding drive component of the drive system. In some embodiments, the vehicle 10 can thus be an autonomous vehicle.

[0045] In some embodiments, the vehicle 10 includes a transmission connected to a crankshaft via a flywheel, clutch, or fluid coupling. In some embodiments, the transmission is a manual transmission. In some embodiments, the transmission is an automatic transmission. In the case of an internal combustion engine or a hybrid vehicle, the vehicle 10 may include one or more pistons that work in concert with the crankshaft to generate a force that is transmitted via the transmission to one or more axles that rotate the wheels 22. If the vehicle 10 includes one or more electric motors, a vehicle battery and / or a fuel cell supplies energy to the electric motors to rotate the wheels 22.

[0046] Vehicle 10 may include automatic vehicle propulsion systems, such as cruise control, adaptive cruise control, automatic braking control, other automatic vehicle propulsion systems, or a combination thereof. Vehicle 10 may be an autonomous or semi-autonomous vehicle, or another suitable vehicle type. Vehicle 10 may have additional or fewer features than those generally described and / or disclosed herein.

[0047] In some embodiments, the vehicle 10 may include an Ethernet component 24, a Controller Area Network (CAN) bus 26, a Media Oriented Systems Transport (MOST) component 28, a FlexRay component 30 (e.g., a brake-by-wire system and the like), and a Local Interconnect Network (LIN) component 32. The vehicle 10 may use the CAN bus 26, the MOST component 28, the FlexRay component 30, the LIN component 32, other suitable networks or communication systems, or a combination thereof, to transmit various information from, for example, sensors inside or outside the vehicle to, for example, various processors or control units inside or outside the vehicle. The vehicle 10 may have additional or fewer features than those generally described and / or disclosed herein.

[0048] In some embodiments, the vehicle 10 may include a steering system, such as an EPS system, a steer-by-wire steering system (which may, for example, include or communicate with one or more control units that control components of the steering system without the use of a mechanical connection between the handwheel and the wheels 22 of the vehicle 10), a hydraulic steering system (which may, for example, include a magnetic actuator integrated into a valve assembly of the hydraulic steering system), or another suitable steering system.

[0049] The steering system may comprise an open-feedback system or mechanism, a closed-feedback system or mechanism, or a combination thereof. The steering system may be configured to receive various inputs, including but not limited to a handwheel position, an input torque, one or more road wheel positions, other suitable inputs or information, or a combination thereof.

[0050] Additionally or alternatively, the inputs may include handwheel torque, handwheel angle, engine speed, vehicle speed, an estimated engine torque command, another suitable input, or a combination thereof. The steering system may be configured to provide a steering function and / or control of the vehicle 10. For example, the steering system may generate an auxiliary torque based on the various inputs. The steering system may be configured to selectively control a motor of the steering system using the auxiliary torque to provide steering assistance to the driver of the vehicle 10.

[0051] In some embodiments, the vehicle 10 may contain a control unit, such as the control unit 100, as is generally found in Fig. Figure 2 is shown. The control unit 100 can be any suitable control unit, such as an electronic control unit or another suitable control unit. The control unit 100 can be configured to control, for example, the various functions of the steering system and / or various functions of the vehicle 10. The control unit 100 can include a processor 102 and a memory 104. The processor 102 can be any suitable processor as described herein. Additionally or alternatively, the control unit 100 can include any number of processors in addition to the processor 102, or other processors. The memory 104 can include a single disk or a plurality of disks (e.g., hard disks) and contains a memory management module that manages one or more partitions within the memory 104.In some embodiments, the memory 104 may comprise flash memory, solid-state memory, or the like. The memory 104 may comprise random access memory (RAM), read-only memory (ROM), or a combination thereof. The memory 104 may contain instructions which, when executed by the processor 102, cause the processor 102 to control at least various aspects of the vehicle 10.

