EP3573733B1

EP3573733B1 - Cruise control system for a model vehicle

Info

Publication number: EP3573733B1
Application number: EP18745262.8A
Authority: EP
Inventors: Kent Poteet; Daryl Gene SPILLMAN
Original assignee: Traxxas LP
Current assignee: Traxxas LP
Priority date: 2017-01-27
Filing date: 2018-01-29
Publication date: 2022-04-27
Anticipated expiration: 2038-01-29
Also published as: EP3573733A4; US20190358556A1; EP3573733A1; WO2018140898A1

Description

BACKGROUND

Description of the Related Art

In traditional radio-controlled model vehicles, a user must manually hold a throttle trigger at a constant position in order to maintain a constant speed when controlling the vehicle. Often, this causes an inconvenience to the user when controlling a low-speed high torque model vehicle such as a crawler model vehicle. In instances where a user is driving a crawler model vehicle to complete various obstacles in a course, the user must drive the vehicle after the completion of an obstacle to reach the next obstacle. At low speeds, the user would naturally have to maintain the throttle for an extended period of time before reaching the next obstacle. Accordingly, there is a need for a cruise control system that permits a model vehicle to automatically maintain a speed without actively controlling the throttle. US 2015/091697 discloses an example of a cruise control system for a model vehicle.

SUMMARY

The invention provides a cruise control system for a model vehicle according to claim 1 and a method for providing cruise control for a model vehicle according to claim 11.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In accordance with one embodiment is a cruise control system for a model vehicle including a transmitter. The transmitter includes a throttle input to produce a throttle command and a cruise control set input. The cruise control system further includes a receiver for receiving the throttle command and a speed controller for providing a motor command corresponding to the throttle command to a motor of a model vehicle. Wherein the throttle command and the cruise control set input are sent to the receiver and the speed controller provides a motor command based upon the throttle command at a point when the cruise control set input is activated.
In accordance with another embodiment is a cruise control system for a model vehicle including a transmitter. The transmitter includes a throttle input to produce a throttle command and a cruise control set input. The cruise control system may further include a receiver for receiving the throttle command and a speed controller for providing a motor command corresponding to the throttle command to a motor of a model vehicle. In addition, the cruise control system may include a vehicle speed sensor to measure actual vehicle speed. Wherein the throttle command and the cruise control set input are sent to the receiver and the speed controller provides a motor command based upon the throttle command at a point when the cruise control set input is activated. In addition, the motor command is adjusted based upon the actual vehicle speed.
Still in accordance with another embodiment is a method for providing cruise control for a model vehicle including receiving a throttle command from a throttle input and activating a cruise control set input. The method may further include recording the throttle command as a cruise control throttle input at a point when the cruise control set input is activated and sending a motor command to a motor based upon the cruise control throttle input while the cruise control set input is activated.
Other or alternative features will become apparent from the following description, from the drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying drawings illustrate only the various implementations described herein and are not meant to limit the scope of various technologies described herein. The drawings are as follows:

FIG. 1 illustrates a block diagram of a cruise control system in a model vehicle for maintaining a constant speed;
FIG. 2 illustrates a block diagram of the cruise control system in the model vehicle with optional speed/RPM sensors; and
FIG. 3 illustrates a logic chart of a process used by the vehicle controller to compute an output throttle for the model vehicle.

