Angle and torque measuring system of electronic power steering system

Abstract

The invention discloses an angle and torque measuring system of an electronic power-assisted steering system, which belongs to the technical field of electronic power-assisted steering systems and comprises a sensor component module, a component parameter acquisition module, a steering wheel angle initial absolute position calculation module and a steering wheel and steering column absolute angle calculation module. A steering wheel and steering column virtual rotation angle calculation module; and a torque calculation module. The angle and torque of the electronic power-assisted steering system can be measured only by combining the steering wheel angle sensor with the rotor position sensor of the original electronic power-assisted motor, the structure is simplified, the hardware cost is reduced, and meanwhile the installation process is simplified.

Description

Technical Field

[0001] This invention belongs to the technical field of electronic power steering systems, specifically relating to an angle and torque measurement system for electronic power steering systems. Background Technology

[0002] Electronic power steering system refers to a car steering assistance system that uses an electronic control unit as its core and an electric motor as its power source to replace the traditional hydraulic power steering.

[0003] The electronic power steering system collects the driver's steering intentions, including steering angle and steering torque, as well as vehicle driving conditions, including vehicle speed and engine speed, in real time. The electronic control unit dynamically calculates and controls the power steering motor to output the corresponding torque according to a preset algorithm, assisting the driver in completing the steering operation and achieving an adaptive power steering effect of "light steering at low speeds and stable steering at high speeds".

[0004] The typical methods for calculating the steering angle and steering torque of current electronic power steering systems are shown in the appendix. Figure 1 As shown, the input shaft is connected to the upper rotor and drives a permanent magnet via gears. The upper rotor is surrounded by multiple sets of induction coils. When the steering wheel is turned, the input shaft drives the upper rotor and permanent magnet to rotate. The magnetic field direction of the permanent magnet changes with the rotation angle, allowing for the detection of angle signals. Simultaneously, the rotation of the upper rotor causes the magnetic field of the induction coils to change periodically, inducing an alternating electrical signal. The phase and amplitude of this signal correspond to the absolute angle of the upper rotor. The sensor converts the analog electrical signal into a position signal and outputs it to the electronic control unit. The electronic control unit calculates the absolute rotation angle of the input shaft. The output shaft is connected to the lower rotor, which is symmetrically arranged with the upper rotor and shares the same configuration. Multiple sets of induction coils are used. The output shaft rotates with the steering mechanism, driving the lower rotor to rotate. This also causes the induction coils to generate alternating electrical signals. The phase and amplitude of these signals correspond to the angle of the lower rotor. The sensor converts the analog electrical signals into position signals and outputs them to the electronic control unit. The electronic control unit calculates the rotation angle of the output shaft. A torsion bar is elastically connected between the input and output shafts. When steering, the speed difference between the input and output shafts causes the torsion bar to twist. The upper and lower induction coils have a signal difference. The sensor converts the analog electrical signals into torque signals and outputs them to the electronic control unit. The electronic control unit calculates the torsion angle to obtain the steering torque.

[0005] The above-mentioned methods for acquiring steering angle and steering torque of electronic power steering systems have the following problems: acquiring steering angle and steering torque requires measuring angle signals at three different positions, which leads to cumbersome processes and increases hardware costs. In addition, the acquisition devices have different rotary shaft input interfaces, making the installation process complicated.

[0006] Therefore, an angle and torque measurement system for electronic power steering systems is designed to solve the above problems. Summary of the Invention

[0007] To address the problems mentioned in the background section, this invention provides an angle and torque measurement system for an electronic power steering system, which features a simplified structure, reduced hardware costs, and simplified installation process.

[0008] To achieve the above objectives, the present invention provides the following technical solution: an angle and torque measurement system for an electronic power steering system, comprising:

[0009] The sensor component module includes a steering wheel angle sensor mounted on the steering wheel and an electronic power steering motor with a built-in rotor position sensor mounted on the steering column via a reduction mechanism. There is a speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft, and there is a speed ratio between the worm gear and worm of the reduction mechanism.

[0010] The component parameter acquisition module obtains the torsion bar torque elastic coefficient.