[0052] The control unit 100 can receive one or more signals from various measuring instruments or sensors 106 indicating detected or measured characteristics of the vehicle 10. The sensors 106 can include any suitable sensors, measuring instruments, and / or other suitable mechanisms. For example, the sensors 106 can include one or more torque sensors or devices, one or more handwheel position sensors or devices, one or more engine position sensors or devices, one or more position sensors or devices, other suitable sensors or devices, or a combination thereof. The one or more signals can indicate handwheel torque, handwheel angle, engine speed, vehicle speed, other suitable information, or a combination thereof.

[0053] In some embodiments, the control unit 100 can be configured to enable hand detection on the steering wheel. For example, the control unit 100 can receive a handwheel angle signal from one or more sensors 106 (e.g., a handwheel position sensor 106 or another suitable sensor 106 or another suitable sensor) that are connected to and / or associated with the handwheel and / or steering column of the vehicle 10. Based on a handwheel angle indicated by the handwheel angle signal, the control unit 100 can generate a handwheel speed signal and a handwheel acceleration signal.

[0054] The control unit 100 can synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal. The control unit 100 can generate a driver torque estimation signal based at least on the delayed handwheel speed signal and the delayed handwheel acceleration signal. For example, the control unit 100 can calculate a damping value by determining the product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value.

[0055] The control unit 100 can calculate an inertia value by determining the product of a handwheel acceleration value, indicated by the delayed handwheel acceleration signal, and a handwheel inertia scale value. The control unit 100 can calculate a friction value by determining the product of a friction direction signal and a friction magnitude scale value. The control unit 100 can generate a delayed valve torque signal by delaying a received valve torque signal.

[0056] The control unit 100 can generate the driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed valve torque signal. Based on this driver torque estimation signal, the control unit 100 can determine whether a driver's hands are on the handwheel.

[0057] In some embodiments, the control unit 100 can perform the procedures described herein. However, the procedures described herein, which are performed by the control unit 100, are not to be understood as a limitation, and any type of software running on a control unit or a processor can perform the procedures described herein without exceeding the scope of this disclosure. For example, a control unit, such as a processor running software in a computer device, can perform the procedures described herein.

[0058] Fig.Figure 12 is a flowchart that generally shows a method 300 for detecting hands on the steering wheel according to the principles of the present disclosure. At figure 302, the method 300 receives a handwheel angle signal from a sensor associated with a handwheel of a vehicle. For example, the control unit 100 can receive the handwheel angle signal from the sensor 106 associated with the handwheel of the vehicle 10.

[0059] In 304, the method 300 generates a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal. For example, the control unit 100 can generate the handwheel speed signal and the handwheel acceleration signal based on the handwheel angle indicated by the handwheel angle signal.

[0060] In 306, method 300 synchronizes the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal. For example, the control unit 100 can synchronize the handwheel speed signal and the handwheel acceleration signal by generating the delayed handwheel speed signal and the delayed handwheel acceleration signal.

[0061] In the case of 308, the method 300 generates a driver torque estimation signal that is based at least on the delayed handwheel speed signal and the delayed handwheel acceleration signal. For example, the control unit 100 can generate the driver torque estimation signal based at least on the delayed handwheel speed signal and the delayed handwheel acceleration signal.

[0062] In the case of 310, procedure 300 determines, based on the driver torque estimation signal, whether the driver's hands are on the handwheel. For example, control unit 100 can determine, based on the driver torque signal, whether a driver's hands are on the handwheel.

[0063] In some embodiments, a method for detecting hands on the steering wheel comprises receiving a handwheel angle signal from a sensor associated with a vehicle's handwheel and generating a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal. The method also includes synchronizing the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal. The method further includes generating a driver torque estimate signal based at least on the delayed handwheel speed signal and the delayed handwheel acceleration signal. Finally, the method includes determining whether a vehicle driver's hands are on the handwheel based on the driver torque estimate signal.