DETAILED DESCRIPTION

In the following specification, numerous specific details are set forth to provide a thorough understanding of embodiments of the present disclosure. However, those skilled in the art will appreciate that the embodiments may be practiced without such specific details. In other instances, well-known elements have been illustrated in schematic or block diagram form in order not to obscure embodiments of the present disclosure in unnecessary detail.
Some of the descriptions in the present disclosure refer to hardware components, but as those skilled in the art will appreciate, these hardware components may be used in conjunction with hardware-implemented software and/or computer software. Additionally, for the most part, specific details, and the like have been omitted inasmuch as such details are not considered necessary to obtain a complete understanding of the embodiments of the present disclosure.
FIG. 1 is a block diagram 100 illustrating a system for controlling a motor 116 in a remote controlled model vehicle to cruise or maintain a constant speed without continuous input from a throttle trigger control. A user of a model vehicle may use a transmitter 102 to provide control input to the model vehicle. Accordingly, the user manipulates the transmitter 102 to control speed and braking of the model vehicle.
The transmitter 102 comprises an antenna 104 for transmitting user input to a receiver 110. The receiver 110 also comprises an antenna 108 for receiving the user input from the transmitter 102. In some embodiments, the transmitter 102 transmits a radio frequency signal 106 to the receiver 110. The receiver 110 is coupled to a vehicle controller 118 and a speed controller 112, all which may be located on the model vehicle.
The vehicle controller 112 receives the user input from the receiver 110 and computes an output throttle to the speed controller 112. The speed controller 112 in turn translates the output throttle as motor commands to the motor 116. Overall, the battery 114 supplies the speed controller 112 with power, and the speed controller 112 can manage the speed of the model vehicle outputted by the motor 116 in response to the user input from the receiver 110.
In the embodiment shown in diagram 100, the cruise control system is implemented as an open loop control comprising of the receiver 110, vehicle controller 118, the speed controller 112, and the motor 116. Input control data is used by the cruise control system to "set" the cruise speed for the model vehicle and compute the output throttle. The model vehicle periodically executes the open control loop where the receiver 110 reads available sensor data and control input from the transmitter 102 and sends it to the vehicle controller 118.
The vehicle controller 118 in turn combines the sensor and input data to produce an output response to the steering servo and motor 116. The vehicle controller 118 combines user input throttle position sent by the transmitter 102 with throttle trim settings and ranges to compute the output throttle. The output throttle may then be sent to the speed controller 112 where it is translated to motor commands for motor 116. In this implementation of the cruise control system as an open loop control, the throttle position sent by the transmitter 102 when cruise is "set" is maintained by the logic controller and never changed. If the model vehicle travels up a hill, the maintained throttle position yields the possibility that the speed of the model vehicle may slow.
In an exemplary embodiment, the throttle is manually applied and adjusted by the user until the desired speed is achieved. The user may then "set" the current speed or throttle position of the model vehicle as the cruise speed to initiate the cruise control system before releasing the throttle. The vehicle will maintain the cruise speed until brake is applied. While cruise is set, the driver may apply positive throttle to speed up past the cruise speed and when throttle is released, the vehicle may slow to the cruise speed and resume cruise control.
In one aspect, the cruise speed of the model vehicle may be limited to a maximum speed to prevent the user from setting cruise at unsafe speeds. If the current speed being "set" for cruise is above the maximum speed, the model vehicle may engage cruise control at the maximum speed and slow the model vehicle to the maximum speed with the user releases the throttle.
FIG. 2 is a block diagram 200 illustrating an additional embodiment of the cruise control system further comprising throttle handling modifications for the transmitter 102 and an optional speed/RPM sensors 208. In this embodiment, in addition to the current throttle position of the driver throttle 206 transmitted to the remote controlled model vehicle, the transmitter 102 may be configured to further transmit two additional user inputs to the receiver 102 for the cruise control system.
The transmitter 102 may transmit additional user inputs comprising of the state of a "set" button 202 and the setting of a multi-function trim knob 204 on the transmitter 102. The user may press the "set" button 202 to set the current throttle position as the cruise speed to be implemented by the cruise control system. The multi-function trim knob 204 may be used to apply the cruise control trim settings for the transmitter 102. In an embodiment, the additional user inputs may be implemented on the actual throttle transmitter controller or a separate transmitter control device.
The transmitter controller may comprise at least one light-emitting diode (LED) 208 to indicate the trim selected by the multi-function trim knob 204, thereby enabling the user to interact with the transmitter 102 to ensure the user selects the desired trim. Accordingly, the user may press, release, and/or rotate the knob 204 in response to the LED 208 to select the desired trim.
The vehicle controller 118 may then combine the three user input data sent by the transmitter 102 to initiate the cruise control system, set the cruise speed of the model vehicle, and produce the output throttle for the model vehicle. The output throttle in turn may then be sent to the speed controller 112 where it is translated to motor commands for motor 116. Alternatively, any number of additional user inputs may be transmitted to provide additional trim and settings data for the cruise control system.
When the optional speed/RPM sensors 208 is used, the sensor 208 may provide a negative feedback control mechanism allowing the cruise control system to be implemented as a closed loop control system. When the cruise control system is implemented with the speed/RPM sensors 208, the cruise control system may "set" the initial throttle position as the cruise speed and then begin monitoring the vehicle's actual speed. When the actual speed of the vehicle changes due to external stimuli such as the model vehicle going up a hill, a speed error may be detected by the speed/RPM sensors 208. The speed error may be used by the cruise control system to output a corrective throttle response to the speed controller 112 and motor 116 so that additional throttle can be applied.
