Pivoting arm driver control input device

A driver control input device includes first and second base members with first and second control members each configured to support an arm of a driver and each pivotally movable with respect to the base members in a generally horizontal plane. The control members are operatively engaged with a steer-by-wire system such that pivotal movement of the first and second control members causes steering control signals to be sent to the steer-by-wire system. The control members may also be longitudinally slidably supported with respect to the base members to generate acceleration and braking signals.

TECHNICAL FIELD

The present invention relates to a vehicle driver control input device for providing steering, acceleration and braking signals on a drive-by-wire vehicle, and includes pivoting support arms for providing steering control signals.

BACKGROUND OF THE INVENTION

The implementation of drive-by-wire technology in the automotive industry (e.g. steer-by-wire, brake-by-wire, throttle-by-wire, shift-by-wire, etc.) is a result of continuing efforts to reduce cost, increase reliability, and reduce weight.

In drive-by-wire systems, mechanical devices with linkages and mechanical connections are being replaced with sensors, actuators and electronics. For example, in a conventional steering system, which consists of a steering wheel, a steering column, a power assisted rack and pinion system, and tie rods, the driver turns a steering wheel which, through the various mechanical components, causes the road wheels of the vehicle to turn. In a steer-by-wire system, a number of the mechanical components between the steering wheel and the road wheels of the vehicle are replaced with a sensor at the steering wheel and both sensors and actuators at the road wheels. In a steer-by-wire system, the rotation of the steering wheel is measured by the sensor. This rotation measurement is processed by the electronics to generate command signals for the actuators to turn the road wheels.

Drive-by-wire modules may reduce assembly time and cost and result in an improved driver interface because the elimination of mechanical connections to the steering column give engineers more flexibility in designing the driver interface with regard to location, type and performance. Vehicle designers will also have more flexibility in the placement of hardware under the hood and in the interior to support alternative power trains, enhanced styling, and improved interior functionality.

Without a steering column, there is no need to provide an adjustable seat (as a design option), so seat content may be reduced. The absence of the steering column may also enable integrated vehicle stability control systems, collision avoidance systems, and automated driving systems.

Drive-by-wire technology may also increase packaging flexibility, simplify assembly, enable tunable steering feel, and advanced vehicle control.

SUMMARY OF THE INVENTION

A driver control input device in accordance with the invention is provided for use in a vehicle drive-by-wire system for steering a vehicle. The control input device may also be used for accelerating and braking a vehicle. The invention is particularly useful in an automobile, but the driver control input device may alternatively be used in a tractor, fork-lift, other industrial vehicle, aircraft, video game, wheelchair, etc.

Advantageously, in accordance with one aspect of the invention, the driver control input device includes at least one base member (preferably first and second base members), and at least one control member (preferably first and second control members) each configured to support an arm of a driver and each pivotally movable with respect to the base members in a generally horizontal plane. The first and second control members are operatively engaged with a steer-by-wire system such that pivotal movement of the first and second control members causes steering control signals to be sent to the steer-by-wire system. The base members may be any stationary support structure.

The first and second control members may also be slidably supported with respect to the first and second base members and operatively engaged with an energy conversion system such that longitudinal sliding movement of the first and second control members causes acceleration signals to be sent to the energy conversion system. The longitudinally slidable first and second control members may be operatively engaged with a brake-by-wire system such that longitudinal sliding movement of the first and second control members causes braking signals to be sent to the brake-by-wire system.

A steering transducer may be operatively connected with the first and second control members to convert pivotal movement of the first and second control members into steering control signals. Further, an acceleration/braking transducer may be operatively connected with the first and second control members to convert longitudinal sliding movement of the first and second control members into acceleration and braking signals.

First and second hand grips may also be provided on the first and second control members, respectively. An acceleration demand input mechanism and a braking demand input mechanism may also be positioned on at least one of the hand grips to facilitate sending acceleration and braking signals to the energy conversion system and brake-by-wire system. Accordingly, redundant control of acceleration and braking may be provided.

The first and second control members are preferably sufficiently linked or synchronized such that if either control member is pivoted the other control member will rotate the same distance in the same rotational direction.