[0064] In some embodiments, the handwheel is associated with an electric power steering system of the vehicle. In some cases, the handwheel is associated with a hydraulic steering system of the vehicle. In some embodiments, the hydraulic steering system includes a magnetic actuator integrated into a valve assembly of the hydraulic steering system. In some embodiments, generating the driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal includes: calculating a damping value by determining a product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value;Calculating an inertia value by determining the product of a handwheel acceleration value, indicated by the delayed handwheel acceleration signal, and a handwheel inertia scale value; calculating a friction value by determining the product of a friction direction signal and a friction magnitude scale value; generating a delayed valve torque signal by delaying a received valve torque signal; and generating the driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed valve torque signal.

[0065] In some embodiments, a method for detecting hands on the steering wheel comprises receiving a handwheel angle signal from a sensor associated with a vehicle's handwheel and generating a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal. The method also comprises synchronizing the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal, and generating a driver torque estimate signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal. The method also includes determining whether a vehicle driver's hands are on the handwheel based on the driver torque estimate signal.

[0066] In some embodiments, the handwheel is associated with an electric power steering system of the vehicle. In some embodiments, the handwheel is associated with a hydraulic steering system of the vehicle. In some embodiments, the hydraulic steering system includes a magnetic actuator integrated into a valve assembly of the hydraulic steering system. In some embodiments, the method also includes: calculating a damping value by determining the product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value; and calculating an inertia value by determining the product of a handwheel acceleration value indicated by the delayed handwheel acceleration signal and a handwheel inertia scale value.In some embodiments, the method also includes: calculating a friction value by determining the product of a friction direction signal and a friction magnitude scale value; and generating a delayed valve torque signal by delaying a received valve torque signal. In some embodiments, generating the driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal includes generating the driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed received valve torque signal. In some embodiments, the sensor associated with the vehicle's handwheel includes a handwheel position sensor.

[0067] In some embodiments, a system for detecting hands on the steering wheel includes a processor and memory.The memory contains instructions which, when executed by the processor, cause the processor to: receive a handwheel angle signal from a sensor associated with a vehicle's handwheel; generate a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; generate a driver torque estimate signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal; and determine whether the hands of a vehicle's driver are on the handwheel based on the driver torque estimate signal.

[0068] In some embodiments, the handwheel is associated with the vehicle's electric power steering system. In some embodiments, the handwheel is associated with the vehicle's hydraulic steering system. In some embodiments, the hydraulic steering system includes a magnetic actuator integrated into a valve assembly of the hydraulic steering system. In some embodiments, the instructions also cause the processor to: calculate a damping value by determining the product of a handwheel velocity value, indicated by the delayed handwheel velocity signal, and a damping coefficient scale value; and calculate an inertia value by determining the product of a handwheel acceleration value, indicated by the delayed handwheel acceleration signal, and a handwheel inertia scale value.In some embodiments, the instructions also cause the processor to: calculate a friction value by determining the product of a friction direction signal and a friction magnitude scale value; and generate a delayed valve torque signal by delaying a received valve torque signal. In some embodiments, the instructions also cause the processor to generate the driver torque estimate signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal by generating the driver torque estimate signal based on the damping value, the inertia value, the friction value, and the delayed received valve torque signal. In some embodiments, the sensor associated with the vehicle's handwheel includes a handwheel position sensor.

[0069] In some embodiments, a device for detecting hands on the steering wheel includes a processor and a memory. The memory contains instructions which, when executed by the processor, cause the processor to: receive a handwheel angle signal from a sensor associated with a vehicle's handwheel; generate a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; calculate a damping value by determining the product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value;to calculate an inertia value by determining the product of a handwheel acceleration value indicated by the delayed handwheel acceleration signal and a handwheel inertia scale value; to calculate a friction value by determining the product of a friction direction signal and a friction magnitude scale value; to generate a delayed valve torque signal by delaying a received valve torque signal; to generate a driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed received valve torque signal; and to determine whether the hands of a driver of the vehicle are on the handwheel, based on the driver torque estimation signal.