FIG. 3 illustrates a logic chart 300 of a process for a program implemented by the vehicle controller 118 to initiate the cruise control system and compute the output throttle in one embodiment of the remote controlled model vehicle system. The vehicle controller 118 process may take into account the "set" button 202 and the setting of the multifunction trim knob 204 on the transmitter 102. In the following description, the model vehicle comprises a system that accomplishes the features shown in the logic chart 300. This system may comprise a microprocessor, microcontroller, or an electronic speed control device. FIG. 3 illustrates an example of one embodiment of the claimed invention. Accordingly, the use of this example of the claimed invention does not limit the scope of the present disclosure.
To start the program, the user may accelerate the model vehicle to a desired cruise speed by manipulating the throttle control on the transmitter 102. The desired cruise speed of the model vehicle may then correspond to a current throttle position held by the user. The current throttle position may then be transmitted to the receiver 116 for initiating and implementing the cruise control system.
The receiver begins by periodically reading the current speed of the model vehicle and the transmitted throttle position in step 302 as the user forward throttles the model vehicle towards the desired cruise speed. With each reading of the model vehicle speed and throttle position received, the vehicle logic controller 118 first determines in step 304 whether the cruise control system has already been previously engaged and a setpoint recorded. The data recorded by the model vehicle when setting the setpoint may depend on whether the model vehicle is utilizing speed/RPM sensors 208 as shown in FIG. 2 or not.
The speed/RPM sensors 208 in the model vehicle may be used provide a feedback mechanism for the cruise control system. If speed/RPM sensors 208 are not used, the setpoint recorded by the model vehicle may comprise a setpoint throttle matching the current throttle position of the transmitter 102 when the "set" button 202 is pressed by the user. If speed/RPM sensors 208 are used by the model vehicle to implement a closed loop control system, the step-in recorded by the model vehicle may comprise both a setpoint throttle and a setpoint speed. The setpoint throttle would match the current throttle position of the transmitter 102 when the "set" button 202 is pressed by the user. The setpoint speed would match the current speed of the model vehicle when the "set" button 202 is pressed by the user.
If cruise control has not been previously initiated, then a determination is made in step 306 whether the new throttle position is a result of forward throttle manipulation by the user. If the received throttle position is not a result of forward throttle manipulation by the user, then the output throttle is set to the current throttle as in step 310, and the output throttle is sent by the vehicle controller 118 to the speed controller 112 in step 320. Since there was no forward throttle, this may indicate at this point that the user is maintaining and holding the throttle position at a constant position. The output throttle sent by the vehicle controller 118 should therefore remain the same and the model vehicle maintains a constant speed due to the user physically maintaining the throttle position on the transmitter 102.
If the new received throttle position in 306 is different from a previously received throttle position such that it is a result of forward throttle manipulation by the user, then a determination is made as in step 308 whether the "set" button 202 on the transmitter 102 when the current throttle position on the transmitter 102 corresponds to the desired cruise speed of the model vehicle. The user may then press the "set" button 202 to indicate to the model vehicle to initiate the cruise control system using the current throttle position of the transmitter 102.
If model vehicle receives no input control indicating that the "set" button 202 has been pressed, the logic controller 118 proceeds to set the output throttle to the current throttle in step 310 and then send the output throttle to the speed controller 112 in step 320. In this case, the forward throttle detected in step 306 is just a result of acceleration of the model vehicle by the user and the logic controller 118 communicates the increased throttle output to the speed controller 112 resulting in increased speed of the model vehicle by the motor 116.
If after determining in step 306 that the read throttle position is a result of forward throttle and the control input data transmitted by the transmitter 102 indicates that the user has pushed the "set" button 202, the model vehicle in step 312 then determines whether the output speed of the model vehicle corresponding to the current throttle position is greater than a pre-set max cruise speed. Step 312 may be optional in that the cruise control system may not be programmed to only allow cruise speed at a max speed. Alternatively, the cruise control system may have a feature to allow the user to disable the max cruise speed feature of the model vehicle.
If the max cruise speed requirement is not present or disabled, the model vehicle may pass through steps 312 and 314 and proceed to step 316 to set cruise control ON and record the setpoint for the cruise control system. The model vehicle then proceeds to step 310 to set the output throttle to the current throttle, and then step 320 to send the output throttle to the speed controller 312.
If the model vehicle is implemented with the max cruise feature and the output speed of the current throttle position is greater than the max cruise speed in step 312, the model vehicle will set the output speed to match the max cruise speed in step 314. The model vehicle would then engage the cruise control system by setting cruise control ON and record the setpoint using the max cruise throttle and correspond max cruise speed for the cruise control system in step 316.
The model vehicle may then proceeds to step 332 where a speed error between the output speed (set to the max cruise speed in step 314) and the current speed (speed > max cruise) would be detected. The model vehicle in step 332 may then compute an adjusted throttle response necessary to correct the difference between the output speed and current speed, set the output throttle to the computed adjusted throttle response, and then send the output throttle to the speed controller 312 in step 320.
If the output speed of the current throttle position in step 312 is not greater than the max cruise speed, the model vehicle proceeds to step 316 to engage the cruise control system by setting cruise control ON and recording the setpoint for the cruise control system. The model vehicle then proceeds to step 332 to set the output throttle to the current throttle. Since no speed errors would be detected in step 332, the adjusted throttle response would be the same as the current throttle, and the output throttle would therefore be set to the current throttle in step 332. In step 320, the output throttle would then be sent to the speed controller 312.