[0011] The initial absolute position calculation module for steering wheel angle calculates the initial absolute position of the steering wheel angle at power-on when the torsion bar torque is zero. At this time, the steering wheel angle is the same as the steering column angle. The steering wheel angle sensor measures the relative angle of the steering wheel, and the rotor position sensor measures the rotor angle of the electronic power steering motor. Based on the measured relative angle, rotor angle, speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft, and speed ratio between the worm gear and worm wheel of the reduction mechanism, the vernier algorithm calculates the initial absolute position of the steering wheel angle.

[0012] The steering wheel and steering column absolute angle calculation module calculates the steering wheel and steering column absolute angles after the initial absolute position of the steering wheel angle is determined. The steering wheel angle sensor measures the relative angle of the steering wheel, and the rotor position sensor measures the rotor angle of the electronic power steering motor. It calculates the angle difference between the measured relative angle of the steering wheel and the relative angle of the steering wheel at the moment of power-on, as well as the angle difference between the measured rotor angle and the rotor angle at the moment of power-on. The absolute angle of the steering wheel and the absolute angle of the steering column are calculated by using the initial absolute position of the steering wheel angle, the angle difference between the measured relative angle of the steering wheel and the relative angle of the steering wheel at the moment of power-on, the angle difference between the measured rotor angle and the rotor angle at the moment of power-on, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft, and the speed ratio between the worm gear and the reduction mechanism.

[0013] The virtual steering wheel and steering column angle calculation module calculates the virtual steering wheel angle and the virtual steering column angle by means of the initial absolute position of the steering wheel angle, the difference between the measured relative steering wheel angle and the relative steering wheel angle at the time of power-on, the difference between the measured rotor angle and the rotor angle at the time of power-on, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft, and the speed ratio between the worm gear and the reduction mechanism.

[0014] The steering wheel torque calculation module calculates the steering wheel torque using the virtual steering wheel angle, the virtual steering column angle, and the torsion bar torque elastic coefficient.

[0015] Furthermore, in the sensor component module, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism satisfy the condition that the number of revolutions between the steering wheel angle sensor and the electronic power steering motor are coprime.

[0016] Furthermore, in the sensor component module, the angle output signals of the steering wheel angle sensor and the rotor position sensor are greater than or equal to one signal.

[0017] Furthermore, in the steering wheel angle initial absolute position calculation module, the expression for calculating the initial absolute position of the steering wheel angle is:

[0018] θ key on =f(γ) key on / r1,δ key on / r2)

[0019] In the formula: γ key on The angle measured by the steering wheel angle sensor at the moment of power-on is indicated; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft; δ key on r1 represents the rotor angle at the moment of power-on; r2 represents the speed ratio of the worm gear in the reduction mechanism; f() function is a vernier algorithm for calculating the absolute angle using two coprime relative angles.

[0020] Furthermore, in the absolute steering wheel and steering column angle calculation module, the expression for calculating the absolute steering wheel angle is:

[0021] θ 方向盘 =θ key on +Δγ / r1

[0022] In the formula: θ key on Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

[0023] Furthermore, in the absolute steering column angle calculation module, the expression for calculating the absolute steering column angle is:

[0024] θ 转向柱 =θ key on +Δδ / r2

[0025] In the formula: θ keyon Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

[0026] Furthermore, in the steering wheel and steering column virtual angle calculation module, the calculation expression for the steering wheel virtual angle is:

[0027] α = MOD(θ) keyon +Δγ / r1,360)

[0028] In the formula: θ key on Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

[0029] Furthermore, in the steering wheel and steering column virtual angle calculation module, the calculation expression for the steering column virtual angle is:

[0030] β=MOD(θ keyon +Δδ / r2,360)

[0031] In the formula: θ key on Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

[0032] Furthermore, in the steering wheel torque calculation module, the expression for calculating the steering wheel torque is:

[0033] T = k*(α - β)

[0034] In the formula: α represents the virtual steering wheel angle; β represents the virtual steering column angle; k represents the torsion bar torque coefficient.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] 1. The present invention can measure the angle and torque of the electronic power steering system by simply using a steering wheel angle sensor in combination with the rotor position sensor of the original electronic power steering motor, which simplifies the structure, reduces hardware costs, and simplifies the installation process.

