Method for diagnosing an automotive electric brake system - Patents.com

Abstract

The present invention relates to a method for diagnosing a vehicle electric brake system, the vehicle comprising such vehicle electric brake system, a controller configured to diagnose the vehicle electric brake system, and a computer program for diagnosing the vehicle electric brake system. The method comprises the steps of generating a test current value and an expected brake effect value, commanding a brake power source of the electric brake system to supply a test current to an electric brake motor of the electric brake system, receiving a brake effect measurement from a sensor of the vehicle, and obtaining a diagnostic result by comparing the brake effect measurement to the expected brake effect value. Optionally, the brake effect comprises an increase in power supplied from a wheel motor power source to an electric wheel motor, such as an in-wheel motor, of the vehicle.

Description

[Technical Field]

[0001] The present invention relates to a vehicle. electronic Method for diagnosing a brake system and such a vehicle electronic Brake system of the vehicle electronic Controller configured to perform steps of a method for diagnosing a brake system, and motor vehicle electronic The present invention relates to a motor vehicle equipped with a computer program for diagnosing the braking system. [Background technology]

[0002] A common type of braking system for a wheel of an automobile includes a brake disc that rotates with the wheel and brake pads that press against the brake disc during braking, creating friction between the brake pads and the brake disc, which in turn creates a braking force that slows the wheel associated with the brake disc.

[0003] electronic In a braking system, brake pads are driven toward the brake disc during braking and away from the brake disc after braking by an electric brake motor. The electric brake motor is mechanically connected to the brake pads, for example, using a spindle / ball screw, which is rotationally driven by a motor, causing linear movement of the brake pads toward or away from the brake disc. To drive the electric brake motor, the electric brake motor receives current from a brake power source, typically the vehicle's battery.

[0004] The braking action is the result of a braking request, which may be executed by the driver of the vehicle when the driver presses the brake pedal of the vehicle, or in another example, the braking request may be executed by an automated system of the vehicle. electronicThe braking system converts the required braking force into an appropriate current value, and then requests a current of a magnitude equal to the calculated current value to be supplied from the brake power supply to the electric brake motor. Thus, the calculated current value is proportional to the required braking force of the braking action. However, in some cases, the effect of the braking action, i.e., the actual deceleration of the vehicle, differs from the expected effect of the braking action, i.e., the expected deceleration of the vehicle. This can occur, for example, due to the presence of various components in the brake pads, spindles, electric brake motors, etc. electronic This can occur due to wear and tear on braking system components. Such a malfunction of the braking system can lead to a dangerous situation if the braking force generated is reduced to the point where the vehicle cannot stop quickly enough. If the vehicle has multiple wheels, each associated with a brake, the vehicle will be more likely to pull in one direction when braking if one brake is not functioning. It is therefore of utmost importance that such malfunctions are detected before an unsafe situation occurs.

[0005] Many diagnostic methods and systems have been proposed in the art to detect whether a vehicle's braking system is functioning properly. For example, when the vehicle is stationary, the brakes are applied, and the resulting force generated by the interaction of the brake pads with the associated brake discs is measured and compared to an expected braking force. However, such methods do not measure the effectiveness of the braking operation while the vehicle is moving. As a result, existing methods cannot accurately determine whether the effectiveness of the braking operation corresponds to the expected effectiveness of the braking operation. EP 3888983 A1 discloses a brake control unit including a primary control branch and a backup control branch, each configured to generate a brake mode drive signal in response to an external brake control signal. The control module is configured to diagnose the integrity status of the backup control branch by verifying a response signal of the backup control branch in response to a test signal. The test signal may be, for example, an external brake control signal. If the signal generated by the brake control branch significantly deviates from the corresponding signal of the primary control branch, it is determined that the integrity of the backup control branch has been lost. The response signal compared may, for example, represent a control signal provided by the backup control module to a backup inverter. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention relates to a vehicle electronic An object of the present invention is to provide an improved method for diagnosing a brake system. [Means for solving the problem]

[0007] This object of the invention is to provide a method for detecting the movement of a vehicle while at least one wheel of the vehicle is being driven. electronic This is achieved by a method for diagnosing a brake system, the method comprising: generating a test current value and an expected braking effect value, the expected braking effect value being inferred from the test current value based on vehicle characteristics; Test current electronic To supply the electric brake motor of the braking system, electronic configured to drive an electric brake motor of a braking system electronic commanding a brake power supply of the brake system, the magnitude of the test current being equal to the test current value; receiving a brake effectiveness measurement from a sensor on the vehicle, the brake effectiveness measurement comprising: electronic It describes the effect on a vehicle as a result of the braking force generated by the interaction of the brake discs and brake pads of a braking system, and the interaction between the brake discs and brake pads is such that the brake pads electronic a brake disc being pressed against the brake disc by an electric brake motor of the braking system, the brake disc being associated with a wheel of the vehicle; and obtaining a diagnostic result by comparing the measured braking effectiveness value with an expected braking effectiveness value.

[0008] The method according to the present invention is electronicThe method is performed to diagnose a brake system. The vehicle has at least one wheel. For example, the vehicle has two wheels, four wheels, or eight wheels. The method is performed while at least one wheel of the vehicle is driven by a prime mover. For example, at least one wheel is driven by the vehicle's centralized prime mover. The centralized prime mover is, for example, an internal combustion engine driven by the combustion of fuel or an electric motor driven by a supply of current from a power source such as a battery. In another example, the wheel is driven by an electric in-wheel motor. The in-wheel motor directly drives the associated wheel and is driven by a supply of current from a power source such as a battery. Driving the wheel causes the wheel to rotate, thereby propelling the vehicle across a surface, such as a road, at a certain speed when the vehicle is positioned on that surface. The vehicle may remain stationary while the wheels are rotating, for example, when the vehicle is undergoing inspection and is positioned on a test bed with rollers for the vehicle's wheels, or when the vehicle is suspended in the air by a lifting device that does not engage the vehicle's wheels.

[0009] Automotive electronic Brake systems include brake pads and brake discs. The brake discs are typically mechanically attached to each wheel of the vehicle, thereby following the rotation of the associated wheel. The brake pads are typically held in brake calipers that are positioned such that the brake pads are spaced apart from the brake discs when no braking action is being performed. electronicThe braking system further includes an electric brake motor and an electric brake power supply. When a braking operation is performed, an electric current is supplied from the electric brake power supply to the electric brake motor, thereby driving the electric brake motor. The electric brake motor is further mechanically connected to a brake actuator, such as a spindle and / or a piston. The electric brake motor drives the brake actuator to move the brake pads, which move toward and contact the brake disc. The interaction between the brake pads and the brake disc generates a frictional force. This frictional force reduces the rotational or angular velocity of the wheels. As the vehicle travels over a surface, it decelerates, i.e., the vehicle's speed decreases.

[0010] Automotive electronic To diagnose whether the brake system is functioning properly, a test current value is first generated. The test current value is a relatively small value, for example, 0.1 A, 0.2 A, 0.3 A, 1 A, or 5 A. Then, an expected brake effect value is generated based on the test current value. The expected brake effect value represents the desired effect of braking on the vehicle. The expected brake effect value represents, for example, an expected decrease in the vehicle's speed and / or an expected decrease in the wheel angular velocity. Alternatively, the brake effect value represents an increase in the power generated by the vehicle's prime mover to maintain constant wheel speed and / or wheel angular velocity. In the case of an electric motor, the increase in power generated by the electric motor is the result of an increase in the current supplied to the electric motor by the power source. If each wheel of the vehicle is driven by an in-wheel motor, the expected brake effect is an increase in the power supplied to the in-wheel motor of the wheel associated with the electric brake motor supplied with the test current. The expected brake effect value is proportional to the test current value. For example, the expected braking effect value is obtained by referencing a look-up table, which explicitly encodes the relationship between current value and braking effect.

[0011] Next, electronic The brake power supply of the brake system must supply the test current. electronic The brake power source is, for example, the vehicle's battery. electronic It has a centralized battery that is used to power the electronic components of the vehicle, including the braking system. electronic The brake system has a dedicated power source, such as a dedicated battery. In another example, the brake power source is a fuel cell. The magnitude of the test current is equal to the test current value. For example, if the test current value is 0.1 A, a test current of 0.1 A is supplied from the brake power source to the electric brake motor. By supplying the test current to the electric brake motor, the electric brake motor is driven at a speed and / or force proportional to the test current. As a result, the brake actuator is driven by the electric brake motor, which presses the brake pads against the brake disc.

[0012] Brake effectiveness measurements are then obtained from sensors on the vehicle. The brake effectiveness measurements are electronic The sensor represents the effect on the vehicle as a result of the braking force generated by the interaction of the brake discs and brake pads of the braking system. The brake effect measurement represents, for example, a decrease in the speed of the vehicle. Alternatively or additionally, the brake effect measurement represents a decrease in the angular velocity of the wheels of the vehicle. Alternatively or additionally, the brake effect measurement represents an increase in current and / or voltage and / or power supplied to a centralized prime mover and / or in-wheel motor of the vehicle. For example, the sensor is a speed sensor for measuring the speed at which the vehicle is traveling over a surface. In another example, the sensor is an acceleration sensor for measuring the rate of deceleration and / or acceleration of the vehicle. In another example, the sensor is a power sensor for measuring the voltage and / or current and / or power supplied to the in-wheel motor or centralized prime mover of the vehicle. In another example, the sensor is an angular velocity sensor, such as a tachometer, for measuring the angular rotation of the wheels.

[0013] The obtained brake effect measurement is then compared with an expected brake effect value. For example, the expected brake effect value represents the "ideal" effect of braking action resulting from applying a test current to an electric brake motor. The obtained brake effect measurement then represents the "actual" effect of said braking action. In some cases, these values ​​differ because the brake system experiences wear that can reduce its effectiveness compared to the "ideal" standard effect. The comparison of the brake effect measurement with the expected brake effect value provides a diagnostic result. The diagnostic result therefore comprises the difference between the "ideal" effect of braking action and the "actual" effect of braking action.

[0014] In one embodiment, the diagnostic result is or comprises a percentage of the "ideal" braking performance of the electric brake that performed the braking operation. The percentage represents the ratio of the measured braking effectiveness to the expected braking effectiveness. For example, the performance of the electric brake is 70% of the expected performance of the electric brake. This means that the measured braking effectiveness is equal to 0.7 times the expected braking effectiveness.