The invention also provides a vehicle including a chassis and at least three wheels operatively connected with respect to the chassis. A steering system, braking system and energy conversion system are mounted with respect to the chassis and responsive to non-mechanical control signals. The steering, braking and energy conversion systems are operatively connected to a control input device as described above.

The acceleration demand input mechanism and braking demand input mechanism may be buttons, levers, compression sensors, rheostats, or other devices.

Vehicle braking force or acceleration may be relative to the force applied to, or displacement distance of, the button, lever or control member. Preferably, when a desired speed is achieved, the accelerator buttons or control devices may be released, and the vehicle speed will be maintained, such as by cruise control. In other words, the vehicle would maintain a steady speed unless acceleration or braking signals are being sent by a driver. The first and second base members may be supported on the vehicle floor, on a post, an arm rest, vehicle chair, instrument panel, etc.

The brake actuation control devices may be linked together such that depressing either brake button, left or right, will stop the vehicle. Active force feedback is utilized to simulate vehicle dynamic conditions and enhance driving performance.

Preferably, the driver control input devices are fully adjustable to optimize user comfort.

Accordingly, each control member is pivotable about the user's elbow in the horizontal plane, and the control members are pivotable approximately 20° in either direction from the longitudinal axis of the vehicle. Pivoting the control members to the left or right will result in the vehicle's front wheels turning left or right, respectively.

The above objects, features and advantages, and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIG. 1, a vehicle10in accordance with the invention includes a vehicle drive system12and a chassis15. The vehicle drive system12includes a driver control input device11which is operatively connected with a steering system20, braking system22and energy conversion system24. The chassis15includes a frame and has four wheels16,17,18,19that are operable with respect to the chassis15. The vehicle10is preferably an automobile, but the invention also contemplates that the vehicle may be a tractor, fork-lift, or other industrial vehicle, and the control input device may be useful in an aircraft, video game, etc. Those skilled in the art will recognize materials and fastening methods suitable for attaching the wheels16,17,18, and19to the chassis15.

As shown, the driver control input device11includes first and second base members100,102supported on posts104,106, respectively. First and second control members108,110are each configured to support an arm of a driver and each pivotally movable with respect to the base members100,102in a generally horizontal plane to generate non-mechanical steering control signals52via a transducer. The transducer is preferably positioned on each base member100,102and operatively connected with the control members108,110. The steering control signals52are sent through connector wire29, through the connector ports42,28to the steering system20as the control members108,110are pivoted about a driver's elbow.

As shown, a seat21is positioned between the control members108,110to support a vehicle driver.

Additionally, the first and second control members108,110are longitudinally slidable with respect to the base members100,102, and are thereby operative to provide, via an acceleration/braking transducer, energy conversion system control signals86and electrical braking control signals66through the connector wire29and connector ports42,28to the energy conversion system24and braking system22.

The control members108,110are preferably interconnected or synchronized such that if either control member is pivoted or slid longitudinally, the other control member will move in the same manner in the same direction. The interconnection may be provided, for example, by a gearing arrangement, or by electronic synchronization using sensors to sense the positions of the control members108,110and drive motors to actuate the control members to respective synchronized positions. Preferably, the control members108,110rotate together the same distance, but they may rotate distances proportional to each other but not equal.

The steering system20, braking system22and energy conversion system24are each mounted to a frame of the chassis15and are responsive to non-mechanical control signals, as described above. The energy conversion system24is connected to a power source26. Embodiments of such systems are described subsequently with respect toFIGS. 2-4.

The chassis15includes a frame which provides a rigid structure to which the steering system20, braking system22and energy conversion system24as well as the wheels16,17,18,19are mounted, as shown schematically inFIG. 1, and is configured to support an attached body. A person of ordinary skill in the art will recognize that the chassis15can take many different forms. For example, the chassis15can be a traditional automotive frame having two or more longitudinal structural members spaced a distance apart from each other, with two or more transverse structural members spaced apart from each other and attached to both longitudinal structural members at their ends. Alternatively, the structural frame may also be in the form of a “belly pan”, wherein integrated rails and cross members are formed in sheets of metal or other suitable material, with other formations to accommodate various system components. The structural frame may also be integrated with various vehicle components. Of course, the above description is merely exemplary, and the invention may alternatively be useful in a body-on-frame assembly, body-frame integral assembly, non-passenger vehicle, such as a forklift, etc.