[0037] 2. Both the steering wheel angle sensor and the rotor position sensor of this invention are designed to output multiple sensor signal channels, which improves the functional safety level without affecting the simplification of the structure.

[0038] 3. The present invention does not limit the speed ratio between the steering wheel angle sensor and the steering wheel and the speed ratio between the worm gear and the reduction mechanism. It only needs to meet the condition that the number of revolutions between the steering wheel angle sensor and the electronic power steering motor are coprime. It has a wide range of applications.

[0039] 4. This invention can span multiple cycles and improve measurement accuracy. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the existing system principle;

[0041] Figure 2 This is a schematic diagram of the system installation structure of the present invention;

[0042] Figure 3 This is a schematic diagram illustrating the results of an example of the present invention;

[0043] In the diagram: 1. Sensor component module; 2. Component parameter acquisition module; 3. Steering wheel angle initial absolute position calculation module; 4. Steering wheel and steering column absolute angle calculation module; 5. Steering wheel and steering column virtual angle calculation module; 6. Steering wheel torque calculation module. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] See appendix Figure 2 An angle and torque measurement system for an electronic power steering system, comprising:

[0046] Sensor component module 1 includes a steering wheel angle sensor installed on the steering wheel and an electronic power steering motor with a built-in rotor position sensor installed on the steering column via a reduction mechanism. There is a speed ratio r1 between the steering wheel angle sensor shaft and the steering wheel shaft, and a speed ratio r2 between the worm gear and the reduction mechanism.

[0047] Component parameter acquisition module 2, acquires the torsion bar torque elastic coefficient k;

[0048] Steering wheel angle initial absolute position calculation module 3: At power-on, the torsion bar torque is zero, and at this time the steering wheel angle α key on With steering column angle βkey on Similarly, the steering wheel angle sensor measures the relative angle γ of the steering wheel. key on The rotor position sensor measures the rotor angle δ of the electronically assisted motor. key on The vernier algorithm is based on the measured relative angle γ key on Rotor angle δ key on The initial absolute position θ of the steering wheel angle is calculated by the speed ratio r1 between the steering wheel angle sensor shaft and the steering wheel shaft, and the speed ratio r2 between the worm gear and the reduction mechanism. key on ;

[0049] Steering wheel and steering column absolute angle calculation module 4, initial absolute position θ of steering wheel angle. key on Once determined, the steering wheel angle sensor measures the relative steering wheel angle γ, and the rotor position sensor measures the rotor angle δ of the electronic power steering motor. The measured relative steering wheel angle γ is then compared to the relative steering wheel angle γ at the moment of power-on. key on The angle difference Δγ, and the measured rotor angle δ compared with the rotor angle δ at the moment of power-on. key on The angle difference Δδ is determined by the initial absolute position θ of the steering wheel angle. key on Measure the relative steering wheel angle γ and the relative steering wheel angle γ at the moment of power-on. key on Angle difference Δγ, measured rotor angle δ and rotor angle δ at power-on time key on The absolute steering angle θ is calculated from the angle difference Δδ, the speed ratio r1 between the steering wheel angle sensor shaft and the steering wheel shaft, and the speed ratio r2 between the worm gear and the reduction mechanism. 方向盘 and the absolute steering column angle θ 转向 column;

[0050] The steering wheel and steering column virtual angle calculation module 5 calculates the initial absolute position θ of the steering wheel angle. keyon Measure the relative steering wheel angle γ and the relative steering wheel angle γ at the moment of power-on. key on Angle difference Δγ, measured rotor angle δ and rotor angle δ at power-on time key on The angle difference Δδ, the speed ratio r1 between the steering wheel angle sensor shaft and the steering wheel shaft, and the speed ratio r2 between the worm gear and the reduction mechanism are used to calculate the virtual steering wheel angle α and the virtual steering column angle β, respectively.

[0051] The steering wheel torque calculation module 6 calculates the steering wheel torque using the virtual steering wheel angle α, the virtual steering column angle β, and the torsion bar torque elastic coefficient k.

[0052] Specifically, in sensor component module 1, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism satisfy the condition that the number of revolutions between the steering wheel angle sensor and the electronic power steering motor are coprime.