[0015] In one embodiment, the diagnostic results are communicated to the vehicle operator. For example, if the diagnostic results exceed a first threshold, a warning is issued to the operator. The warning indicates that the vehicle needs to be inspected. In this example, if the diagnostic results exceed a second threshold, an error is issued to the operator. The error indicates a serious problem with the vehicle's braking system and indicates to the operator that the vehicle cannot be driven any further. For example, if the first threshold is 85% of expected performance, a warning is issued to the driver if the electric brake performance is less than 85%. If the second threshold is 70%, an error is issued to the driver if the electric brake performance is less than 70%.

[0016] In this way, the method electronicThe present invention provides a method for comparing the actual effect of a braking action applied to an electric brake motor of a braking system with the desired effect of the braking action, and by performing the method while the wheels of the vehicle are being driven, accurate diagnostic results are obtained by relying on sensors that measure the effect of the braking action.

[0017] In one embodiment, the method instructions are executed by a controller of the vehicle. To receive the brake effectiveness measurement, the controller receives a signal from the sensor at one of its input ports. electronic Receive a signal. electronic To command the brake power supply of the brake system, the controller electronic A signal is sent to the brake power supply.

[0018] In some embodiments, the method further comprises: Test current electronic To supply the electric brake motor of the braking system electronic receiving a speed measurement from a speed sensor prior to the step of commanding a brake power supply of the brake system, the speed sensor being configured to measure a speed of the vehicle and / or an angular velocity of a wheel, the wheel being driven by an electric wheel motor, the electric wheel motor being driven by a wheel motor power supply; Test current electronic To supply the electric brake motor of the braking system electronic The method includes the two steps of commanding a brake power supply of the braking system and then commanding a wheel motor power supply to increase the power supplied to the electric wheel motors so that the vehicle speed and / or wheel angular velocity remains equal to the speed measurement.

[0019] In this embodiment, the wheels of the vehicle are driven by electric wheel motors. For example, the electric wheel motors are centralized electric motors of the vehicle, which are configured to drive all of the wheels of the vehicle. In another example, the electric wheel motors are in-wheel motors associated with the wheels of the vehicle. In this example, each wheel has an associated dedicated in-wheel motor that powers the wheel.

[0020] To counteract the "real" braking effect resulting from the application of test current from the brake power supply to the electric brake motor, said effect must be compensated for. This is particularly desirable when the vehicle is traveling over a surface. Ideally, the vehicle operator is unaware that a diagnostic method is being performed. Therefore, the vehicle speed during the test procedure is preferably constant. Compensation for the braking effect can be achieved, for example, by increasing the power supplied to the prime mover driving the vehicle's wheels, the angular velocity of which is reduced by the braking action.

[0021] Therefore, the test current is electronic To supply the electric brake motor of the braking system electronic Prior to the step of commanding the brake power supply of the braking system, a speed measurement is obtained from a sensor of the vehicle. For example, the sensor is a speed sensor for measuring the speed at which the vehicle is traveling over a surface. In another example, the sensor is an acceleration sensor for measuring the rate of deceleration and / or acceleration of the vehicle. In another example, the sensor is an angular velocity sensor, e.g., a tachometer, for measuring the angular rotation of the wheels. Optionally, the speed measurement is obtained continuously over a period of time at a particular frequency, for example, every 0.1 seconds, or every 0.5 seconds, or every second.

[0022] Then, the test current electronic To supply the electric brake motor of the braking system electronicAfter the step of commanding the brake system's brake power supply, the wheel motor power supply is commanded to increase the power supplied to the electric wheel motors so that the vehicle's speed and / or wheel angular velocity remain equal to the speed measurements. As a result of the increase in power supplied to the electric wheel motors, the vehicle's speed and / or wheel angular velocity remain substantially equal to the measurements taken before the electric brake motors were supplied with the test current. In this manner, the diagnostic method is imperceptible or barely perceptible to the vehicle operator. Optionally, the power supplied to the electric wheel motors is continuously adjusted over a period of time after each time a speed measurement is taken at a particular frequency.

[0023] In a variation of this embodiment, the brake effectiveness measurement is received from a power sensor, the power sensor configured to measure an increase in power supplied to the electric wheel motor from a wheel motor power supply.

[0024] The braking effect is therefore characterized by an increase in power supplied to the electric wheel motors from the wheel motor power supplies. The predicted braking effect value generated by this method is therefore the predicted increase in power that should be supplied to the electric wheel motors so that the vehicle's speed and / or wheel angular velocity remain equal to the speed measurements. The "actual" braking effect, i.e., the braking effect represented by the braking effect measurements from the vehicle's sensors, represents the actual increase in power that should be supplied to the electric wheel motors so that the vehicle's speed and / or wheel angular velocity remain equal to the speed measurements. The sensor is, for example, a voltage sensor, or a current sensor, or a power sensor. The sensor is positioned to detect the power supplied to the electric wheel motors. For example, to obtain the braking effect measurement results, electronic The sensor measurement results before the brake motor of the brake system is supplied with test current are electronic The brake motor of the brake system is supplied with a test current and the sensor measurement is compared.

[0025] The braking effect measurement is thus obtained by evaluating the compensation required to offset the braking effect. There is therefore symmetry between the expected braking effect and the expected increase in power that should be supplied to the electric wheel motors so that the vehicle speed and / or wheel angular velocity remains equal to the speed measurement. Therefore, no additional sensors are required to measure the braking effect. The number of components, and therefore the complexity of the solution, is minimized.

[0026] In an embodiment, the method is performed while the vehicle and / or at least one wheel of the vehicle is being driven at a constant speed and / or velocity.

[0027] In this embodiment, the method steps are performed only when the vehicle and / or at least one wheel of the vehicle is driven at a constant speed and / or velocity. For example, the speed and / or velocity of the vehicle and / or at least one wheel of the vehicle is measured and / or monitored by a suitable sensor over a predetermined period of time. Suitable sensors are, for example, a speed sensor or speedometer or accelerometer or angular velocity sensor.

[0028] This embodiment improves the reliability of the determination of braking effect and expected braking effect. When the vehicle is moving at a constant speed and / or velocity, the effect of braking action on the vehicle is more easily predicted compared to when the vehicle is moving at a variable speed and / or velocity. When the method includes the step of increasing power supplied to the wheel prime movers of the vehicle, this embodiment reduces disruptions to the vehicle caused by the diagnostic method. The vehicle continues to travel at a constant speed and / or velocity, as expected by the driver of the vehicle.

[0029] In a variation of this embodiment, the method is performed only when the vehicle and / or at least one wheel of the vehicle is driven at a constant speed and / or rate. The method is not performed when the vehicle and / or at least one wheel of the vehicle is driven at a variable speed and / or rate.

[0030] In a variation of this embodiment, the vehicle and / or at least one wheel of the vehicle is determined to be driven at a constant speed if the vehicle and / or at least one wheel of the vehicle is driven at a constant speed for a predetermined period of time, for example, the predetermined period of time is 1 second, 5 seconds, or 10 seconds.

[0031] In one variation of this embodiment, a constant speed and / or constant velocity of the vehicle and / or at least one wheel is maintained by an automated system.

[0032] For example, the automation system is a cruise control system. The automation system regulates the amount of power generated by an engine of a vehicle. For example, the engine is a central engine powering all wheels of the vehicle. In another example, the engine comprises multiple distributed engines, each engine powering a subset of wheels of the vehicle. In another example, the engine is an in-wheel engine of the wheels of the vehicle. In this example, each wheel is driven by an associated in-wheel engine. For example, the engine is an electric engine. The automation system is, for example, fully electric, i.e., it regulates the power generated by the engine by using a "drive-by-wire" system. In this example, the automation system is implemented as a control algorithm and deployed on a control unit of the vehicle. The control unit communicates with the engine, for example, via signals sent from an output port of the control unit to an input port of the engine.

[0033] In one variation of this embodiment, the automation system is turned off by a diagnostic method, which results in a deceleration of the vehicle and / or its wheels, and the braking effect is the deceleration of the vehicle, which is measured by a suitable sensor, for example, a speed sensor, a speedometer, an accelerometer, or an angular velocity sensor.

[0034] In another variation of this embodiment, the automation system is not turned off by the diagnostic method. A constant speed and / or constant velocity of the vehicle and / or at least one wheel continues to be maintained by the automation system during execution of the diagnostic method. This results in an increase in power generated by the vehicle's engine to drive the vehicle's wheels. The braking effect is the increase in power generated by the engine. The increase in power is measured by a suitable sensor, for example, a power sensor. If the engine is an electric engine, the braking effect is the increase in power drawn by the engine to achieve the increase in power generated by the engine. The increase in power is measured by a suitable sensor, for example, a power sensor, or a voltage sensor, or a current sensor.

[0035] In some embodiments, the method further comprises, after generating the test current value and the predicted braking effect value: receiving, continuously over a defined period of time, force values ​​representative of the force with which a driver of the vehicle applies a brake pedal to the vehicle; and supplying a test current to a brake power supply of the brake system only if the force value remains constant for the determined period of time.

[0036] In this embodiment, the driver performs a braking action by pressing the brake pedal of the vehicle. The driver presses the brake pedal with a certain force. The force is measured by a suitable sensor. For example, a suitable sensor is a force transducer, such as a load cell, for example a strain gauge or a piezoelectric element. The force value received from the sensor represents the force with which the driver of the vehicle presses the brake pedal of the vehicle. The sensor measurement is performed over a defined period of time, for example 1 second, 5 seconds or 10 seconds.

[0037] In this embodiment, a test current is supplied to the brake power supply only if the force value measured by the sensor remains constant for a predetermined period of time. In this case, supplying the test current to the brake power supply adds the test current to the current supplied to the brake power supply by the driver's braking action. For example, the force applied by the driver to the brake pedal is converted into a current, such as 0.1 A, 1 A, or 5 A. For example, the test current is 0.1 A. The resultant currents supplied to the brake power supply in this example are 0.2 A, 1.1 A, and 5.1 A, respectively.

[0038] This embodiment improves the reliability of the determination of braking effect and predicted braking effect. When a driver continuously depresses the vehicle's brake pedal for a defined period of time, the vehicle decelerates at a constant rate over the defined period of time. This makes the effect of the braking action on the vehicle more easily predictable than when the vehicle decelerates at a variable rate over the defined period of time.

[0039] In one variation of this embodiment, the constant value is zero.

[0040] In this variant, the driver is not braking, since the force applied to the brake pedal of the car is 0 N. This variant further improves the reliability of the determination of the braking effect and the expected braking effect.