[0070] In some embodiments, the handwheel is associated with the vehicle's electric power steering system. In some embodiments, the handwheel is associated with the vehicle's hydraulic steering system. In some embodiments, the hydraulic steering system includes a magnetic actuator integrated into a valve assembly of the hydraulic steering system.

[0071] The foregoing is intended to illustrate the principles and various embodiments of the present invention. Numerous variations and modifications will be obvious to the person skilled in the art once the foregoing disclosure is fully understood. It is intended that the following claims be interpreted to encompass all such variations and modifications.

[0072] The word "example" is used here to serve as an example, instance, or illustration. Each aspect or design described herein as an "example" is not necessarily to be interpreted as being preferred or advantageous over other aspects or designs. Rather, the use of the word "example" is intended to illustrate concepts in a concrete way. As used in this application, the term "or" is intended to mean an inclusive "or" and not an exclusive "or." That is to say, unless otherwise stated or evident from the context, "X includes A or B" means each of the natural inclusive permutations. That is to say, if X includes A, X includes B, or X includes both A and B, then "X includes A or B" is satisfied in each of the aforementioned cases.Furthermore, the articles “one / an” as used in this application and the attached claims are generally to be interpreted as meaning “one or more”, unless otherwise specified or it is clear from the context that they refer to a singular form. Moreover, the use of the term “an implementation” or “the one implementation” is not synonymous with the same embodiment or implementation unless described as such.

[0073] Implementations of the systems, algorithms, procedures, instructions, etc., described herein may be realized in hardware, software, or any combination thereof. The hardware may include, for example, computers, intellectual property (IP) cores, application-specific integrated circuits (ASICs), programmable logic arrays, optical processors, programmable logic controllers, microcode, microcontrollers, servers, microprocessors, digital signal processors, or any other suitable circuitry. In the claims, the term "processor" is to be understood as encompassing any of the aforementioned hardware components, either individually or in combination. The terms "signal" and "data" are used interchangeably.

[0074] As used herein, the term module can encompass a packaged functional hardware unit designed for use with other components, a set of instructions that can be executed by a control device (such as a processor running software or firmware), processing circuitry configured to perform a specific function, and a self-contained hardware or software component that provides an interface to a larger system. For example, a module might include an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a circuit, a digital logic circuit, an analog circuit, a combination of discrete circuits, gates, and other types of hardware, or a combination thereof.In other embodiments, a module may contain a memory in which instructions are stored that can be executed by a control unit to implement a feature of the module.

[0075] In one aspect, the systems described here can be implemented, for example, with a general-purpose computer or a general-purpose processor running a computer program that executes the procedures, algorithms, and / or instructions described here. Additionally or alternatively, a specialized computer / processor can be used, which may contain other hardware for executing the procedures, algorithms, or instructions described here.

[0076] Furthermore, all or part of the implementations of the present disclosure may take the form of a computer program product accessible, for example, from a computer-usable or computer-readable medium. A computer-usable or computer-readable medium may be any device that can, for example, specifically contain, store, transmit, or transport the program for use by or in conjunction with any processor. The medium may, for example, be an electronic, magnetic, optical, electromagnetic, or semiconductor device. Other suitable media are also available.