[0053] The steering wheel angle sensor shaft and the steering wheel shaft can be installed coaxially or non-coaxially. If the steering wheel angle sensor shaft and the steering wheel shaft are installed coaxially, then r1 = 1. If the steering wheel angle sensor shaft and the steering wheel shaft are not installed coaxially, then r1 ≠ 1.

[0054] The number of worm threads and the number of worm teeth in the worm gear of the reduction mechanism can be changed;

[0055] See appendix Figure 3 Assuming the worm gear ratio of the reduction mechanism of the electronic power steering system is r2 = 21, and the number of turns required to detect the absolute position of the steering wheel angle is more than 3 turns, designed as 3.33 turns, then the corresponding number of turns of the electronic power steering motor is 70 turns.

[0056] In order to meet the requirement of being able to be calculated by the vernier algorithm, the number of revolutions of the steering wheel angle sensor and the 70 revolutions of the electronic power steering motor must be coprime, and it is designed to be 69 revolutions;

[0057] Based on the steering wheel angle sensor's rotation count of 69, the steering wheel detection count of 3.33, and the steering wheel angle sensor's pole pair count of 18, the speed ratio r1 between the steering wheel angle sensor shaft and the steering wheel shaft is obtained as 20:23 (or 40:46).

[0058] That is, within a steering wheel rotation of 3.33 turns, the steering wheel angle sensor outputs 69 cycles of signal, and the electronic power steering motor rotor position sensor outputs 70 cycles of signal, which has a vernier relationship;

[0059] The 69 circles mentioned above are not the only possible values; they only need to satisfy the coprime relationship.

[0060] The 18 pole pairs mentioned above are not unique pole pairs; any pole pair can be used.

[0061] If the number of worm wheel threads in the reduction mechanism is ≥3, and the number of worm wheel teeth and the number of worm threads are coprime, then the number of worm threads is the absolute number of turns that the steering wheel can recognize. In this case, r1 can be set to 1 to simplify the design of the steering wheel angle sensor.

[0062] Specifically, in sensor component module 1, the angle output signals of the steering wheel angle sensor and the rotor position sensor are greater than or equal to one signal.

[0063] Specifically, in the steering wheel angle initial absolute position calculation module 3, the expression for calculating the initial absolute position of the steering wheel angle is as follows:

[0064] θ key on =f(γ) key on / r1,δ key on / r2)

[0065] In the formula: γ key on The angle measured by the steering wheel angle sensor at the moment of power-on is indicated; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft; δ key on r1 represents the rotor angle at the moment of power-on; r2 represents the speed ratio of the worm gear in the reduction mechanism; f() function is a vernier algorithm for calculating the absolute angle using two coprime relative angles.

[0066] Specifically, in the steering wheel and steering column absolute angle calculation module 4, the expression for calculating the steering wheel absolute angle is:

[0067] θ 方向盘 =θ key on +Δγ / r1

[0068] In the formula: θ key on Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

[0069] Specifically, in the steering wheel and steering column absolute angle calculation module 4, the expression for calculating the steering column absolute angle is as follows:

[0070] θ 转向柱 =θ key on +Δδ / r2

[0071] In the formula: θ key on Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

[0072] Specifically, in the steering wheel and steering column virtual angle calculation module 5, the calculation expression for the steering wheel virtual angle is as follows:

[0073] α = MOD(θ)keyon +Δγ / r1,360)

[0074] In the formula: θ key on Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

[0075] Specifically, in the steering wheel and steering column virtual angle calculation module 5, the calculation expression for the steering column virtual angle is as follows:

[0076] β=MOD(θ keyon +Δδ / r2,360)

[0077] In the formula: θ key on Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

[0078] Specifically, in the steering wheel torque calculation module 6, the expression for calculating the steering wheel torque is as follows:

[0079] T = k*(α - β)

[0080] In the formula: α represents the virtual steering wheel angle; β represents the virtual steering column angle; k represents the torsion bar torque coefficient.