[0041] In one embodiment, the test current is electronic To supply the electric brake motor of the braking system electronic In the step of commanding a brake power source of the brake system, the brake power source continuously supplies a test current for a test period. electronic It is commanded to provide power to the electric brake motor of the braking system.

[0042] The test period may be, for example, 0.1 seconds, 0.5 seconds, 1 second, or 5 seconds. During the test period, a test current is continuously provided to the electric brake motor. Thus, braking effect occurs continuously during the test period. In this case, the braking effect measurement represents a continuous effect on the vehicle during the test period. For example, the braking effect is a continuous deceleration of the vehicle during the test period. In another example, the braking effect is a continuous increase in power supplied to the vehicle's engine such that the vehicle's speed and / or wheel angular velocity remain constant over the test period.

[0043] In some variations of this embodiment, the test current value is constant over the test period, for example, the test current value is 0.1 A or 0.2 A or 0.3 A or 1 A or 5 A.

[0044] In another variation of this embodiment, the test current value is variable over the test period, e.g., the test current value is a continuous function, e.g., the test current value is a sine wave or a cosine wave.

[0045] In one embodiment, electronic The braking system includes a plurality of electric brake motors and one or more sensors present on a vehicle having a plurality of wheels, each electric brake motor being associated with a respective wheel of the vehicle.

[0046] For example, a car may have two wheels, four wheels or eight wheels. Each wheel has its own brake disc and its own electronic Associated with the brakes. electronicBrakes include electric brake motors and brake pads. When a braking operation is performed, an electric brake power supply supplies current to the electric brake motors, thereby driving the electric brake motors. Each electric brake motor is further mechanically connected to a brake actuator, such as a spindle and / or a piston. The electric brake motor drives the brake actuator to move the brake pads toward and into contact with the brake disc. The interaction between the brake pads and the brake disc generates a frictional force. This frictional force reduces the rotational or angular velocity of the wheels. electronic The brakes are, for example, centrally controlled, so that each electric brake operates with the same force when a braking operation is performed. electronic The brakes are individually controlled. electronic The brakes may operate with different braking forces when a braking operation is performed.

[0047] In the step of generating a test current value and an expected braking effect value, electronic Test current values ​​and expected brake effect values ​​are generated for one or more electric brake motors of a brake system. In one example, only one test current value is generated. In another example, a respective test current value and expected brake effect value is generated for each of the one or more electric brake motors. In one variation, all generated test current values ​​are identical. In another variation, the generated test current values ​​are different. In one example, only one expected brake effect value is generated. For example, the expected brake effect value is a total deceleration of the vehicle when the electric brake motors are activated at their respective test current values. In another example, an expected brake effect value is generated for each of the one or more electric brake motors. For example, the expected brake effect value is a deceleration of the vehicle when one electric brake motor is activated at its respective test current value. In another example, the expected brake effect value is a deceleration of the rotational speed of a wheel associated with an electric brake motor activated at its respective test current value.

[0048] Test current electronic To supply the electric brake motor of the braking system electronic Instructing a brake power source of the brake system, electronic The brake power supply of the brake system must supply the test current. electronic A test current equal to a single test current value is commanded to be supplied to each electric brake motor of the brake system. electronic A test current equal to one test current value is supplied to all electric brake motors in the brake system. In another example, a test current equal to a different test current value is supplied to each electric brake motor. In yet another example, a test current equal to one test current value is supplied to one or more electric brake motors, and a test current equal to a second test current value is supplied to the remaining electric brake motors.

[0049] Braking effect measurement electronic In the receiving from a sensor of the brake system step, one or more brake effect measurements are received from one or more sensors of the vehicle, and each brake effect measurement of the one or more brake effect measurements comprises: electronic The braking effect on the vehicle as a result of the braking force generated by the interaction of each brake disc with each brake pad of the braking system, the interaction of each brake disc with each brake pad being such that each brake pad electronicIn one example, the braking effect measurement is a result of application of a test current to each electric brake motor of the braking system against a respective brake disc. For example, the single braking effect measurement is received from a single sensor. For example, the sensor is a speedometer or accelerometer configured to measure the speed and / or acceleration of the vehicle. In this case, the braking effect is a reduction in the speed and / or acceleration of the vehicle. In another example, the vehicle includes a sensor for each of the vehicle's wheels. For example, the sensor is configured to measure the angular rotation of each wheel. In this case, the braking effect is a reduction in the angular velocity of each wheel as a result of application of a test current to each electric brake motor.

[0050] In the step of obtaining a diagnostic result, the diagnostic result is obtained by comparing each brake effect measurement value with a respective expected brake effect value. Thus, the diagnostic result summarizes the comparison of the brake effect measurements with their respective expected brake effect values. For example, the diagnostic result is a comparison of the measured deceleration of the vehicle with the expected deceleration of the vehicle for each actuation of the respective brake motor by supplying the respective test current value. In another example, the diagnostic result is a comparison of the expected deceleration of the angular rotation of each wheel for each actuation of the respective brake motor by supplying the respective test current value.

[0051] Optionally, in a variation of this embodiment, each wheel of the vehicle is driven by an electric wheel motor. For example, the electric wheel motor is a centralized electric motor of the vehicle, the centralized electric motor being configured to drive all of the wheels of the vehicle. In another example, the electric wheel motor is an in-wheel motor associated with each wheel of the vehicle. In this example, each wheel has an associated dedicated in-wheel motor that powers the wheel.

[0052] To counteract the "real" braking effect resulting from the application of test current from the brake power supply to the electric brake motor, said effect must be compensated for. This is particularly desirable when the vehicle is traveling over a surface. Ideally, the vehicle operator is unaware that a diagnostic method is being performed. Therefore, the vehicle speed during the test procedure is preferably constant. Compensation for the braking effect can be achieved, for example, by increasing the power supplied to the prime mover driving the vehicle's wheels, the angular velocity of which is reduced by the braking action.

[0053] Therefore, the test current is electronic To supply the electric brake motor of the braking system electronic Prior to the step of commanding the brake power supply of the braking system, a speed measurement is obtained from a sensor of the vehicle. For example, the sensor is a speed sensor for measuring the speed at which the vehicle is traveling over a surface. In another example, the sensor is an acceleration sensor for measuring the rate of deceleration and / or acceleration of the vehicle. In another example, the sensor is an angular velocity sensor, e.g., a tachometer, for measuring the angular rotation of the wheels. Optionally, the speed measurement is obtained continuously over a period of time at a particular frequency, for example, every 0.1 seconds, or every 0.5 seconds, or every second.

[0054] Then, the test current electronic To supply the electric brake motor of the braking system electronicAfter the step of commanding the brake system's brake power source, the wheel motor power source is commanded to increase the power supplied to the electric wheel motors so that the vehicle's speed and / or the angular velocity of each wheel remains equal to the speed measurements. As a result of the increase in power supplied to the one or more electric wheel motors, the vehicle's speed and / or the wheel angular velocity remain substantially equal to the measurements taken before the electric brake motors were supplied with the test current. In this manner, the diagnostic method is imperceptible or barely perceptible to the vehicle operator. Optionally, the power supplied to the one or more electric wheel motors is continuously adjusted over a period of time after each time a speed measurement is taken at a specified frequency.

[0055] In one variation of this embodiment, in the step of generating test current values ​​and expected braking effect values, two complementary test current values ​​I1 and I2 are generated. For example, I1 is 0.1 A and I2 is 0.1 A. In another example, I1 is 0.1 A + 0.1 A * sin(t) and I2 is 0.1 A - 0.1 A * sin(t). In another example, I1 is 0.1 A + 0.1 A * sin(t) and I2 is 0.1 A + 0.1 A * sin(t). I1 and I2 are complementary, meaning that I1 and I2 are selected such that the braking effects of the two or more braking actions compensate for each other. This means that if the brakes are functioning properly, the combined braking effect of the two or more braking actions results in a constant and smooth deceleration of the vehicle and / or wheels. If one brake is malfunctioning, the combined braking effect of the two or more braking actions results in a non-constant and fluctuating deceleration of the vehicle and / or wheels. The two or more braking actions are electronic This corresponds to the application of a test current to two or more electric brake motors of the brake system, the test current being I1 or I2.

[0056] Test current electronic To supply the electric brake motor of the braking system electronicIn the step of commanding a brake power source of the brake system, the brake power source is commanded to supply a test current equal to the test current value I1 to an electric brake motor associated with a front wheel of the vehicle, and the brake power source is commanded to supply a test current equal to the test current value I2 to an electric brake motor associated with a rear wheel of the vehicle.

[0057] For example, in a vehicle having four wheels, a test current equal to test current value I1 is applied to an electric brake motor associated with a front left wheel of the vehicle, and a test current equal to test current value I2 is applied to an electric brake motor associated with a rear right wheel of the vehicle. In another example, a test current equal to test current value I1 is applied to an electric brake motor associated with a front left wheel of the vehicle, and a test current equal to test current value I2 is applied to an electric brake motor associated with a rear left wheel of the vehicle.

[0058] In an embodiment, the steps of the method are repeated at least two times, and a diagnostic result is obtained in each iteration of the method, resulting in a plurality of diagnostic results, and the method further comprises aggregating the plurality of diagnostic results to obtain an aggregated diagnostic result.

[0059] For example, the steps of the method are repeated for each wheel of the vehicle. For each wheel of the vehicle, a diagnostic result is obtained, e.g., the performance of the electric brake associated with the respective wheel. The aggregated diagnostic result comprises the performance of all electric brakes of the vehicle. In another example, a single electronic Brakes are tested multiple times and the aggregated test result is the average of the individual test results.

[0060] In one variation of this embodiment, the test current is electronic To supply the electric brake motor of the braking system electronicIn the step of commanding a brake power source of the brake system, the brake power source is commanded to supply a test current equal to a test current value I1 to an electric brake motor associated with a front wheel of the vehicle, and commanding the brake power source to supply a test current equal to a test current value I2 to an electric brake motor associated with a rear wheel of the vehicle, and the method steps are repeated at least four times.

[0061] Test current electronic To supply the electric brake motor of the braking system electronic In each iteration of commanding the brake power supply of the brake system, the brake power supply is commanded to supply test currents equal to respective test current values ​​to electric brake motors associated with different pairs of front and rear wheels of the vehicle. For example, in a first iteration of the method, the test current is first supplied to the electric brake motors of the left front and right rear wheels. In a second iteration of the method, the test current is supplied to the electric brake motors of the right front and left rear wheels. In a third iteration of the method, the test current is supplied to the electric brake motors of the left front and left rear wheels. In a fourth iteration of the method, the test current is supplied to the electric brake motors of the right front and right rear wheels.