As described previously, the chassis15includes the connector port28, also referred to as a drive-by-wire connector port, that is mounted with respect to the chassis15and operably connected to the steering system20, braking system22and energy conversion system24. Persons skilled in the art will recognize various methods for mounting the connector port28to the chassis15. In the preferred embodiment, the connector port28is located on a top face of the chassis15, in reasonably close proximity to the driver control input device11.

The connector port28of the preferred embodiment may perform multiple functions, or select combinations thereof. First, the connector port28may function as an electrical power connector, i.e., it may be configured to transfer electrical energy generated by components on the vehicle10to the operator interface or other non-frame destination. Second, the connector port28may function as a control signal receiver, i.e., a device configured to transfer non-mechanical control signals from a non-vehicle source, such as the driver control input device11, to controlled systems including the steering system20, braking system22and energy conversion system24. Third, the connector port28may function as a feedback signal conduit through which feedback signals are made available to a vehicle driver. Fourth, the connector port28may function as an external programming interface through which software containing algorithms and data may be transmitted for use by controlled systems. Fifth, the connector port28may function as an information conduit through which sensor information and other information is made available to a vehicle driver. The connector port28may thus function as a communications and power “umbilical” port through which all communications between the vehicle and the attached driver control input device11and other attachments to the chassis are transmitted. The connector port28is essentially an electrical connector. Electrical connectors include devices configured to operably connect one or more electrical wires with other electrical wires. The wires may be spaced a distance apart to avoid any one wire causing signal interference in another wire operably connected to an electrical connector or for any reason that wires in close proximity may not be desirable.

The steering system20is operatively connected to the front wheels16,17(but may be connected to rear wheels). Preferably, the steering system20is responsive to non-mechanical control signals. In the preferred embodiment, the steering system20is by-wire. A by-wire system is characterized by control signal transmission in electrical form. In the context of the present invention, “by-wire” systems, or systems that are controllable “by-wire”, include systems configured to receive control signals in electronic form via a control signal receiver and respond in conformity to the electronic control signals.

FIG. 2is a schematic illustration of a steering system for use with the mobility system of FIG.1. The by-wire steering system20of the preferred embodiment includes a steering control unit44, and a steering actuator46. Sensors48are located on the vehicle10and transmit sensor signals50carrying information concerning the state or condition of the vehicle and its component systems. The sensors48may include position sensors, velocity sensors, acceleration sensors, pressure sensors, force and torque sensors, flow meters, temperature sensors, etc. The steering control unit44receives and processes sensor signals50from the sensors48and electrical steering control signals52from the connector port28, and generates steering actuator control signals54according to a stored algorithm. A control unit typically includes a microprocessor, ROM and RAM and appropriate input and output circuits of a known type for receiving the various input signals and for outputting the various control commands to the actuators. Sensor signals50may include yaw rate, lateral acceleration, angular wheel velocity, tie-rod force, steering angle, chassis velocity, etc.

The steering actuator46is operably connected to the front wheels16,17and configured to adjust the steering angle of the front wheels16,17in response to the steering actuator control signals54. Actuators in a by-wire system transform electronic control signals into a mechanical action or otherwise influence a system's behavior in response to the electronic control signals. Examples of actuators that may be used in a by-wire system include electromechanical actuators such as electric servomotors, translational and rotational solenoids, magnetorheological actuators, electrohydraulic actuators, and electrorheological actuators. Those skilled in the art will recognize and understand mechanisms by which the steering angle is adjusted. In the preferred embodiment, the steering actuator46is an electric drive motor configured to adjust a mechanical steering rack.

Referring toFIG. 2, the preferred embodiment of the vehicle is configured such that it is steerable by any source of compatible electrical steering control signals52connected to the connector port28. The connector port28interfits with the connector42at the connector interface53.FIG. 2depicts a steering transducer56located within the driver control input device11, operatively connected between the control members108,110and the base members100,102, and connected to a complementary connector42. Transducers convert the mechanical control signals of a vehicle driver to non-mechanical control signals. When used with a by-wire system, transducers convert the mechanical control signals to electrical control signals usable by the by-wire system. Transducers utilize sensors, typically position and force sensors, to convert the mechanical input to an electrical signal.