[0081] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An angle and torque measurement system for an electronic power steering system, characterized in that, include: The sensor component module (1) has a steering wheel angle sensor installed on the steering wheel and an electronic power steering motor with its own rotor position sensor installed on the steering column through a reduction mechanism. There is a speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft, and there is a speed ratio between the worm gear and the worm of the reduction mechanism. Component parameter acquisition module (2) acquires the torsion bar torque elastic coefficient; The initial absolute position calculation module for steering wheel angle (3) measures the relative angle of the steering wheel and the rotor position sensor respectively at the moment of power-on. The vernier algorithm calculates the initial absolute position of the steering wheel angle by using the relative angle of the steering wheel, the rotor angle, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism. The steering wheel and steering column absolute angle calculation module (4) continues to measure the relative angle of the steering wheel and the rotor position sensor of the electronic power assist motor, and calculates the angle difference between the relative angle of the steering wheel and the rotor angle of the electronic power assist motor at the moment of power-on. The absolute angle of the steering wheel and the absolute angle of the steering column are calculated by the initial absolute position of the steering wheel angle, the two angle differences, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism. The steering wheel and steering column virtual angle calculation module (5) calculates the virtual steering wheel angle and the virtual steering column angle by using the initial absolute position of the steering wheel angle, the difference between the two angles, the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism respectively. The steering wheel torque calculation module (6) calculates the steering wheel torque by using the virtual steering wheel angle, the virtual steering column angle, and the torsion bar torque elastic coefficient.

2. The angle and torque measurement system for an electronic power steering system according to claim 1, characterized in that: In the sensor component module (1), the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft and the speed ratio between the worm gear and the reduction mechanism satisfy the condition that the number of revolutions between the steering wheel angle sensor and the electronic power assist motor are coprime.

3. The angle and torque measurement system for an electronic power steering system according to claim 2, characterized in that: In the sensor component module (1), the angle output signals of the steering wheel angle sensor and the rotor position sensor are greater than or equal to one signal.

4. The angle and torque measurement system for an electronic power steering system according to claim 3, characterized in that: In the steering wheel angle initial absolute position calculation module (3), the expression for calculating the initial absolute position of the steering wheel angle is: i keyon =f(γ keyon / r1,δ keyon / r2) In the formula: γ keyon The angle measured by the steering wheel angle sensor at the moment of power-on is indicated; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft; δ keyon r1 represents the rotor angle at the moment of power-on; r2 represents the speed ratio of the worm gear in the reduction mechanism; f() function is a vernier algorithm for calculating the absolute angle using two coprime relative angles.

5. The angle and torque measurement system for an electronic power steering system according to claim 4, characterized in that: In the absolute steering wheel and steering column angle calculation module (4), the expression for calculating the absolute steering wheel angle is: i 方向盘 =θ keyon +Δγ / r1 In the formula: θ keyon Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

6. The angle and torque measurement system for an electronic power steering system according to claim 5, characterized in that: In the absolute steering column angle calculation module (4), the expression for calculating the absolute steering column angle is: i 转向柱 =θ keyon +Δδ / r2 In the formula: θ keyon Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

7. The angle and torque measurement system for an electronic power steering system according to claim 6, characterized in that: In the steering wheel and steering column virtual angle calculation module (5), the calculation expression for the steering wheel virtual angle is: α=MOD(θ keyon +Δγ / r1.360) In the formula: θ keyon Δγ represents the initial absolute position of the steering wheel angle; Δγ represents the angle difference measured by the steering wheel angle sensor between the current moment and the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r1 represents the speed ratio between the steering wheel angle sensor shaft and the steering wheel shaft.

8. The angle and torque measurement system for an electronic power steering system according to claim 7, characterized in that: In the steering wheel and steering column virtual angle calculation module (5), the calculation expression for the steering column virtual angle is: β=MOD(θ keyon +Δδ / r2,360) In the formula: θ keyon Δδ represents the initial absolute position of the steering wheel angle; Δδ represents the angle difference between the rotor angle of the electronic power steering motor at the current moment and at the moment of power-on. If the measured angle spans a cycle, the angle spanned by the cycle must be included; r2 represents the speed ratio of the worm gear in the reduction mechanism.

9. The angle and torque measurement system for an electronic power steering system according to claim 8, characterized in that: In the steering wheel torque calculation module (6), the expression for calculating the steering wheel torque is: T = k*(α - β) In the formula: α represents the virtual steering wheel angle; β represents the virtual steering column angle; k represents the torsion bar torque coefficient.

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