[0062] Braking effect measurement electronic At each iteration of the step of receiving from the brake system sensors, electronic The interaction of the brake discs and brake pads in the braking system and related to the rear wheels electronic A single brake effect measurement is received that represents the braking effect on the vehicle as a result of the resultant braking force produced by the interaction of the brake discs and brake pads of the brake system.

[0063] In the step of aggregating a plurality of diagnostic results, electronic An aggregated diagnostic result is obtained that represents an estimated braking quality of each pair of interacting brake discs and brake pads of the brake system.

[0064] The invention further relates to a computer program comprising instructions that, when executed by a computer, cause the computer to perform the method according to the invention. The computer program may, for example, be implemented in software, the software being deployed on an integrated controller chip of the vehicle. In another example, the computer program may be implemented in hardware, for example using a field programmable gate array (FPGA).

[0065] The present invention further relates to a motor vehicle, comprising: Wheels and A sensor, a brake disc associated with the wheel; a brake drive including brake pads and an electric brake motor; a brake power supply configured to drive an electric brake motor of the brake drive; Controller and Equipped with electronic A braking system is provided. brake pads are positioned to interact with the brake disc to generate a braking force as a result of the brake pads being pressed against the brake disc by the electric brake motor; The sensor is configured to measure an effect on the vehicle as a result of a braking force generated by the brake pads pressing against the brake disc; The controller controls the vehicle wheels while they are being driven. generating a test current value and an expected braking effect value, the expected braking effect value being inferred from the test current value based on vehicle characteristics; commanding a brake power supply of the brake drive to supply a test current to an electric brake motor of the brake drive, the magnitude of the test current being equal to a test current value; receiving a braking effectiveness measurement from a sensor; and comparing the measured braking effectiveness value with the expected braking effectiveness value to obtain a diagnostic result.

[0066] The vehicle has at least one wheel. For example, the vehicle has two wheels, four wheels, or eight wheels. The method is performed while at least one wheel of the vehicle is driven by a prime mover. For example, at least one wheel is driven by the vehicle's centralized prime mover. The centralized prime mover is, for example, an internal combustion engine driven by the combustion of fuel or an electric motor driven by a supply of current from a power source such as a battery. In another example, the wheel is driven by an electric in-wheel motor. The in-wheel motor directly drives the associated wheel and is driven by a supply of current from a power source such as a battery. Driving the wheel causes the wheel to rotate, thereby propelling the vehicle across a surface, such as a road, at a certain speed when the vehicle is positioned on the surface. For example, if the vehicle is undergoing inspection and is positioned on a test bed with rollers for the vehicle's wheels, or if the vehicle is suspended in the air by a lifting device that does not engage the vehicle's wheels, the vehicle may remain stationary even while the wheels are rotating.

[0067] The sensor may be, for example, a speed sensor for measuring the speed at which a vehicle is traveling over a surface. In another example, the sensor may be an acceleration sensor for measuring the rate of deceleration and / or acceleration of the vehicle. In another example, the sensor may be a power sensor for measuring the voltage and / or current and / or power being supplied to an in-wheel motor or centralized prime mover of the vehicle. In another example, the sensor may be an angular velocity sensor, such as a tachometer, for measuring the angular rotation of a wheel.

[0068] Automotive electronicThe braking system includes a brake disc and a brake drive including brake pads and an electric brake motor. The brake disc is typically mechanically attached to each wheel of the vehicle, thereby following the rotation of the associated wheel. The brake pads are typically held in brake calipers, which are positioned such that the brake pads are spaced apart from the brake disc when no braking action is being performed. The vehicle also includes an electric brake motor and an electric brake power supply. When a braking action is being performed, current is supplied from the electric brake power supply to the electric brake motor, thereby driving the electric brake motor. The electric brake motor is further mechanically connected to a brake actuator, such as a spindle and / or piston. The electric brake motor drives the brake actuator to move the brake pads, which move toward and contact the brake disc. The interaction between the brake pads and the brake disc generates a frictional force. This frictional force reduces the rotational or angular velocity of the wheel. As the vehicle travels over a surface, it slows down, i.e., the vehicle's speed decreases.

[0069] The brake power source is, for example, the battery of the car. electronic It has a centralized battery that is used to power the electrical components of the vehicle, including the braking system. electronic The braking system has its own power source, such as a dedicated battery. In another example, the braking power source is a fuel cell.

[0070] The vehicle controller is configured to carry out the method according to the invention.

[0071] In some embodiments, the vehicle further comprises: a speed sensor configured to measure the speed of the vehicle and / or the angular velocity of the wheels; an electric wheel drive comprising an electric wheel motor and a wheel motor power supply, the wheel motor power supply configured to drive the electric wheel motor of the electric drive, and the electric wheel motor configured to drive the wheel; The controller further receiving a speed measurement from a speed sensor prior to commanding a brake power supply of the brake drive to supply a test current to an electric brake motor of the brake drive; after the step of commanding a brake power supply of the brake drive to supply a test current to the electric brake motor of the brake drive, commanding a wheel motor power supply of the electric wheel drive to increase the power supplied to the electric wheel motor so that the vehicle speed and / or wheel angular velocity remains equal to the speed measurement; is configured to execute

[0072] In one variation of this embodiment, the sensor is a power sensor configured to measure an increase in power supplied to the electric wheel motor from the wheel motor power supply.

[0073] In one embodiment, the vehicle includes multiple wheels and one or more sensors. electronic The brake system is a plurality of brake discs each associated with a wheel of the vehicle; a plurality of brake drives, each including a brake pad and an electric brake motor, wherein the brake power supply is configured to drive the electric brake motor of each brake drive; a brake pad of each brake drive is positioned to interact with a respective brake disc to generate a braking force as a result of the brake pad of the respective brake drive being pressed against the respective brake disc by the respective electric brake motor of the respective brake drive; each sensor configured to measure an effect on the vehicle as a result of a braking force generated by a brake pad of a brake drive pressing against a brake disc of said brake drive; electronic The brake system controller further generating test current values ​​and predicted braking effect values ​​for one or more of the plurality of brake drives, each predicted braking effect value being estimated from the test current value based on a characteristic of the vehicle; In the step of commanding the brake power sources of the brake drives to supply test currents to the electric brake motors of the brake drives, commanding the brake power sources of each of the one or more brake drives to supply a test current to the electric brake motor of the respective brake drive, the magnitude of the test current equal to the respective test current value; Braking effect measurement electronic receiving from sensors of the braking system, receiving one or more brake effectiveness measurements, each brake effectiveness measurement being received from a sensor of the one or more sensors; In the step of obtaining a diagnostic result, each of the plurality of braking effect measurement values ​​is compared with a respective expected braking effect value to obtain a diagnostic result. It is configured as follows.

[0074] In one variation of this embodiment, the controller further: In the step of generating a test current value and an expected braking effect value, two complementary test current values ​​I1 and I2 are generated; Test current electronic To supply the electric brake motor of the braking system electronicIn the step of commanding a brake power source of the brake system, the brake power source is commanded to supply a test current equal to the test current value I1 to an electric brake motor of a brake drive associated with a front wheel of the vehicle, and the brake power source is commanded to supply a test current equal to the test current value I2 to an electric brake motor of a brake drive associated with a rear wheel of the vehicle. It is configured as follows.

[0075] In a further variation of this embodiment, the controller further comprises: repeating at least four times the steps of generating a test current value and an expected brake effectiveness value, commanding a brake power source of the brake drive to supply the test current to an electric brake motor of the brake drive, receiving a brake effectiveness measurement from the sensor, and comparing the brake effectiveness measurement with the expected brake effectiveness value to obtain a diagnostic result; instructing the brake power source to supply respective test current values ​​to the electric brake motors of the brake drive associated with different pairs of front and rear wheels of the vehicle in each iteration of the step of instructing the brake power source of the brake drive to supply test currents to the electric brake motors of the brake drive; Braking effect measurement electronic At each iteration of the step of receiving from the brake system sensors, electronic Brake discs in the braking system electronic Brake system brake drive brake pads Brake drive brake pads interaction and rear wheel related electronic Brake discs in the braking system electronic receiving a single brake effect measurement representing a braking effect on the vehicle as a result of a resultant braking force produced by the interaction of the brake drive of the brake system with the brake pads; Interact electronic Brake discs and brake systems electronic Obtaining aggregated diagnostic results representing the estimated braking quality of each pair of brake pads in the brake drive of the brake system It is configured as follows.

[0076] The invention will be explained in more detail below with reference to the figures, in which exemplary embodiments of the invention are shown in a non-limiting manner. [Brief explanation of the drawings]

[0077] [Figure 1] 1 is a diagram showing a schematic view of a vehicle according to an embodiment of the vehicle of the present invention; [Figure 2] 1 is a schematic flow diagram of a method according to a first embodiment of the method according to the invention; [Figure 3] 4 is a schematic flow diagram of a method according to a second embodiment of the method according to the invention; [Figure 4] 4 is a schematic flow diagram of a method according to a third embodiment of the method according to the invention; [Figure 5] 5 is a schematic flow diagram of a method according to a fourth embodiment of the method according to the invention; [Figure 6] 5 is a schematic flow diagram of a method according to a fifth embodiment of the method according to the invention; [Figure 7] 3A-3C show schematic diagrams of current signals over time as generated in several embodiments of the method according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0078] FIG. 1 shows a schematic representation of a vehicle according to an embodiment of the vehicle according to the invention.

[0079] The vehicle 108 includes four wheels 101 a, 101 b, 101 c, and 101 d. Each wheel 101 a, 101 b, 101 c, and 101 d is associated with a respective brake disc 102 a, 102 b, 102 c, and 102 d. Each wheel 101 a, 101 b, 101 c, and 101 d is further associated with a respective brake drive. Each brake drive includes a respective brake pad 103 a, 103 b, 103 c, and 103 d. Each brake drive further includes a respective electric brake motor 104 a, 104 b, 104 c, and 104 d.