Claims

[1] Method for detecting hands on the steering wheel, the method comprising: Receiving a handwheel angle signal from a sensor (106) associated with a handwheel of a vehicle; Generating a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; Synchronizing the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; Generating a driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal; and Determine whether the vehicle driver's hands are on the handwheel, based on the driver torque estimation signal. [2] Method according to claim 1, characterized bythat the handwheel is associated with the vehicle's electric power steering. [3] Method according to claim 1, characterized by that the handwheel is assigned to a hydraulic steering system of the vehicle. [4] Method according to claim 3, characterized by that the hydraulic steering system includes a magnetic actuator which is integrated into a valve assembly of the hydraulic steering system. [5] Method according to claim 3, characterized by , that the procedure further includes: Calculating a damping value by determining the product of a handwheel speed value, indicated by the delayed handwheel speed signal, and a damping coefficient scale value; and Calculating an inertia value by determining the product of a handwheel acceleration value indicated by the delayed handwheel acceleration signal and a handwheel inertia scale value. [6] Method according to claim 5, characterized by , that the procedure further includes: Calculating a friction value by determining the product of a friction direction signal and a friction scale value; and Generating a delayed valve torque signal by delaying a received valve torque signal. [7] Method according to claim 6, characterized by , that generating the driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal includes generating the driver torque estimation signal based on the damping value, the inertia value, the friction value and the delayed received valve torque signal. [8] Method according to claim 1, characterized by , that the sensor (106) associated with the vehicle's handwheel includes a handwheel position sensor. [9] Hands-on-steerage detection system, comprising: a processor (102); and a memory (104) containing instructions which, when executed by the processor (102), cause the processor (102) to: to receive a handwheel angle signal from a sensor (106) associated with a handwheel of a vehicle; to generate a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; to synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; to generate a driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal; and to determine, based on the driver torque estimation signal, whether the hands of a driver of the vehicle are on the handwheel. [10] System according to claim 9, characterized by that the handwheel is associated with an electric power steering system of the vehicle. [11] System according to claim 9, characterized by that the handwheel is assigned to a hydraulic steering system of the vehicle. [12] System according to claim 11, characterized by that the hydraulic steering system includes a magnetic actuator which is integrated into a valve assembly of the hydraulic steering system. [13] System according to claim 11, characterized by , that the instructions also cause the processor (102) to: to calculate a damping value by determining the product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value; and to calculate an inertia value by determining a product of a handwheel acceleration value indicated by the delayed handwheel acceleration signal and a handwheel inertia scale value. [14] System according to claim 13, characterized by , that the instructions also cause the processor (102) to: to calculate a friction value by determining the product of a friction direction signal and a friction scale value; and To generate a delayed valve torque signal by delaying a received valve torque signal. [15] System according to claim 14, characterized by, that the instructions further cause the processor (102) to generate the driver torque estimation signal based on at least the delayed handwheel speed signal and the delayed handwheel acceleration signal by generating the driver torque estimation signal based on the damping value, the inertia value, the friction value and the delayed received valve torque signal. [16] System according to claim 9, characterized by , that the sensor (106) associated with the vehicle's handwheel includes a handwheel position sensor. [17] Device for detecting hands on the steering wheel, the device comprising: a processor (102); and a memory (104) containing instructions which, when executed by the processor (102), cause the processor (102) to: to receive a handwheel angle signal from a sensor (106) associated with a handwheel of a vehicle; to generate a handwheel speed signal and a handwheel acceleration signal based on a handwheel angle indicated by the handwheel angle signal; to synchronize the handwheel speed signal and the handwheel acceleration signal by generating a delayed handwheel speed signal and a delayed handwheel acceleration signal; to calculate a damping value by determining a product of a handwheel speed value indicated by the delayed handwheel speed signal and a damping coefficient scale value; to calculate an inertia value by determining a product of a handwheel acceleration value indicated by the delayed handwheel acceleration signal and a handwheel inertia scale value; to calculate a friction value by determining a product of a friction direction signal and a friction scale value; to generate a delayed valve torque signal by delaying a received valve torque signal; to generate a driver torque estimation signal based on the damping value, the inertia value, the friction value, and the delayed received valve torque signal; and to determine, based on the driver torque estimation signal, whether the driver's hands are on the handwheel. [18] Device according to claim 17, characterized by that the handwheel is assigned to a hydraulic steering system of the vehicle. [19] Device according to claim 18, characterized by that the hydraulic steering system contains a magnetic actuator which is integrated into a valve assembly of the hydraulic steering system.

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