After cruise control is engaged by the model vehicle due to the user pressing the "set" button 204, the user may then release the throttle on the transmitter 102. The receiver 110 will continue to read input controls transmitted from the transmitter 102 including the released throttle position, engaging of the brakes on the controller, and manipulation of the multi-function trim knob 204.
With the cruise control now being engaged and set to ON, after reading the speed and input control data received in step 302, the logic controller 118 will proceed from step 304 to step 322. In the present embodiment shown, the user can disengage the cruise control system on the model vehicle by applying the brakes on the transmitter controller 102. Alternatively, the transmitter 102 may be configured with another button or switch to signal the model vehicle to disengage the cruise control system. In step 322, the logic controller 118 will determine whether the user has applied the brakes control on the transmitter 102.
If the brakes are applied, the cruise control is disengaged and set to OFF. The model vehicle will then set the read output throttle to the current throttle in step 310, and proceed to send the output throttle to the speed controller in step 320. The output throttle in this case may be the completely released position, in which case, the output throttle sent to the speed controller would be 0% throttle and the model vehicle would begin to operate with the motor off in a neutral setting. Alternatively, the throttle may just be at a less forward or more forward position. In this case, the cruise control would be disengaged, and the model vehicle would return to operating according to the manipulated throttle position by the user.
If in step 322, the model vehicle determines that the user did not apply the brakes to disengage the cruise control system, the model vehicle will proceed to step 326 to determine whether the current throttle position is more forward than the corresponding throttle position of the setpoint speed. As previously mentioned, when cruise control is engaged, the user may still apply forward throttle to increase the speed of the model vehicle past the cruise speed of the setpoint.
However, if a new setpoint is not recorded with regards to the additional forward throttle position currently manipulated by the user, when the throttle is released, the model vehicle will slow and return to the cruise speed of the setpoint and resume cruise control. In step 326, if the current throttle is determined to be additional forward throttle applied by the user in relation to the setpoint previously recorded, the model vehicle proceeds to step 310 and 320 to set the output throttle to the current throttle determined to be more forward than the setpoint, and send the new output throttle to the speed controller 112 to increase the speed of the model vehicle.
Alternatively, if the current throttle is determined in step 326 not to be more forward than the setpoint, such as if the user releases the throttle completely, the model vehicle proceeds to step 328 to determine whether the user has made any adjustments to the cruise control setpoint via the transmitter 102. In the present embodiment, the user may also use the multi-function trim knob 204 to adjust the cruise speed of the model vehicle by directly adjusting the setpoint.
The knob 204 may be used to increase or decrease the setpoint thereby increasing or decreasing the corresponding cruise speed, respectively. In the present embodiment, the cruise control throttle may be increased by turning the knob clockwise decreased by turning the knob counter-clockwise. The transmitter 102 may be configured with a user interface indicating to the user the corresponding adjustments being made to the cruise speed relative to the adjustments being made to the setpoint. The model vehicle may then proceed to step 330 and set the output throttle to either the original or adjusted setpoint.
As shown in FIG. 2, the cruise control system on the model vehicle may be optionally configured with additional speed/RPM sensors 208 to provide a feedback mechanism for the cruise control system. When the cruise control system is engaged, the model vehicle is maintained at a constant setpoint speed and setpoint throttle. Despite the constant setpoint throttle being applied, the speed of the model vehicle may be noticeably altered due to external stimuli such as additional friction on the road or traversing over hills. The speed/RPM sensors 208 may provide speed error negative feedback data to the vehicle controller 118 indicating that despite the constant setpoint throttle currently being applied, the current speed of the model vehicle is actually slower than the setpoint speed.
If speed/RPM sensors 208 are present on the model vehicle, the model vehicle may proceed from step 330 to 332 to adjust any speed errors or differences between the current speed and setpoint speed detected. The model vehicle in step 332 may use the speed error data received from the sensors 208 to compute an adjusted throttle response necessary for the model vehicle so the current speed of the model vehicle would also match the setpoint speed.
The output throttle would then be set to the adjusted throttle response before being transmitted to the speed controller 112. The operation of the motor 116 in accordance to the adjusted throttle response should bring the current speed of the model vehicle closer to the setpoint speed of the model vehicle previously set by the user. If no speed errors are detected, the speed error would be 0 and the output throttle would remain unchanged. If speed/RPM sensors 208 are not used on the model vehicle at all, after setting the output throttle to either the setpoint throttle or adjusted setpoint throttle in step 330, the model vehicle instead proceeds straight to step 320 and sends the output throttle to the speed controller 112.
In addition to maintaining the model vehicle at a constant high speed when controlling the model vehicle across large distances, the cruise control system may be advantageous for users controlling model vehicles such that the cruise control system may also be utilized while navigating obstacles that require low speeds and precise/technical steering. The drive may engage the cruise control system to maintaining the throttle at a low speed and focus on steering the model vehicle through the obstacles.
Elements of the embodiments have been introduced with either the articles "a" or "an." The articles are intended to mean that there are one or more of the elements. The terms "including" and "having" are intended to be inclusive such that there may be additional elements other than the elements listed. The term "or" when used with a list of at least two elements is intended to mean any element or combination of elements.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that a wide range of variations, modifications, changes, and substitutions are contemplated in the foregoing disclosure and, in some instances, some features of the present disclosure may be employed without a corresponding use of the other features
In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.
The scope of the invention is defined by the appended claims.