[0080] The vehicle 108 further includes a brake power supply 105. The brake power supply 105 is electrically connected to the electric brake motors 104a, 104b, 104c, and 104d, and is therefore capable of supplying power to the electric brake motors 104a, 104b, 104c, and 104d. The brake power supply 105 is a battery of the vehicle 108. The vehicle 108 is electronicThe vehicle 108 includes a centralized battery that is used to power the electrical components of the vehicle 108, including the braking system 109. The electric brake power supply 105 is configured to be commanded to provide a specified current to the electric brake motors 104a, 104b, 104c, and 104d. The command to the electric brake power supply 105 corresponds to a braking action by the driver of the vehicle 108 or an automated system of the vehicle 108. In response to the command, at least one of the electric brake motors 104a, 104b, 104c, and 104d is actuated to move at least one associated brake pad 103a, 103b, 103c, and 103d toward and into contact with at least one brake disc 102a, 102b, 102c, and 102d. The interaction of the at least one brake pad 103a, 103b, 103c, and 103d with each of the at least one brake discs 102a, 102b, 102c, and 102d creates a frictional force that slows the rotation of the vehicle 108 and / or the at least one wheel 101a, 101b, 101c, and 101d associated with the at least one brake disc 102a, 102b, 102c, and 102d. There is a relationship between: 1) the braking action, i.e., the required braking force, represented by, for example, the force with which a driver of the vehicle 108 applies the brake pedal of the vehicle 108; 2) the current required to be supplied from the brake power source 105 to the at least one electric brake motor 104a, 104b, 104c, and 104d; 3) the frictional force generated by the interaction of the at least one brake pad 103a, 103b, 103c, and 103d with the at least one brake disc 102a, 102b, 102c, and 102d; and 4) the effect of the braking action on the vehicle 108, which is the speed and / or reduction in velocity of the vehicle 108 and / or the rotational speed and / or reduction in rotational velocity of the at least one wheel 101a, 101b, 101c, and 101d associated with the at least one brake disc 102a, 102b, 102c, and 102d. The relationship between the required braking force and the required current is implemented in a look-up table.

[0081] In some cases, for various reasons, such as wear and tear, the braking effect of the vehicle 108 is reduced compared to the expected braking effect. If the braking effect is significantly reduced, the safety of the vehicle 108 is reduced. For example, the braking distance of the vehicle 108 is significantly increased. In some other cases, the braking effect of the vehicle 108 is increased compared to the expected braking effect. This is the case, for example, when the brake pads 103a, 103b, 103c, and 103d and their associated brake discs 102a, 102b, 102c, 102d are misaligned.

[0082] The vehicle 108 further comprises a sensor 106. For example, the sensor 106 is a speed sensor for measuring the speed at which the vehicle 108 is traveling over a surface. In another example, the sensor 106 is an acceleration sensor for measuring the rate of deceleration and / or acceleration of the vehicle 108. In another example, the sensor 106 is a power sensor for measuring the voltage and / or current and / or power supplied to an in-wheel motor or centralized prime mover of the vehicle 108. In another example, the sensor 106 is an angle measurement sensor, such as a tachometer, for measuring the angular rotation of the wheels.

[0083] The vehicle 108 further comprises a controller 107. The controller 107 is configured to perform a method according to any one of the embodiments of the method according to the present invention described above or below. The controller 107 is connected to the sensor 106 and configured to receive a signal from the sensor 106 through the connection to the sensor, the signal representing a braking effectiveness measurement. The controller 107 is further connected to the brake power supply 105. Through the connection to the brake power supply 105, the controller 107 can send a signal to the brake power supply 105. The signal corresponds to a request for a current, such as a test current, to be supplied from the brake power supply 105 to one or more of the electric brake motors 104a, 104b, 104c, and 104d.

[0084] The brake pads 103a, 103b, 103c, and 103d, the electric brake motors 104a, 104b, 104c, and 104d, the brake discs 102a, 102b, 102c, and 102d, the brake power supply 105, the sensor 106, and the control unit 107 are electronic A brake system 109 is formed.

[0085] Figure 2 shows a first embodiment of the method according to the invention, which diagrammatically shows the successive steps of the method in a flow chart.

[0086] The method shown in FIG. 2 involves detecting the speed of at least one wheel 101a, 101b, 101c, 101d of a vehicle 108 while the vehicle 108 is moving. electronic It is used to diagnose the braking system of the vehicle, which is the vehicle 108 shown in FIG. electronic The braking system is as shown in Figure 1. electronic Brake system 109.

[0087] The method begins with a first step S201 of generating a test current value and an expected braking effect value, where the expected braking effect value is inferred from the test current value based on the characteristics of the vehicle 108.

[0088] Next, in step S202, electronic The brake power supply of the brake system supplies a test current having a magnitude equal to the test current value while at least one of the wheels 101a, 101b, 101c, and 101d of the vehicle 108 is driven. electronic The brake motors 104a, 104b, 104c, 104d of the braking system 109 are commanded to supply power to the brake pads 103a, 103b, 103c, 103d, which contact the respective brake discs 102a, 102b, 102c, 102d, thereby creating frictional forces that reduce the rotational speed and / or velocity of the wheels 101a, 101b, 101c, 101d associated with the brake discs 102a, 102b, 102c, 102d.

[0089] Next, in step S203, electronic Brake effect measurements are received from sensors 106 on the vehicle 108 representing the effect on the vehicle 108 as a result of braking forces produced by the interaction of brake discs 102a, 102b, 102c, 102d and brake pads 103a, 103b, 103c, 103d of the braking system 109.

[0090] This allows the test current to be electronic A comparison is made between the actual effect of braking action as a result of applying it to the electric brake motors 104a, 104b, 104c, 104d of the braking system 109 and the desired effect of that braking action. By performing the method while the wheels 101a, 101b, 101c, 101d of the vehicle 108 are driven, accurate diagnostic results are obtained by relying on the sensors 106 measuring the effect of the braking action.

[0091] This embodiment will be described with reference to some examples according to the first embodiment.

[0092] In a first example, the vehicle 108 is driven by a driver who controls the speed and / or velocity of the vehicle 108 by pressing the gas pedal of the vehicle 108 .

[0093] In step S201, the test current value is, for example, 0.1 A. The expected braking effect value corresponding to this test current value is 0.2 m / s 2 This is the deceleration of the automobile 108. Therefore, it is expected that the automobile 108 will decelerate at a constant deceleration over time until it comes to a stop.

[0094] In step S202, a test current equal to 0.1 A is supplied from the brake power supply 105 to at least one of the electric brake motors 104a, 104b, 104c, and 104d, for example, to the electric brake motor 104a. The supply of the test current to the electric brake motor 104a causes the electric brake motor 104a to move the brake pad 103a toward the brake disc 102a. When the brake pad 103a contacts the brake disc 102a, a frictional force is generated, causing the vehicle to slow down.

[0095] In step S203, sensor 106 is a speed sensor used to measure the speed at which vehicle 108 is traveling over the surface. That speed can then be compared to the initial speed of vehicle 108 to infer the deceleration of vehicle 108 while the test current is applied. Alternatively, sensor 106 is an acceleration sensor used to measure the acceleration, or in this case, deceleration, of vehicle 108 while the test current is applied. The deceleration measured by the sensor may be, for example, 0.12 m / s 2 is.

[0096] Finally, in step S204, 0.2 m / s 2 The expected deceleration of 0.12 m / s is measured by sensor 106. 2 In this case, the diagnostic results show that the measured braking effect is 60% of the expected braking effect, so the braking effectiveness is reduced by 40%.

[0097] In a second example, the car 108 is driven by an automated system, such as a cruise control system, for example. The car travels at a speed of 100 km / h.

[0098] In step S201, the test current value is, for example, 0.2 A. The expected braking effect value corresponding to this test current value is 0.4 A, which is the increase in current supplied to the in-wheel motor to keep the automobile 108 running at a constant speed of 100 km / h.

[0099] In step S202, a test current equal to 0.2 A is supplied from the brake power supply 105 to at least one of the electric brake motors 104a, 104b, 104c, 104d, for example, the electric brake motor 104c. Supplying the test current to the electric brake motor 104c causes the electric brake motor 104c to move the brake pad 103c toward the brake disc 102c. When the brake pad 103c contacts the brake disc 102c, a frictional force is generated, slowing down the vehicle 108. This causes the cruise control system to respond by increasing the power supplied to the in-wheel motor associated with the wheel 101c in order to keep the vehicle traveling at a constant speed of 100 km / h.

[0100] In step S203, the sensor 106 is a current sensor used to measure the current supplied to the in-wheel motor. The measurement value obtained by the sensor 106 in this step is compared with the measurement result of the current supplied to the in-wheel motor before the test current was supplied to the electric brake motor 104c. The increase in the current supplied to the in-wheel motor is, for example, 0.36 A.

[0101] Finally, in step S204, the expected increase in current supplied to the in-wheel motor, i.e., 0.4 A, is compared with the actual increase measured by the sensor 106, i.e., 0.36 A. In this case, the diagnostic result indicates that the measured braking effectiveness is 90% of the expected braking effectiveness, so the effectiveness of the brake associated with wheel 101c is reduced by 10%.

[0102] In a third example, when the vehicle 108 is not moving, at least one of the wheels 101 a, 101 b, 101 c, and 101 d is driven. This is achieved by placing the vehicle 108 on a test bed, so that the wheels 101 a, 101 b, 101 c, and 101 d are suspended in the air or located on a rotating element. This means that the rotational speed and / or velocity of at least one of the wheels 101 a, 101 b, 101 c, and 101 d, for example wheel 101 b, is not zero, but the vehicle 108 remains stationary, i.e., the speed and / or velocity of the vehicle 108 is zero.

[0103] In step S201, the test current value is, for example, 0.5 A. The expected braking effect value corresponding to this test current value is 400 rpm of the rotation of the wheel 101b associated with the electric brake motor 104b. 2 Therefore, it is expected that the rotation of the wheel 101b will decelerate at a constant deceleration rate over time until it comes to a stop.

[0104] In step S202, a test current equal to 0.5 A is supplied from the brake power supply 105 to the electric brake motor 104b. The supply of the test current to the electric brake motor 104b causes the electric brake motor 104b to move the brake pad 103b toward the brake disc 102b. When the brake pad 103b comes into contact with the brake disc 102b, a frictional force is generated, reducing the rotational speed of the wheel 101b.

[0105] In step S203, the sensor 106 is a rotational speed sensor used to measure the rotational speed of the wheel 101b. Then, while the test current is applied, that speed is compared with the initial speed of the wheel 101b to estimate the deceleration of the wheel 101b. The deceleration measured by the sensor is, for example, 320 rpm. 2 is.

[0106] Finally, in step S204, the rotational speed is increased to 400 rpm. 2The expected deceleration of 320 rpm is measured by the sensor 106. 2 In this case, the diagnostic results show that the measured braking effect is 80% of the expected braking effect, so the braking effectiveness is reduced by 20%.

[0107] Figure 3 shows a second embodiment of the method according to the invention, which shows the successive steps of the method diagrammatically in a flow chart.