The complementary connector42is coupled with the connector port28of the connector interface53. The steering transducer56converts vehicle driver-initiated mechanical movement60of the control members108,110into electrical steering control signals52which are transmitted via the connector port28to the steering control unit44. The steering transducer56may include, for example, a curved rack and pinion with an optical sensor to sense the position of the pinion along the curved rack as the control members108,110are pivoted with respect to the base members100,102. A motor may also be included and operatively engaged with the pinion to provide force feedback to the driver. In the preferred embodiment, the steering control unit44generates steering feedback signals62for use by a vehicle driver and transmits the steering feedback signals62through the connector port28. Some of the sensors48monitor movement along a steering rack and vehicle speed. This information is processed by the steering control unit44according to a stored algorithm to generate the steering feedback signals62.

The steer-by-wire system described in U.S. Pat. No. 6,176,341 includes a position sensor for sensing angular position of a road wheel, a hand-operated steering wheel for controlling direction of the road wheel, a steering wheel sensor for sensing position of the steering wheel, a steering wheel actuator for actuating the hand-operated steering wheel, and a steering control unit for receiving the sensed steering wheel position and the sensed road wheel position and calculating actuator control signals, preferably including a road wheel actuator control signal and a steering wheel actuator control signal, as a function of the difference between the sensed road wheel position and the steering wheel position. The steering control unit commands the road wheel actuator to provide controlled steering of the road wheel in response to the road wheel actuator control signal. The steering control unit further commands the steering wheel actuator to provide feedback force actuation to the hand-operated steering wheel in response to the steering wheel control signal. The road wheel actuator control signal and steering wheel actuator control signal are preferably scaled to compensate for difference in gear ratio between the steering wheel and the road wheel. In addition, the road wheel actuator control signal and steering wheel actuator control signal may each have a gain set so that the road wheel control actuator signal commands greater force actuation to the road wheel than the feedback force applied to the steering wheel.

The steer-by-wire system described in U.S. Pat. No. 6,176,341 preferably implements two position control loops, one for the road wheel and one for the hand wheel. The position feedback from the steering wheel becomes a position command input for the road wheel control loop and the position feedback from the road wheel becomes a position command input for the steering wheel control loop. A road wheel error signal is calculated as the difference between the road wheel command input (steering wheel position feedback) and the road wheel position. Actuation of the road wheel is commanded in response to the road wheel error signal to provide controlled steering of the road wheel. A steering wheel error signal is calculated as the difference between the steering wheel position command (road wheel position feedback) and the steering wheel position. The hand-operated steering wheel is actuated in response to the steering wheel error signal to provide force feedback to the hand-operated steering wheel.

The steering control unit of the '341 system could be configured as a single processor or multiple processors and may include a general-purpose microprocessor-based controller, that may include a commercially available off-the-shelf controller. One example of a controller is Model No. 87C196CA microcontroller manufactured and made available from Intel Corporation of Delaware. The steering control unit preferably includes a processor and memory for storing and processing software algorithms, has a clock speed of 16 MHz, two optical encoder interfaces to read position feedbacks from each of the actuator motors, a pulse width modulation output for each motor driver, and a 5-volt regulator.

U.S. Pat. No. 6,370,460 describes a steer-by-wire control system comprising a road wheel unit and a steering wheel unit that operate together to provide steering control for the vehicle operator. A steering control unit may be employed to support performing the desired signal processing. Signals from sensors in the road wheel unit, steering wheel unit, and vehicle speed are used to calculate road wheel actuator control signals to control the direction of the vehicle and steering wheel torque commands to provide tactile feedback to the vehicle operator. An Ackerman correction may be employed to adjust the left and right road wheel angles correcting for errors in the steering geometry to ensure that the wheels will track about a common turn center.