Claims

A cruise control system (100) for a model vehicle comprising:
a transmitter (102) comprising:
a throttle input to produce a throttle command;

a receiver (110) for receiving the throttle command; and

a speed controller (112) for providing a motor command corresponding to the throttle command to a motor of a model vehicle, characterised by a cruise control set input (202),

wherein the throttle command and the cruise control set input are sent to the receiver, and

wherein the speed controller provides a motor command based upon the throttle command at a point when the cruise control set input is activated.
The cruise control system according to claim 1, wherein the transmitter further comprises a throttle trim control for indicating throttle trim settings.
The cruise control system according to claim 1 or 2, wherein the throttle input further produces a braking command.
The cruise control system according to any preceding claim, wherein the cruise control set input comprises one or both of a push button and a rotary dial.
The cruise control system according to any preceding claim, wherein the cruise control system is an open loop system.
The cruise control system according to any preceding claim, further comprising:
a vehicle speed sensor (208),

wherein the throttle command is adjusted to maintain a measured vehicle speed provided by the vehicle speed sensor at the time the cruise control set input is activated.
The cruise control system according to any preceding claim, wherein a braking command deactivates the cruise control set input.
The cruise control system according to any preceding claim, further comprising:
a vehicle speed sensor to measure actual vehicle speed,

wherein the motor command is adjusted based upon the actual vehicle speed.
The cruise control system according to claim 8, wherein the motor command is adjusted based upon the actual vehicle speed according to a negative feedback loop.
The cruise control system according to claim 8 or 9, further comprising a cruise control indicator.
A method for providing cruise control for a model vehicle comprising:
receiving a throttle command from a throttle input;

activating a cruise control set input;

recording the throttle command as a cruise control throttle input at a point when the cruise control set input is activated;

sending a motor command to a motor based upon the cruise control throttle input while the cruise control set input is activated.
The method for providing cruise control according to claim 11, further comprising:
activating a cruise control indicator while the cruise control set input is activated.
The method for providing cruise control according to claim 11 or 12, further comprising:
measuring a vehicle speed using a vehicle speed sensor; and

adjusting the cruise control throttle input to maintain a substantially constant vehicle speed while the cruise control set input is activated.
The method for providing cruise control according to any one of claims 11 to 13, wherein the cruise control throttle input is adjusted via an open loop process.
The method for providing cruise control according to any one of claims 11 to 14, further comprising:
deactivating cruise control set input when a braking command is received from the throttle input.