[0108] The second embodiment is an extension of the first embodiment. The method of the second embodiment implements a variation of the first embodiment and includes steps S201, S202, S203, and S204.

[0109] The method of the second embodiment further comprises step S301, in which a speed measurement is received from a speed sensor of the vehicle 108.

[0110] Step S301 in this embodiment is performed after step S201. Alternatively, step S301 is performed before step S201.

[0111] The method of the second embodiment further comprises step S302, in which a wheel motor power supply of the vehicle 108 is commanded to increase the power supplied to the electric wheel motors of the vehicle 108 such that the speed of the vehicle 108 and / or the angular velocity of at least one wheel 101a, 101b, 101c, 101d remains equal to the speed measurement.

[0112] Step S302 in this embodiment is performed after step S202 and before step S203.

[0113] This embodiment will be further described according to an example, in which the method is performed when the vehicle 108 and / or at least one wheel 101 a, 101 b, 101 c, 101 d of the vehicle 108 is driven at a constant speed and / or velocity, the speed and / or velocity of the vehicle 108 being maintained by an automated system, such as a cruise control system.

[0114] In this example, the speed sensor is a sensor configured to measure the speed of the vehicle as it moves over a surface such as a road. The sensor is a dedicated speed sensor for the vehicle and is separate from sensor 106. For example, the speed measurement received in step S301 indicates that the vehicle is traveling at a speed of 70 km / h.

[0115] Further, in this example, the wheel motor power supply is a centralized battery for the vehicle 108 and is identical to the brake power supply 105. The electric wheel motors are adapted to drive one or more wheels 101a, 101b, 101c, and 101d of the vehicle. In this example, each wheel 101a, 101b, 101c, and 101d is associated with an in-wheel motor. An in-wheel motor drives only the wheel with which it is associated. In this example, a test current is applied to the electric brake motor 104d. To mitigate the effects of the brake pad 103d pressing against the brake disc 102d, the power provided from the wheel motor power supply 105 to the electric wheel motor associated with the wheel 101d is increased. Thus, to make the diagnostic method transparent to the driver of the vehicle 108, the speed of the vehicle 108 and / or at least one of the wheels 101a, 101b, 101c, and 101d of the vehicle 108 is maintained during execution of the steps of the diagnostic method.

[0116] In this example, the sensor 106 is a power sensor configured to measure an increase in power supplied to the electric wheel motor associated with the wheel 101 d from the wheel motor power supply 105. The brake effectiveness measurement is therefore characterized by the increase in power supplied to the electric wheel motor from the wheel motor power supply 105. The diagnostic result is then characterized by the difference between the expected increase in power supplied to the electric wheel motor from the wheel motor power supply and the brake effectiveness measurement.

[0117] Figure 4 shows a third embodiment of the method according to the invention, which shows the successive steps of the method diagrammatically in a flow chart.

[0118] The third embodiment is an extension of the first embodiment. The method of the third embodiment implements a variation of the first embodiment and includes steps S201, S202, S203, and S204.

[0119] The method of the second embodiment further comprises step S401, in which force values ​​representing the force with which a driver of the vehicle 108 applies a brake pedal of the vehicle 108 are continuously received over a defined period of time.

[0120] Step S401 is performed after step S201. Alternatively, step S401 is performed before step S201.

[0121] The method of the second embodiment further comprises step S402, in which it is determined whether the force value remains constant over a defined period of time.

[0122] In this embodiment, step S202 is performed only if the force value remains constant for a predetermined test period. If the force value does not remain constant for a predetermined period, the diagnostic method returns to step S201.

[0123] In one example, in step S401, the driver of the vehicle 108 uses the vehicle's brake pedal to perform a braking operation. By pressing the brake pedal with a certain force, the brake power supply 105 is instructed to supply power to one or more electric brake motors 104a, 104b, 104c, 104d. Thus, in this embodiment, the driver is performing a braking operation during execution of the steps of the diagnostic method. Therefore, further, a current proportional to the force with which the brake pedal is pressed is supplied from the brake power supply 105 to one or more electric brake motors 104a, 104b, 104c, 104d. For example, the force applied by the driver is 100 N and the current is 3 A.

[0124] In this example, the predetermined test period is 2 seconds. In step S203, it is determined whether the driver applies a constant force to the brake pedal to obtain an accurate measurement of the braking effect. In this example, the force is measured directly by a strain gauge or a piezoelectric element connected to the brake pedal.

[0125] In this example, if it is determined in step S402 that the force value has not remained constant for a predetermined period of time, the method waits a period of 10 seconds before attempting to continue the diagnostic method.

[0126] In a variation of this example, the method continuously monitors the force with which the vehicle driver applies the brake pedal in steps S401 and S402. In this alternative example, when the condition that the force value remains constant for a predetermined period is met, the method continues to step S202. For example, the force with which the vehicle driver applies the brake pedal is monitored using a "sliding interval" equal to a predetermined test period, e.g., 5 seconds. During this sliding interval, force values ​​received from the appropriate sensors are compared. When the force value remains constant during that interval, the method continues to step S202. In this variation, the method does not return to step S201 if the force value does not remain constant for the predetermined test period. Rather, steps S401 and S402 are repeated until the force value remains constant for the predetermined period.

[0127] In this embodiment, if the force values ​​obtained from the sensors 106 remain within a 1% to 5% tolerance of each other, the force values ​​are considered to remain constant.

[0128] In this embodiment, in step S202, the magnitude of the total current supplied to at least one of the electric brake motors 104a, 104b, 104c, 104d is equal to the sum of the test current value and the current applied to the respective electric brake motor as a result of the vehicle driver's braking action. In other words, the current applied to at least one of the electric brake motors 104a, 104b, 104c, 104d is increased by an amount equal to the test current value.

[0129] Figure 5 shows a fourth embodiment of the method according to the invention, which shows the successive steps of the method diagrammatically in a flow chart.

[0130] The method shown in FIG. 5 involves driving at least one wheel 101a, 101b, 101c, 101d of a vehicle while the wheel is driven. electronic Used to diagnose the brake system 109.

[0131] In this embodiment, electronic The braking system 109 comprises a plurality of electric brake motors 104a, 104b, 104c, 104d and one or more sensors 106 present on a vehicle 108 having a plurality of wheels 101a, 101b, 101c, 101d, each electric brake motor 104a, 104b, 104c, 104d associated with a respective wheel 101a, 101b, 101c, 101d of the vehicle.

[0132] The method is electronic The method begins with a first step S501 of generating test current values ​​and expected braking effect values ​​for one or more electric brake motors 104a, 104b, 104c, 104d of the braking system 109. This step is therefore equivalent to step S201 of the first embodiment, except that one or more test current values ​​and one or more expected braking effect values ​​are generated.

[0133] Next, in step S502, electronic The brake power supply 105 of the brake system 109 outputs a test current having a magnitude equal to the test current value. electronic Each electric brake motor 104 a , 104 b , 104 c , 104 d of the brake system 109 is commanded to supply the brakes.

[0134] Next, in step S503, electronic One or more brake effect measurements are received from one or more sensors 106 on the vehicle 108 that represent the effect on the vehicle 108 as a result of braking forces generated by the interaction of each brake disc 102a, 102b, 102c, 102d and each brake pad 103a, 103b, 103c, 103d of the brake system 109.

[0135] Finally, in step S504, a diagnostic result is obtained by comparing each brake effect measurement with a respective expected brake effect value. The diagnostic result thus summarizes the comparison of the brake effect measurements with their respective expected brake effect values.

[0136] This embodiment will be described with reference to some examples according to the fourth embodiment.

[0137] In a first example, the vehicle 108 is driven by an automated system, such as a cruise control system, and is traveling at a speed of, for example, 100 km / h.

[0138] In step S501, only one test current value and only one expected braking effect value are electronic Test current values ​​are generated for each electric brake motor 104a, 104b, 104c, and 104d of the brake system 109. In this example, four test current values ​​are generated, and four expected brake effectiveness values ​​are generated. For example, the four test current values ​​are 0.1 A, 0.2 A, 0.1 A, and 0.2 A for the electric brake motors 104a, 104b, 104c, and 104d, respectively. The expected brake effectiveness values ​​corresponding to these test current values ​​are the increase in current supplied to the in-wheel motors associated with the wheels 101a, 101b, 101c, and 101d to keep the vehicle 108 traveling at a constant speed of 100 km / h. In this example, the expected brake effectiveness values ​​are 0.2 A, 0.4 A, 0.2 A, and 0.4 A for the electric brake motors 104a, 104b, 104c, and 104d, respectively.

[0139] In step S502, test currents equal to 0.1 A, 0.2 A, 0.1 A, and 0.2 A are supplied from the brake power supply 105 to the electric brake motors 104a, 104b, 104c, and 104d, respectively. The supply of the test currents to the electric brake motors 104a, 104b, 104c, and 104d causes the electric brake motors 104a, 104b, 104c, and 104d to move the brake pads 103a, 103b, 103c, and 103d toward the brake discs 102a, 102b, 102c, and 102d, respectively. When the brake pads 103a, 103b, 103c, and 103d contact the brake discs 102a, 102b, 102c, and 102d, frictional forces are generated, slowing down the vehicle 108. This causes the cruise control system to react by increasing the power supplied to the in-wheel motors associated with the wheels 101a, 101b, 101c, 101d in order to keep the car traveling at a constant speed of 100km / h.

[0140] In step S503, the sensors 106 are current sensors used to measure the current supplied to each in-wheel motor. In this example, the sensors 106 are distributed sensors, so the sensors 106 include four sensors, each associated with a respective in-wheel motor of the vehicle 108. The measurements obtained by the sensors 106 are compared with measurements of the current supplied to the in-wheel motors before the test current was supplied to the electric brake motors 104a, 104b, 104c, and 104d. The increases in current supplied to the in-wheel motors associated with the wheels 101a, 101b, 101c, and 101d are, for example, 0.1 A, 0.4 A, 0.1 A, and 0.3 A.

[0141] In step S504, each predicted braking effectiveness measurement is compared to a respective predicted braking effectiveness value. In this example, the diagnostic results indicate that the braking effectiveness associated with wheels 101a, 101b, 101c, and 101d is reduced by 50%, 0%, 50%, and 25%, respectively. Thus, the average braking effectiveness of vehicle 108 is reduced by approximately 31%.