Referring again toFIG. 1, a braking system22is mounted to the chassis15and is operably connected to the wheels16,17,18,19. The braking system22is configured to be responsive to non-mechanical control signals. In the preferred embodiment, the braking system22is by-wire, as depicted schematically inFIG. 3, wherein like reference numbers refer to like components from FIG.2. Sensors48transmit sensor signals50carrying information concerning the state or condition of the vehicle and its component systems to a braking control unit64. The braking control unit64is connected to the connector port28and is configured to receive electrical braking control signals66via the connector port28. The braking control unit64processes the sensor signals50and the electrical braking control signals66and generates braking actuator control signals68according to a stored algorithm. The braking control unit64then transmits the braking actuator control signals68to braking actuators70,72,74,76which act to reduce the angular velocity of the wheels16,17,18,19. Those skilled in the art will recognize the manner in which the braking actuators70,72,74,76act on the wheels16,17,18,19. Typically, actuators cause contact between friction elements, such as pads and disc rotors. Optionally, an electric motor may function as a braking actuator in a regenerative braking system.

The braking control unit64may also generate braking feedback signals78for use by a vehicle driver and transmit the braking feedback signals78through the connector port28. In the preferred embodiment, the braking actuators70,72,74,76apply force through a caliper to a rotor at each wheel. Some of the sensors48measure the applied force on each caliper. The braking control unit64uses this information to ensure synchronous force application to each rotor.

The preferred embodiment of the vehicle is configured such that the braking system22is responsive to any source of compatible electrical braking control signals66. At least one braking transducer80is located in the driver control input device11operatively connected between the control members108,110and the base members100,102, and connected to a complementary connector42interfitted with the connector port28at the connector interface53. The braking transducer80converts vehicle driver-initiated mechanical movement82of the control members108,110into electrical form and transmits the electrical braking control signals66to the braking control unit via the connector port28when the control members108,110are slid longitudinally with respect to the base members100,102. The braking transducer80includes sensors that measure both the rate of applied force and the amount of applied force to the control members108,110, thereby converting mechanical movement82of the control members108,110into electrical braking control signals66. The braking control unit64processes both the rate and amount of applied force to provide both normal and panic stopping.

The system described in U.S. Pat. No. 5,366,281 includes an input device for receiving mechanical braking control signals, a brake actuator and a control unit coupled to the input device and the brake actuator. The control unit receives brake commands, or electrical braking control signals, from the input device and provides actuator commands, or braking actuator control signals, to control current and voltage to the brake actuator. When a brake command is first received from the input device, the control unit outputs, for a first predetermined time period, a brake torque command to the brake actuator commanding maximum current to the actuator. After the first predetermined time period, the control unit outputs, for a second predetermined time period, a brake torque command to the brake actuator commanding voltage to the actuator responsive to the brake command and a first gain factor. After the second predetermined time period, the control unit outputs the brake torque command to the brake actuator commanding current to the actuator responsive to the brake command and a second gain factor, wherein the first gain factor is greater than the second gain factor and wherein brake initialization is responsive to the brake input.

U.S. Pat. No. 6,390,565 describes a brake-by-wire system that provides the capability of both travel and force sensors in a braking transducer connected to a brake apply input member such as a brake pedal and also provides redundancy in sensors by providing the signal from a sensor responsive to travel or position of the brake apply input member to a first control unit and the signal from a sensor responsive to force applied to a brake apply input member to a second control unit. The first and second control units are connected by a bidirectional communication link whereby each controller may communicate its received one of the sensor signals to the other control unit. In at least one of the control units, linearized versions of the signals are combined for the generation of first and second brake apply command signals for communication to braking actuators. If either control unit does not receive one of the sensor signals from the other, it nevertheless generates its braking actuator control signal on the basis of the sensor signal provided directly to it. In a preferred embodiment of the system, a control unit combines the linearized signals by choosing the largest in magnitude.

FIG. 4is a schematic illustration of the energy conversion system24referenced in FIG.1. The energy conversion system24includes an energy converter25that converts the energy stored in an energy storage system27to electrical energy that propels the vehicle12. In the preferred embodiment, the energy converter25is operably connected to a traction motor83. The energy converter25converts chemical energy into electrical energy, and the traction motor83converts the electrical energy to mechanical energy, and applies the mechanical energy to rotate the front wheels16,17. Those skilled in the art will recognize many types of energy converters25that may be employed within the scope of the present invention.

The energy conversion system24is configured to respond to non-mechanical control signals. The energy conversion system24of the preferred embodiment is controllable by-wire, as depicted in FIG.4. An energy conversion system control unit84is connected to the connector port28from which it receives electrical energy conversion system control signals86, and sensors48from which it receives sensor signals50carrying information about various vehicle conditions. In the preferred embodiment, the information conveyed by the sensor signals50to the energy conversion system control unit84includes vehicle velocity, electrical current applied, rate of acceleration of the vehicle, and motor shaft speed to ensure smooth launches and controlled acceleration. The energy conversion system control unit84is connected to an energy conversion system actuator88, and transmits energy conversion system actuator control signals90to the energy conversion system actuator88in response to the electrical energy conversion system control signals86and sensor signals50according to a stored algorithm. The energy conversion system actuator88acts on the energy conversion system24or traction motor83to adjust energy output. Those skilled in the art will recognize the various methods by which the energy conversion system actuator88may adjust the energy output of the energy conversion system.

An energy conversion system transducer92is located in the driver control input device11, operatively connected between the control members108,110and the base members100,102, and connected to a complementary connector42engaged with the connector port28at the connector interface53. The energy conversion system transducer92is configured to convert mechanical movement94of the control members108,110to electrical energy conversion system control signals86as the control members are slid longitudinally with respect to the base members100,102.

FIG. 5shows a schematic perspective view of the driver control input device11and seat21of FIG.1. As illustrated, pivotal movement of the control members108,110in the direction L indicated by the arrowheads would correspond with generation of left turning signals, and pivotal movement of the control members108,110in the direction R indicated by the arrowheads corresponds with generation of right turn signals. Also, forward sliding movement of the control members108,110in the direction B corresponds with generation of braking control signals, and rearward sliding motion of the control members108,110in the direction A corresponds with generation of acceleration signals. These directions could, of course, be reversed.

As shown, the control members108,110also include first and second hand grips112,114respectively for a driver to grasp. As shown, the hand grip112includes a braking demand input mechanism116, and the hand grip114includes an acceleration demand input mechanism118. These input mechanisms116,118are optional redundant features which provide redundant control for acceleration and braking. The braking demand input mechanism116and acceleration demand input mechanism118are shown as buttons, but could be levers, compression sensors, or other devices associated with transducers for converting mechanical driver input movements into acceleration and braking control signals. The hand grips112,114may alternatively be stick-type, palm-up type, etc.

FIG. 6shows a schematic vertical cross-sectional view taken through one of the control members of FIG.5. This figure schematically illustrates an example of how the pivoting/sliding relationship between the control member108and base member100could be executed. As shown, a track120is formed in the base member100, and includes an elongated acceleration/braking transducer member122. A slider124slides along the transducer member122in the track120. The slider124includes a force feedback motor126and a steering transducer member128. A pivoting member130is supported by the slider124, and is pivotable with respect to the slider124about the pivot axis132. The pivoting member130is fixed within the control member108so that the pivoting member130pivots with the control member108. As the pivot member130pivots with respect to the slider124, the steering transducer128senses such pivotal movement and generates steering signals accordingly to be sent to the steering system. Similarly, as the slider124is slid longitudinally along the elongated acceleration/braking transducer member122, acceleration and braking signals are generated for being sent to the energy conversion system and braking system. Preferably, if the slider124slides in a forward direction along the track122, then braking signals are generated, and if the slider124slides rearwardly120, then acceleration signals are generated.

The wire134carries braking demand signals from the braking demand input mechanism116through the control member108, base member100, and post104for communication to the braking system.

The steering, braking and acceleration systems described herein may be redundant or back-up systems to other vehicle steering, braking or acceleration systems. Also, the controls are configured redundantly such that a vehicle may be driven by one hand (i.e. the left side control member and related control features are redundant to the right side control member and related control features, etc.), therefore one control member may be eliminated.

The hand grips and control members may also be removable or collapsible for storage.

While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.