[0142] In a second example, at least one wheel 101 a, 101 b, 101 c, 101 d is driven when the vehicle 108 is not moving. This is achieved by placing the vehicle on a test bed so that the wheels 101 a, 101 b, 101 c, 101 d are suspended in the air or located on a rotating element. This means that the rotational speed and / or velocity of at least one of the wheels 101 a, 101 b, 101 c, 101 d, for example wheel 101 b, is non-zero, but the vehicle remains stationary, i.e., the speed and / or velocity of the vehicle is zero.

[0143] In step S501, only one test current value and only one expected braking effect value are electronic For each electric brake motor 104a, 104b, 104c, and 104d in the brake system 109, four test current values ​​and four expected brake effectiveness values ​​are generated. For example, the four test current values ​​are 0.1 A, 0.2 A, 0.3 A, and 0.4 A for the electric brake motors 104a, 104b, 104c, and 104d, respectively. The brake effectiveness values ​​are calculated by applying a current of magnitude equal to each test current value. electronic This shows the expected braking effect of supplying power to each electric brake motor 104a, 104b, 104c, and 104d of the brake system 109. The expected braking effect value represents a reduction in the rotational speed of each wheel 101a, 101b, 101c, and 101d. The expected braking effect value is 80 rpm 2 , 160 rpm 2 , 240 rpm 2 , or 320 rpm 2This corresponds to the deceleration of the rotation of the wheels 101a, 101b, 101c, and 101d. Therefore, it is expected that the rotation of the wheels 101a, 101b, 101c, and 101d will decelerate at a constant deceleration over time until they come to a stop.

[0144] In step S502, test currents equal to 0.1 A, 0.2 A, 0.3 A, and 0.4 A are supplied to the electric brake motors 104a, 104b, 104c, and 104d, respectively, from the brake power supply 105. The supply of the test currents to the electric brake motors 104a, 104b, 104c, and 104d causes the electric brake motors 104a, 104b, 104c, and 104d to move the brake pads 103a, 103b, 103c, and 103d, respectively, toward the brake discs 102a, 102b, 102c, and 102d, respectively. When the brake pads 103a, 103b, 103c, and 103d come into contact with the brake discs 102a, 102b, 102c, and 102d, friction is generated that slows down the rotation of the wheels 101a, 101b, 101c, and 101d, thereby reducing the rotational speed of the wheels 101a, 101b, 101c, and 101d.

[0145] In step S503, the sensor 106 is a rotational speed sensor used to measure the rotational speed of the wheels 101a, 101b, 101c, and 101d. In this example, the sensor 106 is a distributed sensor, so the sensor 106 includes four sensors, each associated with a respective wheel 101a, 101b, 101c, and 101d of the automobile. Then, while the test current is applied, the rotational speed is compared with the initial rotational speed of each of the wheels 101a, 101b, 101c, and 101d to infer the rotational deceleration of each of the wheels 101a, 101b, 101c, and 101d. The rotational deceleration measured by the sensor is, for example, 80 rpm each. 2 , 120 rpm 2 , 120 rpm 2 , and 288 rpm 2 is.

[0146] In step S504, each predicted braking effectiveness measurement is compared to a respective predicted braking effectiveness value. In this example, the diagnostic results indicate that the effectiveness of the brakes associated with wheels 101a, 101b, 101c, and 101d is reduced by 0%, 25%, 50%, and 10%, respectively. The average braking effectiveness of vehicle 108 is reduced by approximately 21%.

[0147] Figure 6 shows a fifth embodiment of the method according to the invention, which shows the successive steps of the method diagrammatically in a flow chart.

[0148] The fifth embodiment is a modification of the fourth embodiment. The method of the fifth embodiment comprises sequential steps S601, S602, S503, and S504.

[0149] Step S601 is a variation of step S501. In step S601, two complementary test current values ​​I1 and I2 and an expected braking effect value are generated. I1 and I2 are complementary, meaning that I1 and I2 are selected such that the braking effects of the two or more braking actions compensate for each other. This means that if the brakes are functioning properly, the combined braking effect of the two or more braking actions results in a constant and smooth deceleration of the vehicle 108 and / or wheels 101a, 101b, 101c, 101d. If one brake is malfunctioning, the combined braking effect of the two or more braking actions results in a non-constant and fluctuating deceleration of the vehicle 108 and / or wheels 101a, 101b, 101c, 101d. The two or more braking actions electronic This corresponds to the application of a test current to two or more electric brake motors 104a, 104b, 104c, 104d of the brake system 109, where the test current is I1 or I2.

[0150] Step S602 is a modification of step S502. electronicThe brake power supply of the brake system 109 supplies a test current of magnitude equal to I1 to the electric brake motors 104a, 104b associated with the front wheels 101a, 101b of the vehicle 108, and supplies a test current of magnitude equal to I2 to the electric brake motors 104c, 104d associated with the rear wheels 101a, 101b of the vehicle 108.

[0151] In one example, in step S601, I1 is 0.1 A and I2 is 0.2 A. The expected braking effect value corresponding to the application of these test current values ​​is 0.3 m / s 2 This is the deceleration of the automobile 108. Therefore, it is expected that the automobile 108 will decelerate at a constant deceleration over time until it comes to a stop.

[0152] In step S602, a test current equal to 0.1 A is supplied from the brake power supply 105 to the electric brake motors 104a and 104c, and a test current equal to 0.2 A is supplied from the brake power supply 105 to the electric brake motors 104b and 104d. The supply of the test current to the electric brake motors 104a, 104b, 104c, and 104d causes the electric brake motors 104a, 104b, 104c, and 104d to move the brake pads 103a, 103b, 103c, and 103d, respectively, against the brake discs 102a, 102b, 102c, and 102d, respectively. When the brake pads 103a, 103b, 103c, and 103d come into contact with the brake discs 102a, 102b, 102c, and 102d, a frictional force is generated, slowing down the vehicle 108.

[0153] In step S503, sensor 106 is a speed sensor used to measure the speed at which the vehicle is traveling over the surface. The speed can be compared to the initial speed of the vehicle to infer the deceleration of the vehicle while the test current is applied. Alternatively, sensor 106 is an acceleration sensor used to measure the acceleration, or in this case the deceleration, of vehicle 108 while the test current is applied. The deceleration measured by the sensor is, for example, 0.24 m / s 2 is.

[0154] Finally, in step S204, 0.3 m / s 2 The expected deceleration of 0.24 m / s is compared with the actual deceleration measured by the sensor 106. 2 In this case, the diagnostic results show that the measured braking effect is 80% of the expected braking effect, so the braking effectiveness is reduced by 20%.

[0155] In another example, the vehicle 108 is driven by an automated system, such as a cruise control system, and is traveling at, for example, 100 km / h.

[0156] In step S601, I1 is 0.1 A + 0.1 A * sin(t) and I2 is 0.1 A - 0.1 A * sin(t). The expected braking effect values ​​corresponding to the application of these test current values ​​are the increase in current supplied to the in-wheel motors to keep the vehicle 108 traveling at a constant speed of 100 km / h. The expected increase is 0.2 A + 0.2 A * sin(t) for the in-wheel motors that compensate for the application of test current value I1 to each electric brake motor 104a, 104b, 104c, 104d. The expected increase is 0.2 A - 0.2 A * sin(t) for the in-wheel motors that compensate for the application of test current value I2 to each electric brake motor 104a, 104b, 104c, 104d.

[0157] In step S602, a test current equal to 0.1 A+0.1 A*sin(t) is supplied to the electric brake motors 104a and 104b from the brake power supply 105, and a test current equal to 0.1 A+0.1 A*sin(t) is supplied to the electric brake motors 104b and 104c from the brake power supply 105. The supply of the test current to the electric brake motors 104a, 104b, 104c, and 104d causes the electric brake motors 104a, 104b, 104c, and 104d to move the brake pads 103a, 103b, 103c, and 103d, respectively, toward the brake discs 102a, 102b, 102c, and 102d, respectively. When the brake pads 103a, 103b, 103c, 103d come into contact with the brake discs 102a, 102b, 102c, 102d, frictional forces are created that slow the vehicle 108.

[0158] In step S503, the sensors 106 are current sensors used to measure the current supplied to each in-wheel motor. In this example, the sensors 106 are distributed sensors, so the sensors 106 include four sensors, each associated with a respective in-wheel motor of the vehicle 108. The measurements obtained by the sensors 106 are compared with measurements of the currents supplied to the in-wheel motors before the test currents were supplied to the electric brake motors 104a, 104b, 104c, and 104d. The increase in current supplied to the in-wheel motors associated with the wheels 101a and 101d is, for example, 0.1A+0.2A*sin(t). The increase in current supplied to the in-wheel motors associated with the wheels 101b and 101c is, for example, 0.2A-0.3A*sin(t).

[0159] In step S504, each predicted braking effectiveness measurement is compared to a respective predicted braking effectiveness value. In this example, the diagnostic results indicate that the effectiveness of the brakes associated with wheels 101a and 101d has decreased by approximately 33%. In this example, the diagnostic results further indicate that the effectiveness of the brakes associated with wheels 101b and 101c has decreased by approximately 50%.

[0160] FIG. 7 shows a schematic representation of a current signal over time as generated in embodiments of the method according to the invention.

[0161] In the diagram, I is the current and t is the time.

[0162] In the first, second, and third embodiments, a test current value is generated in step S201, and in the fourth and fifth embodiments, in step S501. In some variations of these embodiments, the test current value is constant over the test period. For example, the test current value is 0.1 A, 1 A, or 5 A. This is illustrated by current signal 701.

[0163] In another variation of this embodiment, the test current value is variable over the test period. For example, the test current value is a continuous function. For example, the test current value is a sine wave or a cosine wave. This is illustrated in the figure by current signal 702.

[0164] The test period can be the entire period shown in FIG. 7 or any subperiod of the entire period. [Explanation of symbols]

[0165] 101 Wheels 102 Brake disc 103 Brake pads 104 Electric brake motor 105 Brake power supply 106 Sensors 107 Controller 108 Automobiles 109 electronic Brake system 701 Current Signal 702 Current Signal

Claims

1. 1. A method for diagnosing an electronic braking system of a motor vehicle while at least one wheel of the motor vehicle is being driven, comprising: generating a test current value and an expected braking effect value, the expected braking effect value being inferred from the test current value based on characteristics of the vehicle; instructing a brake power supply of the electronic brake system, the brake power supply being configured to drive an electric brake motor of the electronic brake system, to supply a test current to the electric brake motor of the electronic brake system, the magnitude of the test current being equal to the test current value; receiving brake effect measurements from sensors on the vehicle, the brake effect measurements representing an effect on the vehicle as a result of braking forces generated by interaction of brake discs and brake pads of the electronic brake system, the interaction between the brake discs and the brake pads being a result of the brake pads being pressed against the brake discs by the electric brake motor of the electronic brake system, the brake discs being associated with wheels of the vehicle; obtaining a diagnostic result by comparing the measured braking effectiveness value to the expected braking effectiveness value.

2. The method further comprises: receiving a speed measurement from a speed sensor before the step of commanding the brake power supply of the electronic brake system to supply the test current to the electric brake motor of the electronic brake system, the speed sensor configured to measure the speed of the vehicle and / or the angular velocity of the wheel, the wheel being driven by an electric wheel motor, the electric wheel motor being driven by a wheel motor power supply; The method further comprises:

2. The method of claim 1, comprising the step of, after commanding the brake power supply of the electronic brake system to supply the test current to the electric brake motor of the electronic brake system, commanding the wheel motor power supply to increase power supplied to the electric wheel motor such that the speed of the vehicle and / or the angular velocity of the wheel remains equal to the speed measurement.

3. The method of claim 2 , wherein the braking effectiveness measurement is received from a power sensor, the power sensor configured to measure an increase in power supplied to the electric wheel motor from the wheel motor power supply.

4. The method of claim 1 , wherein the method is performed when the vehicle and / or the at least one wheel of the vehicle is driven at a constant speed.

5. The method of claim 4 , wherein the constant speed of the vehicle and / or the at least one wheel of the vehicle is maintained by an automated system.

6. after generating the test current value and the predicted braking effect value. receiving, continuously over a predetermined period of time, force values ​​representative of a force applied by a driver of the vehicle to a brake pedal of the vehicle; and applying the test current to the brake power supply of the brake system only when the force value remains constant for the predetermined period of time.

7. The method of claim 6 , wherein the constant value is zero.

8. 2. The method of claim 1, wherein the step of commanding the brake power supply of the electronic brake system to provide the test current to the electric brake motor of the electronic brake system includes commanding the brake power supply to provide the test current to the electric brake motor of the electronic brake system continuously for a test period.

9. The method of claim 8 , wherein the test current value is constant over the test period.

10. The method of claim 8 , wherein the test current value is variable over the test period.

11. an electronic brake system including one or more sensors and a plurality of electric brake motors in a motor vehicle having a plurality of wheels, each electric brake motor being associated with a respective wheel of the motor vehicle, wherein generating the test current values ​​and the expected brake effect values ​​includes generating test current values ​​and expected brake effect values ​​for one or more of the electric brake motors of the electronic brake system; instructing the brake power supply of the electronic brake system to supply a test current to the electric brake motors of the electronic brake system, the step of instructing the brake power supply of the electronic brake system to supply a test current to each electric brake motor of the electronic brake system, the test current being equal to a respective test current value; receiving the brake effect measurements from the sensors of the electronic brake system, wherein one or more brake effect measurements are received from one or more sensors of the vehicle, each brake effect measurement of the one or more brake effect measurements representing an effect on the vehicle as a result of a braking force generated by an interaction between a respective brake disc and a respective brake pad of the electronic brake system, the interaction between the respective brake disc and the respective brake pad being a result of the respective brake pad being pressed against the respective brake disc by the respective electric brake motor of the electronic brake system; The method of claim 1 , wherein in the step of obtaining the diagnostic results, the diagnostic results are obtained by comparing each measured brake effectiveness value with a respective expected brake effectiveness value.

12. generating two complementary test current values ​​I1 and I2 in the step of generating the test current value and the expected braking effect value; 12. The method of claim 11, wherein the step of commanding the brake power supply of the electronic brake system to supply a test current to the electric brake motor of the electronic brake system includes commanding the brake power supply to supply a test current equal to the test current value I1 to an electric brake motor associated with a front wheel of the vehicle, and commanding the brake power supply to supply a test current equal to the test current value I2 to an electric brake motor associated with a rear wheel of the vehicle.

13. The steps of the method are repeated at least two times and a diagnostic result is obtained in each iteration of the method, resulting in a plurality of diagnostic results, the method further comprising: The method of claim 1 , comprising aggregating the plurality of diagnostic results to obtain an aggregated diagnostic result.

14. The steps of the method are repeated at least four times and a diagnostic result is obtained at each iteration of the method, resulting in a plurality of diagnostic results, the method further comprising: aggregating the plurality of diagnostic results to obtain an aggregated diagnostic result; instructing the brake power source of the electronic brake system to supply a test current to the electric brake motors of the electronic brake system, at each iteration of the step of instructing the brake power source to supply a test current to the electric brake motors associated with a different pair of front and rear wheels of the vehicle, the test current being equal to a respective test current value; receiving, at each iteration of the step of receiving brake effect measurements from the sensors of the electronic brake system, a single brake effect measurement representative of the braking effect on the vehicle as a result of a resultant braking force generated by the interaction of the brake discs and brake pads of the electronic brake system associated with the front wheels and the interaction of the brake discs and brake pads of the electronic brake system associated with the rear wheels; 13. The method of claim 12, further comprising: obtaining an aggregated diagnostic result representative of an estimated braking quality of each pair of interacting brake discs and brake pads of the electronic brake system in the step of aggregating the plurality of diagnostic results.

15. A computer program comprising instructions, which when executed by a computer, cause the computer to perform the method of any one of claims 1 to 14.

16. A motor vehicle, Wheels and A sensor, a brake disc associated with said wheel; a brake drive including brake pads and an electric brake motor; a brake power supply configured to drive the electric brake motor of the brake drive; Controller and and an electronic brake system comprising: the brake pads are positioned to interact with the brake disc to generate a braking force as a result of the brake pads being pressed against the brake disc by the electric brake motor; the sensor is configured to measure an effect on the vehicle as a result of the braking force generated by the brake pads pressing against the brake disc; The controller, while the wheels of the vehicle are being driven, generating a test current value and an expected braking effect value, the expected braking effect value being inferred from the test current value based on characteristics of the vehicle; commanding the brake power supply of the brake drive to supply a test current to the electric brake motor of the brake drive, the magnitude of the test current being equal to the test current value; receiving a braking effectiveness measurement from the sensor; comparing the measured braking effectiveness value with the predicted braking effectiveness value to obtain a diagnostic result; The vehicle is configured to:

17. a speed sensor configured to measure the speed of the vehicle and / or the angular speed of the wheels; an electric wheel drive comprising an electric wheel motor and a wheel motor power supply, the wheel motor power supply configured to drive the electric wheel motor of the electric wheel drive, and the electric wheel motor configured to drive the wheel; The controller further comprises: receiving a speed measurement from the speed sensor prior to the step of commanding the brake power supply of the brake drive to supply the test current to the electric brake motor of the brake drive; after the step of commanding the brake power supply of the brake drive to supply the test current to the electric brake motor of the brake drive, commanding the wheel motor power supply of the electric wheel drive to increase the power supplied to the electric wheel motor so that the speed of the vehicle and / or the angular speed of the wheel remains equal to the speed measurement; 17. The vehicle of claim 16, configured to perform the following:

18. 18. The vehicle of claim 17, wherein the sensor is a power sensor configured to measure the increase in power supplied to the electric wheel motor from the wheel motor power supply.

19. The automobile, Multiple wheels and one or more sensors; and wherein the electronic brake system of the motor vehicle comprises: a plurality of brake discs, each associated with a wheel of said vehicle; a plurality of brake drives, each including a brake pad and an electric brake motor, wherein the brake power supply is configured to drive the electric brake motor of each brake drive; the brake pads of each brake drive are arranged to interact with their respective brake discs to generate a braking force as a result of the brake pads of the respective brake drives being pressed against their respective brake discs by the respective electric brake motors of the respective brake drives; each sensor configured to measure an effect on the vehicle as a result of the braking force generated by the brake pads of a brake drive pressing against the brake discs of the brake drive; the controller of the electronic braking system further comprising: generating test current values ​​and predicted braking effect values ​​for one or more of the plurality of brake drives, each predicted braking effect value being inferred from the test current value based on characteristics of the vehicle; instructing the brake power source of the brake drive to supply a test current to the electric brake motor of the brake drive, commanding the brake power source of each of the one or more brake drives to supply a test current to the electric brake motor of the respective brake drive, wherein the magnitude of the test current is equal to a respective test current value; receiving the brake effect measurements from the sensors of the electronic brake system, wherein one or more brake effect measurements are received, each brake effect measurement being received from a sensor of the one or more sensors; In the step of obtaining the diagnostic result, each brake effect measurement value of the plurality of brake effect measurement values ​​is compared with a respective predicted brake effect value to obtain the diagnostic result.

19. A motor vehicle as claimed in any one of claims 16 to 18, configured so as to

20. The controller further comprises: generating two complementary test current values ​​I1 and I2 in the step of generating the test current value and the expected braking effect value; In the step of commanding the brake power supply of the electronic brake system to supply a test current to the electric brake motor of the electronic brake system, the brake power supply is commanded to supply a test current equal to the test current value I1 to an electric brake motor of a brake drive associated with a front wheel of the vehicle, and the brake power supply is commanded to supply a test current equal to the test current value I2 to an electric brake motor of a brake drive associated with a rear wheel of the vehicle.

20. The vehicle of claim 19, wherein the vehicle is configured as follows:

21. The controller further comprises: repeating the steps of generating a test current value and an expected brake effectiveness value, commanding the brake power source of the brake drive to supply a test current to the electric brake motor of the brake drive, receiving a brake effectiveness measurement from the sensor, and comparing the brake effectiveness measurement with the expected brake effectiveness value to obtain a diagnostic result at least four times; instructing the brake power source to supply a respective test current value to an electric brake motor of a brake drive associated with a different pair of front and rear wheels of the vehicle in each iteration of the step of instructing the brake power source of the brake drive to supply a test current to the electric brake motor of the brake drive; receiving, at each iteration of the step of receiving brake effect measurements from the sensors of the electronic brake system, a single brake effect measurement representing the braking effect on the vehicle as a result of a resultant braking force generated by the interaction of the brake discs of the electronic brake system and the brake pads of the brake drives of the electronic brake system associated with the front wheels and the interaction of the brake discs of the electronic brake system and the brake pads of the brake drives of the electronic brake system associated with the rear wheels; Obtaining an aggregated diagnostic result representing an estimated braking quality of each pair of interacting brake discs of the electronic brake system and brake pads of the brake drive of the electronic brake system.

21. The vehicle of claim 20, wherein the vehicle is configured as follows:

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